: How to check for a faulty FPR (Fuel Pressure Regulator) and replace it



Ranger
07-20-05, 03:22 PM
The FPR is a small canister mounted on the fuel rail with a vacuum hose attached to the top of it. There is a diaphram in the center of it with fuel pressure on the lower half and engine vacuum on the upper half. If the diaphram ruptures, raw fuel will leak into the intake manifold and cause a rich condition affecting fuel milage and hot engine starts. If ruptured it will act much like an applied choke on a carburated engine (aiding cold starts and hindering hot starts). To check it, simply pull the vacuum hose with the engine running (or key on, engine off) and look for fuel leaking out of the nipple. There should be none.

On the '93 & '94 4.6 Northstars the FPR is inside the intake manifold and since it is subjected to manifold vacuum, there is no need for a vacuum hose. On these engines you simply turn the key on but DO NOT start the engine as it will run away unthrottled, and look for fuel leaking at the nipple.

NOTE: the pics below are for '95+ engines. One with the old nylon fuel rail and one with the stainless steel rail.

rodsram
07-22-05, 10:27 PM
Thanks for the post Ranger. My 96 Deville started great cold but hard to start hot. Did what you said and found FPR seeping. Replaced it and starts perfect hot or cold now. Fuel mileage up too now.

rtharrs2
08-15-05, 12:00 PM
Where is the FPR on a 95 4.9L?

N0DIH
08-17-05, 01:12 PM
so one could assume that if it hold vacuum (like the one on my LT1) it is good? Or is it possible that it will with a small fuel leak and the vacuum gauge will suck against the tank and give me a false good reading?

I still haven't found the FPR on my Votrec Suburban 5700 still.

Ranger
08-17-05, 06:52 PM
Yes. I believe if it holds vacuum, it is good.

Vortec is a different breed of animal. Had one long ago but forgot most of what I knew about it. I believe it is inside the manifold. I do remember that it had some very high fuel pressure like 65 psi or so and I always blamed that for eating fuel pumps like they where going out of style.

chiucheung
12-31-05, 04:22 PM
Where is the FPR on a 98 sts

spudly
12-31-05, 07:29 PM
First off thanks to those that have answered this question in the past!

My 99 STS was starting hard and would occasionaly backfire when starting. The dealership and another mechanic could not fix the problem. I finally looked on Google and found the answer here, so again a huge thanks!

I did the inital trouble shooting and had fuel dripping out of the vaccum nipple. You could also hold the vaccum hose up close to the nipple and watch the fuel be pulled through the FPR. So even if this wasn't the main probem the FPR is shot.

Please be advised that I am no where near being a professional mechanic. So doing the FPR replacement was a little scary at first since I have had bad experiences on past cars with fuel injection.

The procedure is pretty straight forward, but the one thing that I thought would be nice would be pictures of where everything is. So as I was going through the replacement on my car I took a few pictures (all are taken standing on the drivers side of the car).

1) Remove the Beauty Cover (four 1/2" nuts)
http://home.comcast.net/~spudly55/FPR-1s.jpg

2) Under the Beauty Cover
http://home.comcast.net/~spudly55/FPR-2s.jpg

3) De-Pressurize the fuel injection system
http://home.comcast.net/~spudly55/FPR-3s.jpg
I stuffed a rag under the port and then used a corner of the rag and a pen cap to release the pressure (as has been noted before, it's like letting the air out of a bike tire).

I would always check to make sure this is de-pressurized, but I did notice that after sitting overnight there was no pressure in the system. When I got back from driving to the parts store it was completly pressurized (obviously).

4) Remove the FPR
http://home.comcast.net/~spudly55/FPR-4s.jpg
Remove the vaccum hose and the large "C" clip at the base of the unit.
Make sure you have all of the parts out before installing the new unit. The old lower gromet (The smaller of the two gromets) stuck in it's installed position along with the screen filter (a pair of needle nose pliers resolved the issue).

5) Old FPR parts
http://home.comcast.net/~spudly55/FPR-6s.jpg

6) New FPR
http://home.comcast.net/~spudly55/FPR-5s.jpg
The AC Delco unit comes with two clips. The large "C" type clip as pictures above and another "C" clip that is not used.

Also note, when installing the large "C" type clip it should go with the smaller end on top as that is what keeps the FPR in place.

7) Re-install the beauty cover and nuts.


