Hot start...but not the FPR!
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 3 1 2 3 LastLast
Results 1 to 15 of 31
Northstar Engines and System Technical Discussion Discussion, Hot start...but not the FPR! in Cadillac Engine Technical Discussion; If you have been tracking my posts I have a hot start problem when my car's been parked for at ...
  1. #1
    weister42 is offline Cadillac Owners Enthusiast
    Automobile(s): 1998 Cadillac Deville Sedan
    Join Date
    Feb 2005
    Posts
    897

    Hot start...but not the FPR!

    If you have been tracking my posts I have a hot start problem when my car's been parked for at least half an hour after the engine warms up. First I thought it was my stereo and I ripped it all out, then I had a shop run a cleaning agent to clean my fuel injectors, replaced the fuel pump relay & filter, plugs & wires are 8 months old and the car runs perfect when it's running. I replaced the FPR this weekend and the problem did not improve a bit (60 dollars down the drain ). One thing I noticed when I removed the old FPR was a coat of very dark red oily substance under the FPR and probably all around whatever else that's connected to the underside of the FPR, my friend and I couldn't figure out what it is but I don't think it should be there (should be just fuel).

    So, I'm confused. I'm wasting my money. WTF???

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    zonie77 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 ETC,97 STS
    Join Date
    Sep 2003
    Location
    Arizona
    Posts
    3,531

    Re: Hot start...but not the FPR!

    The suggestion was to buy a vacuum tester and test it before replacing it.

    I would test the fuel pressure next.

  4. #3
    weister42 is offline Cadillac Owners Enthusiast
    Automobile(s): 1998 Cadillac Deville Sedan
    Join Date
    Feb 2005
    Posts
    897

    Re: Hot start...but not the FPR!

    Actually my mechanic told me the FPR is fine...he followed the vaccum test on this forum but I just want to eliminate all the possible faulty parts. Fuel pressure comes out to be 42psi. Again the car drives perfect when it's running.


  5. #4
    weister42 is offline Cadillac Owners Enthusiast
    Automobile(s): 1998 Cadillac Deville Sedan
    Join Date
    Feb 2005
    Posts
    897

    Re: Hot start...but not the FPR!

    However I do have one question...what are those wires running into the passenger side of the engine compartment? It's a black plastic wire organizer and that's where my power wire for the stereo goes through (wires were the only component I didn't remove when I took everything out). I trimmed the plastic part so the thick wires can go through and it's really close to the factory wires.

  6. #5
    eldorado1 is offline Cadillac Owners Connoisseur
    Join Date
    Feb 2004
    Location
    FL
    Posts
    2,250

    Re: Hot start...but not the FPR!

    Could you explain in more detail what it's doing?

    When you start it, it turns over... does it try to fire? Do you hear a couple puffs? Does it just crank? How long does it take until it does fire up? Does it start up if you let it cool down? (is that the only way it will start?)

    What happens when you push the pedal down when you try to start it? Does it start easier? Not effect it at all?

  7. #6
    zonie77 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 ETC,97 STS
    Join Date
    Sep 2003
    Location
    Arizona
    Posts
    3,531

    Re: Hot start...but not the FPR!

    The wires go to the computer, it's behind/below the glove box.

  8. #7
    CadillacSTS42005's Avatar
    CadillacSTS42005 is offline Banned
    Automobile(s): 2005 STS4 1SG: GM Acc Lights, Corsa, Platnium Grille, Volant
    Join Date
    Oct 2005
    Posts
    15,992

    Re: Hot start...but not the FPR!

    I had the same problem with my Trans AM but thats a crossfire lol. (AKA designed by those who had developed the caddy 4 6 8 motor so you kno the set up is shit) i had to replace the ECM worked fine ever since

  9. #8
    weister42 is offline Cadillac Owners Enthusiast
    Automobile(s): 1998 Cadillac Deville Sedan
    Join Date
    Feb 2005
    Posts
    897

    Re: Hot start...but not the FPR!

    It takes about 3~5 seconds to start when it doesn't want to, starter spins rapidly and everything is normal, car drives perfect when it's on.

    My car does start better when I press on the gas pedal (at times when it doesn't start right away), so does this mean I have a fuel leak somewhere?

  10. #9
    eldorado1 is offline Cadillac Owners Connoisseur
    Join Date
    Feb 2004
    Location
    FL
    Posts
    2,250

    Re: Hot start...but not the FPR!

    So it doesn't even try to fire?

    And it only happens when it's hot? No stalling or hesitation or anything when it's running?

  11. #10
    zonie77 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 ETC,97 STS
    Join Date
    Sep 2003
    Location
    Arizona
    Posts
    3,531

    Re: Hot start...but not the FPR!

    I'd hook up a fuel pressure gauge and check it every time I started it. It would be nice to have it sticking out of the hood where you could easily see it.

    The check ball in the fuel pump could be leaking and letting the fuel drain back to the tank. I realize this should be true on cold starts also but this is the next step I'd take. If it showed 40+ while no start it would eliminate pump.

  12. #11
    coppertop's Avatar
    coppertop is offline Cadillac Owners Fanatic
    Automobile(s): 1995 Cadillac STS
    Join Date
    May 2005
    Location
    Toronto, Canada
    Age
    42
    Posts
    152

    Re: Hot start...but not the FPR!

    I thought the fuel pressure was not to be under 45- 50 PSI? Is that just pre starting the motor? I was ready to change the fuel pump because my car running is at 35 PSI.

  13. #12
    zonie77 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 ETC,97 STS
    Join Date
    Sep 2003
    Location
    Arizona
    Posts
    3,531

    Re: Hot start...but not the FPR!

    I said 40 without checking. Don't take that for gospel.


    to Weister, check what the pressure should be. If it's even a few pounds low it can give hard start problems.

  14. #13
    eldorado1 is offline Cadillac Owners Connoisseur
    Join Date
    Feb 2004
    Location
    FL
    Posts
    2,250

    Re: Hot start...but not the FPR!

    Quote Originally Posted by coppertop
    I thought the fuel pressure was not to be under 45- 50 PSI