Pretty easy procedure, the car started right up afterwards. Now I need to wait for it to get warm and see how it works then, but I have no doubt this was the issue.

mcowden
12-31-05, 09:03 PM
GREAT STUFF SPUDLY!!! We should have done this long ago. Thank you very much for posting such a helpful and informative tip. I'm sure this will get moved to the Tech Tips or Technical Archive sections for all to use. Many people ask this question, and to date we don't have any replies with a photo record such as this.

Glad you were able to solve your car's starting problem using this site, a big THANK YOU for your post, and a warm welcome to Cadillac Forums... :welcome: Your first post is a great one! :thumbsup:

Caddyshack100
12-31-05, 09:27 PM
Great photos, I have owned a fair number of gm cars (fords, 3 Broncos, dodge chargers 2,) but none of them have ever had a problem with the FPR. Is this a problem with the Northstar? I did not think the fuel pressure would be any greater than any other gm SEFI. Also is the fuel filter held connected by one threaded end and one plastic connector, or has gm seen the light and used two plastic clips (such as Ford uses)

danbuc
12-31-05, 09:33 PM
Hmmm...that reminds me. I've been meaning to check my FPR for a while now for leaks, but I've been real lazy about it. Thanks for the pics though.

Closet Boy
12-31-05, 10:21 PM
Super pics! Great info! Thanks!

spudly
01-15-06, 05:56 AM
Just a follow up on this since it has been a few weeks since the replacement.

This has solved quite a few problems I was having with the car.
1) Hard starting, bad when cold really bad when warm
2) Backfiring
3) Surging when stopped

Now I need to work on getting the struts and shocks replaced and then on to getting a new set of tires to eliminate that damn shimmy from 65-75.

tbombaci
02-04-06, 01:01 PM
Thank you!!

I recently have had all of the symptoms and more.

I first did a tune up to try and resolve the issue. The tune up helped, but we were still having all of the FPR related problems.

I just replaced the FPR and did a test drive. Runs like a dream.

Regards,
Tom Bombaci

'95 SLS

jmmast02
02-07-06, 02:52 PM
Could some one please help me with a part number for the FPR so I can check and see the price on unit from gmpartsdirect.com. I am at school and do not have tools, but I am certain that this is the problem. Much appreciated. 1998 Seville SLS

tbombaci
02-07-06, 03:34 PM
From the package:

ACD# 217-1629
GM# 12499841

I paid $71 with California tax for the kit from a local Cadillac dealer.

You will only need two tools for the job:

1. 1/2" ratchet or nut driver to get the beauty cover off
2. a small screw driver to pull the clamp from the FPR

It is a super easy repair.

Also, there are two types of FPR’s (according to the parts guy at the counter). They asked if I had a plastic fuel rail or the new stainless steel rail.

I had my fuel rail replaced via a recall notice. The plastic rail will eventually leak gas.

-Tom

jamesmdx1
02-10-06, 09:54 PM
Hi

does the 94 N* have the fuel rails that had to be replaced?
thanks

Ranger
02-11-06, 09:24 AM
Hi

does the 94 N* have the fuel rails that had to be replaced?
thanks
No. The recall is for '95 - '97.

Caddysodry
03-02-06, 07:21 PM
Any ideas where a FPR is on a 93 seville? My car starts ok but the gas milage is bad.

Ranger
03-02-06, 08:13 PM
The '93/'94 FPR is inside the intake manifold. Remove the top cover. Since it is inside the manifold it is subjected to manifold vacuum, hence no need for a vacuum hose. When you go key on to pressurize the fuel system, DO NOT crank the engine. If it starts, it will run away at WOT and bounce off the rev limiter as it will be unthrottled.

CadillacLuv
03-07-06, 02:21 AM
What part is the hose that should be pulled and checked for leaking. I don't want to screw up my baby...

Ranger
03-07-06, 11:47 AM
I don't understand your question. Just pull the vacuum hose off the FPR and look for fuel leaking from the nipple.

a.johnson1
03-21-06, 08:29 PM
my 97 deville starts just fine when the engine is warmed up or has been driven, but is getting almost impossible to start when the engine is cold, this morning i had to crank it 7-10 times when it did start it was runnig like crap, does anyone think this could be my problem?

Ranger
03-21-06, 10:12 PM
Check your fuel pump relay. Remove the gas cap. Put your ear to the filler pipe and have someone turn the key On (Don't crank). You should hear the pump run for about 2-3 seconds. If not, the relay is probably bad. In that case, the engine must build enough oil pressure to enable the oil pressure switch to override the relay and power the fuel pump.

a.johnson1
03-22-06, 05:14 PM
I checked the fuel pump relay. The pump is working fine. what about the cold start sensor. its only hard to start when the engine is cold (it seems worse during colder weather) like a carburated car with the choke stuck open. after it starts up the first time it usually starts good until it sets for a while, (usually over night). I just bought the car about a month ago. it started fine when we test drove it. About a week after we bought it my wife told me she had to crank the car a couple of times before it would start and it has been getting worse since then. thank you for the advice. and more would be great.

behind-bars
03-22-06, 05:17 PM
I believe I have found the FPR on my 4.9L (93 Sedan Deville) Since it is not a N* it does not have a beauty cover, but it looks similar to the one pictured and is just to the driver side of the throttle body sort of under the air intake housing.

I havent checked it recently, last time I checked a few months back I did not see a leak with engine on or off, so I figured it is good. Lately though the car has become hard to start when warm, After driving around and stopping for a few minutes then restarting I have to hold the key all the way over for several seconds for it to start up, Yet it always starts first try when cold, like first thing in the morning or when I leave work/school after a few hours.

I have just had the starter replaced twice in the last year or so, before I had it done the first time it got hard to start no matter hot/cold. After replacing it all was well for a month, then with no warning I was stuck at a gas station unabable to get it started. After checking and replacing the battery I had it towed back in and they replaced the entire starter and it was fine up until recently when I have hot start troubles every time.

My question is how do I troubleshoot this to determine if this is a sign of my starter going out again, or an FPR issue. I havent seen any leaks at all every time I checked it, Any other way to test starter or the fpr without just replacing it?


EDIT for a.johnson1
Have you checked for any problems with the starter? If its constantly getting worse no matter cold or hot it sounds like what I just described. You mention your problem started with cold starts, I wasnt sure if your hot starts have started to be more difficult or not. Maybe describing the sound it makes may help lol :bigroll: When I had my starter trouble it was sort of a whining sound, never sounded like it tried to turn over.

a.johnson1
03-22-06, 05:39 PM
I think the starter is ok. it turns over good, fast not dragging.The sound is like when your car is out of gas and you try to start it, and it almost starts for a second and then dies. it is a lot like that but i have plenty of gas.

Ranger
03-22-06, 06:04 PM
I believe I have found the FPR on my 4.9L (93 Sedan Deville) Since it is not a N* it does not have a beauty cover, but it looks similar to the one pictured and is just to the driver side of the throttle body sort of under the air intake housing.

I havent checked it recently, last time I checked a few months back I did not see a leak with engine on or off, so I figured it is good. Lately though the car has become hard to start when warm, After driving around and stopping for a few minutes then restarting I have to hold the key all the way over for several seconds for it to start up, Yet it always starts first try when cold, like first thing in the morning or when I leave work/school after a few hours.

I have just had the starter replaced twice in the last year or so, before I had it done the first time it got hard to start no matter hot/cold. After replacing it all was well for a month, then with no warning I was stuck at a gas station unabable to get it started. After checking and replacing the battery I had it towed back in and they replaced the entire starter and it was fine up until recently when I have hot start troubles every time.

My question is how do I troubleshoot this to determine if this is a sign of my starter going out again, or an FPR issue. I havent seen any leaks at all every time I checked it, Any other way to test starter or the fpr without just replacing it?

If the engine cranks, the starter is doing what it was designed to do. The first post will tell you how to check the FPR.

Ranger
03-22-06, 06:07 PM
I checked the fuel pump relay. The pump is working fine. what about the cold start sensor. its only hard to start when the engine is cold (it seems worse during colder weather) like a carburated car with the choke stuck open. after it starts up the first time it usually starts good until it sets for a while, (usually over night). I just bought the car about a month ago. it started fine when we test drove it. About a week after we bought it my wife told me she had to crank the car a couple of times before it would start and it has been getting worse since then. thank you for the advice. and more would be great.
There is no "cold start sensor". Maybe a leaky injector (flooded engine). Have you tried starting it with your foot on the floor (clear flood mode)?

a.johnson1
03-22-06, 06:44 PM
i tried to start it while holding the gas pedal on the floor. didnt start. since there is not a cold start sensor in my caddy what would be like a choke? As soon as it starts you can kill it and it starts right back up no problem i dont get it. do you have any other ideas?:confused:

Ranger
03-22-06, 07:30 PM
Well, PCM reads coolant temp to determine that the engine is cold and richens the mixture (so to speak).

a.johnson1
03-22-06, 08:24 PM
just got back from orreillys website they have a coolant temperature sensor
for the fuel injection, not for the gauge,or emissions. im not positive on its location it should screw in somewhere. i replaced one on a late 90s gmc with almost identical symptoms it was on the front end of the intake. do you think its worth 20 bucks to give it a whirl? Also do you know what the fuel pressure should be?

Ranger
03-24-06, 08:17 PM
I suppose for $20 it might be worth a shot. Fuel pressure should be about 45 psi if memory serves me correctly.

a.johnson1
03-25-06, 10:14 AM
thank you Ranger for all the advice it was very usefull in narrowing down my cars problem. :thumbsup: I dont have the sensor yet, but when i get it in i will let you know if it helps. Thanks again Ranger :highfive:


Austin Johnson

AnotherToothpick
03-26-06, 12:28 AM
Where might I find the FPR on a 4.9L engine, and furthermore, should I even bother? What I mean to say is, was this a N*-specific issue?

I'm trying to pin down whatever may be causing various problems I've been experiencing, including extremely poor milage (<10mpg), a very rough idle (800-1000rpm), and sporadic knocking.

behind-bars
03-26-06, 01:43 AM
Where might I find the FPR on a 4.9L engine, and furthermore, should I even bother? What I mean to say is, was this a N*-specific issue?

I'm trying to pin down whatever may be causing various problems I've been experiencing, including extremely poor milage (<10mpg), a very rough idle (800-1000rpm), and sporadic knocking.

i think i found it on the 4.9. Look under the air filter housing, It has a vacuum hose coming out the side if I am correct. Looks sorta like the one in the picture but is attached differently.

For the poor mileage I would suggest replacing the oxygen sensor, it is located just infront of the firewall and just behind the engine in the exhaust system. It brought my mileage from 9 to almost 14 without giving a service engine light. Also have you done the plugs/wires cap/rotor on it recently?

Knocking may be caused by cheap gas, bad timing ( which may cause Idle problems to) or problems with the egr tubes or solenoid/valve ( which could affect all 3 problems)

I would start with the cheap/free fixes first and clean the throttle body and egr delivery tubes which could raise mileage and cut knocking, also get on the oxygen sensor if you haven't, its only 20 dollars to replace and easy to do yourelf. And check your timing also.

If you haven't done the ignition system stuff like plugs,wires, dist. cap I would do that as well.

And push off and warmer to get any error messages to help you guide your searching.

The FPR can fail on any engine so its worth a check.

I think all of the above has been covered well indepth in other threads that I have seen.
Search "clean egr tubes" aaswell as "tuneup" and "o2 sensor" for a good start

AnotherToothpick
03-26-06, 10:29 AM
Thanks for the excellent response! Actually I've only had the Seville for about 2000 miles. It was previously a granny-mobile, so I got it with very low milage ($3000 with 65k). Of course, due to the nature of its previous ownership, many fluids were in dire need of changing, and it appears from the very limited records I got with it that no work had been done on it... at all. And to add to that, the car sat undriven in a parking lot for several months before I came along and bought it.

In conclusion, if it can be cleaned, tuned, replaced, etc., I assume that it probably needs to be. I'll check out the FPR, and I'll definitely grab an O2 sensor if they're really that cheap. I'll also check out those tune-up threads you mentioned... Thanks!

illumina
03-27-06, 07:00 PM
I have one for you Ranger:

On my 1991 Seville, I have an aftermarket FPR from Aeromotive that is also a boost-referenced regulator (no boost yet :( ). It is set at 2 PSI above stock ratings. As of late, I have been having some serious cold-start issues to where I have to either crank the engine for several seconds or turn the key off and on enough to build fuel pressure...

I immediately checked the fuel pressure regulator at the vaccum port for leaks, to which I found none. The next thing I tested was the fuel pressure: upon initially turning the key, the fuel pump arms and the fuel pressure rises to where it should be, then it drops to near zero...As mentioned before, I have to turn the key several times again without actually starting the car to get the fuel pressure to stay constant and I also do that so I don't fry the starter (just replaced a bad one today).

Any thoughts on this man?

Ranger
03-27-06, 07:25 PM
WOW, sudden drop in pressure. If the pump quit operating, I would think the pressure would slowly drop as the injectors bled of the pressure. Since this is a sudden drop, something is dumping fuel back into the tank via the return line very quickly. Since you just replaced the FPR, and it is aftermarket, it would be highly suspect. That is where I would start. I am just applying some logic to what little I know of how the system works and taking a shot in the dark (from the hip).

illumina
03-27-06, 07:33 PM
WOW, sudden drop in pressure. If the pump quit operating, I would think the pressure would slowly drop as the injectors bled of the pressure. Since this is a sudden drop, something is dumping fuel back into the tank via the return line very quickly. Since you just replaced the FPR, and it is aftermarket, it would be highly suspect. That is where I would start. I am just applying some logic to what little I know of how the system works and taking a shot in the dark (from the hip).

Shazbot!

Yeah, the pressure doesn't hold well at all on initial startup and I have to basically 'prime' the system before I waste energy on the starter by over-cranking.

I've had this regulator on for well over a year, but that doesn't mean that it can't go bad, right? I still have a few old ones laying around that should still be good, so this weekend I'll drop one of those back on and see if that cures the problem and perhaps replace my adjustable regulator.

Thanks for the prompt response :thumbsup:

Ranger
03-27-06, 07:43 PM
If that regulator is adjustable, maybe you can adjust it. It is pretty obvious that something is opening the flood gates and if I understand the fuel routing correctly, the return gate is the FPR.

illumina
03-27-06, 08:00 PM
If that regulator is adjustable, maybe you can adjust it. It is pretty obvious that something is opening the flood gates and if I understand the fuel routing correctly, the return gate is the FPR.

That or something inside of the FPR is stuck open if such a thing can happen. If I recall correctly, this particualr PFR can be opened for repairs...I'll look into it and see what happens.

Tailfin
03-28-06, 03:30 AM
Is it also possible that the check ball in the fuel pump isn't seating at all? Just an additional shot in the dark lol...but damn, I wouldn't want to tear that down just to find out...kick the gas tank :rolleyes:

Firewireman
03-29-06, 08:49 PM
Can someone validate the size for me? I just bought one tonight and am putting it on tomorrow. I have a 99STS.

http://www.hometown.aol.com/singtiger/images/dscf0980.jpg

sunpowered
04-07-06, 12:56 PM
From the package:

ACD# 217-1629
GM# 12499841

I paid $71 with California tax for the kit from a local Cadillac dealer.

You will only need two tools for the job:

1. 1/2" ratchet or nut driver to get the beauty cover off
2. a small screw driver to pull the clamp from the FPR

It is a super easy repair.

Also, there are two types of FPRs (according to the parts guy at the counter). They asked if I had a plastic fuel rail or the new stainless steel rail.

I had my fuel rail replaced via a recall notice. The plastic rail will eventually leak gas.

-Tom

ok if there are two types of FPR and it makes a difference when ordering which fuel rail you have, then doe it not stand to reason that when they do the fuel rail recall that they would have to replace the FPR to fix with the correct fuel rail.And would this not answer alot of the problems folks have had after the fuel rail recall fix?

Rich_M
04-14-06, 08:42 PM
ok if there are two types of FPR and it makes a difference when ordering which fuel rail you have, then doe it not stand to reason that when they do the fuel rail recall that they would have to replace the FPR to fix with the correct fuel rail.And would this not answer alot of the problems folks have had after the fuel rail recall fix?

I asked that question when I had the fuel line recall done. I was told that they use your original FPR. (They do check it) I think the retainer clip is different.

Regards,
Rich

acfcrown
04-24-06, 10:52 PM
I Need Help!!!! My Problem Is Oppsite Of What Everyone Is Saying- My 96 Deville Sputters And Is Very Hard To Start When Cold - But Then Starts Easily All Day Long - Still The Fpr ?

94CaddyConcours
04-25-06, 09:16 PM
OK i'm about to freak out. I dont have a vacum hose on my FPR. BTW its a 1994 De Ville Concours. And also to remove the for my car 93-94 the you need to remove 10 T30 bolts. It was a bitch to get the last two because it was not black but steel color. Somone point out what is going on. After I pulled the cover off there where sign of fuel all over the the place. ?????:worship:

Ranger
04-26-06, 09:49 AM
The '93 & '94 Northstars had the fuel rail inside the manifold. As a result, it is subjected to manifold vacuum, thus no need for a vacuum line. Simply turn the ignition on to pressrize the fuel rail and look for fuel leaking from the FPR nipple. DO NOT CRANK THE ENGINE. If it starts in that configuration, it will run away unthrottled. If the FPR is leaking replace it.

94CaddyConcours
04-26-06, 01:05 PM
OK thank goodness.

94CaddyConcours
04-27-06, 05:52 PM
Well I turn on the ignition and no fuel leak. Also there is like I believe is fuel but it is dark as oil on the bottom inside my intake. Maybe its my Fuel Injector which I hope it isnt beace it would cost me 8 times more than a FPR.
Also there is a 2x4 black box connected to wire. What are they for? They look like there should be a hose connected to it.

Ranger should I put my cover back on and start it for and while and shut it down and take the cover off?
BTW the dealer discontinue the T30 bolts for the cover of 93-94

acfcrown
04-27-06, 05:54 PM
Ranger Please I Still Can't Fix This - My 96 Deville Fpr Is Not Bad - I Tested It , It Was Fine Car Still Poor Starter But Runs Like A Watch Rest Of Day . Fuel Filter Maybe??? Im Desperate Nay Suggestions Will Be Appreciated Thanks

Ranger
04-28-06, 10:25 AM
Well I turn on the ignition and no fuel leak. Also there is like I believe is fuel but it is dark as oil on the bottom inside my intake. Maybe its my Fuel Injector which I hope it isnt beace it would cost me 8 times more than a FPR.
Also there is a 2x4 black box connected to wire. What are they for? They look like there should be a hose connected to it.

Ranger should I put my cover back on and start it for and while and shut it down and take the cover off?
BTW the dealer discontinue the T30 bolts for the cover of 93-94
Remember, the PCV pulls crankcase gasses into the manifold and burns them. When you shut down, those gasses settle in the manifold. I suspect that is what you are seeing. Perfectly normal and it takes years to accumulate. Wipe it out and drive it for a few days. Then recheck it. I doubt you'll see any build up that soon.

Ranger
04-28-06, 10:27 AM
Ranger Please I Still Can't Fix This - My 96 Deville Fpr Is Not Bad - I Tested It , It Was Fine Car Still Poor Starter But Runs Like A Watch Rest Of Day . Fuel Filter Maybe??? Im Desperate Nay Suggestions Will Be Appreciated Thanks
Start with the basics. Get a fuel pressure guage on it and see what kind of fuel pressure you have, key on, engine off, then see what it is while cranking.

94CaddyConcours
04-28-06, 08:14 PM
I still get horrible MPG, I suspect it the injector.
Is it advisable to use carb cleaner in the intake manifold. Also while I'm here, if I get a 95 intake Manifold would that increase my hp up to 300? Would it be possible.
Also how do I test the FI.
Also to correct my previous post: The dealer discontinue the 4 bolts that hold the intake, But the 10 pieces of T30 with rubber are not. They are sold as kit only. They run about $70 for all 10 bolts with rubber while I need only 2 bolts w no rubber. The previous owner use a stainless steel and it was pain in the arse to remove it.
I didnt get to look for the drain plug for the radiator yet can you also point it out?

acfcrown
05-06-06, 06:24 AM
Ranger -you Wont't Beleive This My Deville 96 Runs Like A Top . The Problem Disappeared Starts Right Up Anytime I Guess It Was A Tank Of Bad Gas . As Soon As I Ran Real Low And Filled Up Again It Went Away.. Thanks For Your Help P.s. I Did Put In A Bottle Of Lucas Fuel Injection Cleaner When The Problem Started - This May Or May Not Have Helped But It's Good Stuff As I've Used It Before With Good Results

acfcrown
05-12-06, 09:11 AM
So Much For All Is Well ! After A Full Tank Of Super She Was Running Like A Top - Heavy Rain Last Night - Now She Got Two Blocks , Stalled And Won't Restart - Sounds Like Not Getting Gas
I'm Guessing It's The Fuel Pump . Is Fuel Pump In Tank? Any Idea What This Will Cost Me ? Thanks Again

Ranger
05-12-06, 04:43 PM
Yes, pump is in the tank.

acfcrown
07-09-06, 10:55 PM
ranger can you help??? now ive got a new problem low oil pressure light and chime go off occassionally stop engine message comes on .. then goes away . im guessing bad op switch , right? by the way oil is full and car runs great + no noise at all

Ranger
07-09-06, 11:12 PM
ranger can you help??? now ive got a new problem low oil pressure light and chime go off occassionally stop engine message comes on .. then goes away . im guessing bad op switch , right? by the way oil is full and car runs great + no noise at all
This section is for "Tech Tips". Please post questions in the proper section (Northstar).

eurumbaev
07-18-06, 10:27 AM
Great post. I seem to be having an opposite problem. My '94 Eldorado, 168k, has been having difficulty starting in the morning after sitting overnight, but once started, throughout the day starts on the dot. It seemed to be progressing worse and worse, untill today I wasn't able to start at all!:confused: Is it possible that a bad FPR might be causing this type of problem as well(even thought the symptom seem opposite), or would it be more likely the fuel pump? Any suggestions would be appreciated. Thanks!

chickenrob
07-18-06, 06:49 PM
sweeto! Just changed mine out, it was really bad, gas was spurting out the vacuum connection. I was having trouble starting not only hot but also cold (but it was better in the winter for whatever reason). A word of caution, the car did backfire WHEN I was checking the fpr, scared the crap out of me! This car sounds like a firecracker when it backfires, once I was driving some friends to camp and I acually asked them if they had firecrackers in their luggage we didn't know what the sound was. Also, I did attempt to releive the fule pressure, and I thought I had (some gas squirted out of the pressure release valve) but when I poped off the fpr, a miniature eruption of gas occured that also caught me off guard. The car was also sputtering a lot when first started, and this seems to have helped this too. Thanks for the great post!

Ranger
07-19-06, 03:55 PM
Great post. I seem to be having an opposite problem. My '94 Eldorado, 168k, has been having difficulty starting in the morning after sitting overnight, but once started, throughout the day starts on the dot. It seemed to be progressing worse and worse, untill today I wasn't able to start at all!:confused: Is it possible that a bad FPR might be causing this type of problem as well(even thought the symptom seem opposite), or would it be more likely the fuel pump? Any suggestions would be appreciated. Thanks!
I would suspect the fuel pump. Put a guage on the fuel rail and get a fuel pressure reading.

SkarTisu
07-27-06, 12:42 AM
Is there a special trick to getting at the fastening bolt that attaches the FPR to the bracket on the 4.9's? This has to be the DUMBEST design I've ever seen for hanging a part! It looks like I may have to pull the fuel rail, but the FSM doesn't describe the procedure from what I can find!

Frustrating! I really don't want to pay someone else to do this since the part itself is simple, and easy to see.

Thanks for any insight!

100
08-01-06, 02:14 PM
Is there a special trick to getting at the fastening bolt that attaches the FPR to the bracket on the 4.9's? This has to be the DUMBEST design I've ever seen for hanging a part! It looks like I may have to pull the fuel rail, but the FSM doesn't describe the procedure from what I can find!

Frustrating! I really don't want to pay someone else to do this since the part itself is simple, and easy to see.

Thanks for any insight!

I agree with you that it is a dumb design, but you do not need to remove the rail to replace the FPR. I did lift the rail when I did it first time (2 yrs ago). But now I know how to do it without lifting the rail. I used a torx (I forgot the right size, I think it is the same as that holding the fuel rail near the inlet and outlet) bit and a small wrench to turn. There is enough space to stick a torx bit there. Not too bad.

Yes, the aftermarket FPR didn't last long, only for 2 yrs and started leak! Now I installed one from ACDelco.

SkarTisu
08-01-06, 05:33 PM
The bolt fastening the FPR to the rail is a torx? What size?

I could see how you could get a small torx bit in there. Clever! :thumbsup:

100
08-01-06, 10:00 PM
Yes, on my 95 SDV with a 4.9, it is a torx. Unfortunately, I do not remember the right size. But as I said, the torx holding the fuel rail inlet and outlet on the engine is the same torx that is facing up, so you can easily verify the size of the torx bit there and stick the same bit under the FPR.

Good luck.

SkarTisu
08-02-06, 09:44 AM
Very good! Thanks for the tip....I'll let you know how it goes once I've tried it.

Gearheaad43
11-29-06, 06:36 PM
I changed out the FPR on the 97 STS..... Took a total of about 10 minutes... Easy as PIE!!! .. Wow!! I wish other GM cars were that easy!! LOL... The FPR I used was a GP Sorensen P/N 800-319, manufactured by Standard Motor Products, Inc.

Noticed a bit more power on tap!!! And no fuel smell "UGH" in the cabin.. YES!!

SkarTisu
12-27-06, 12:49 AM
Finally got mine swapped out. Here are some tricks I learned along the way.

- FPR location on the 4.9s is between the distributor and the throttle body. You have to remove the airbox to see it
- Remove the distributor cap AND rotor to get an unobstructed shot at the FPR fixing screw. I found it easier to mark all the plug wires, remove those, as well as the white connector on the distributor cap so I could fully move it out of the way
- The correct Torx key size for the fixing screw is a T27
- Using a Torx L-key, not a Torx bit, was the winning combination. I couldn't get a Torx bit secure on the screw to turn it
- Don't forget to fish the o-ring out of the old FPR and transfer it to the new one. Starting the car without that o-ring was a BIG (but not flaming) surprise!
- Even though you released fuel system pressure before disconnecting the old FPR (RIGHT?!) you'll still get fuel spillage out of the rail when you remove the FPR. Put that cigarette out first! Also, put something underneath the FPR to catch the fuel that will spill out. I'd guess that a tablespoon of fuel leaked out on mine.

I'm very pleased with the results. I haven't had a chance to test a "heat soaked" start yet, which was a problem before, but driveability especially at very light throttle application is much better. She pulls away from a stop smoothly now instead of a slight lurch and stumble. Fuel mileage appears to be improved, but I'll need to drive a whole tank to be sure. I think I got some power back (I should have anyway) but it's not a night-and-day difference. She jumps when you put the coals to her, though!

97Concours1
09-26-07, 12:45 AM
I just thought I'd let everyone know about a problem that I had that could be common on other cars. I pulled the vac line off of the FPR (fuel pressure reg) to check for gas coming out of it. No gas (good), but I also noticed there was no vacuum in the line either. I pulled the short little vacuum line off the intake and it was clear. I tried to poke a wire through the intake manifold nipple and couldn't even force it though. I finally took the intake completely off to see what was going on. I took the throttle body off and found a 1/4 inch of built up nasty carbon all over the back of the throttle plate and inside the intake. This also covered the vacuum port for the fuel pressure regulator. It actually took a drill to get it opened up, even after I scraped all the carbon off the inside!

This vacuum line is important for proper fuel mixture. If it is clogged, fuel mileage could suffer and the engine could run lean or rich causing other problems. My car ran better instantly after fixing this.

porkfarm
09-26-07, 08:18 AM
Glad to hear your ride is doing better. This is one of the reasons why I use seafoam every now and then. I try my best not to get the black build up on any intake part. Started with my Jetta TDI, those things can close up with 75K on the clock, but you can bypass the EGR with VAGCOM.

JimD
09-26-07, 09:23 AM
Great catch. This one should be moved to the Tech Tips forum.

Ranger
09-26-07, 12:01 PM
This is why it is important to clean the TB once a year.

I'll merge this thread with the FPR thread in the Tech Tips section.

RiZzLe7
01-07-10, 10:18 PM
how do u check fpr on 92 deville?

behind-bars
01-08-10, 12:17 AM
how do u check fpr on 92 deville?

Read the first posts all the way back on page one. The principal is the same on the 92 as it is on the northstars in the first post. Only different is that on the 4.9s in the 92 the FPR vacuum hose comes out the side, not the top.

If you remove the air filter housing you will see a small brass valve with a small hose (about 3 inches long) coming out at a 90 degree angle. Just pull that hose off the nipple and look for leakage.

arctic_man
06-30-11, 02:01 PM
I just thought I would chime in and note that my 99 Deville had a faulty FPR, but it was not leaking fuel when I did the vacuum test. I did have all the symptoms: Surging when idling - seemed like the car would drive itself. Poor start when warm, and a couple others I cannot remember. Put up with these issues for 2 years, as it was on and off at first, and cleaning the TB seemed to help, but eventually I spent a few days of research and thought I would give it a shot.

Replaced the FPR and it has never been better.

my .02 cents.

Bogdan
09-30-13, 11:11 PM
What happened with all the pictures?

rayjuswa
03-18-14, 12:00 AM
What do I have to do to see the photos?

Submariner409
03-23-14, 04:48 PM
Many members go back and purge old pictures from the forums - Look in the proper engine forum or the specific vehicle model forums.

If you reduce the file size and upload pictures from an online service they should remain forever; CF has a 20 mb limit on attachment filesize, thus the need to occasionally make more room .......

For you, this might work - http://lmgtfy.com/?q=cadillac+forums+1995+deville+fuel+pressure+regu lator&l=1

Ranger
03-23-14, 09:20 PM
Picture reattached.

Ranger
03-28-14, 02:47 PM
DO NOT touch the line with the yellow arrow. :tisk: See you other thread. http://www.cadillacforums.com/forums/northstar-engines-system-technical-discussion/479298-1997-sts-high-rpm-just-during-2.html#post12186689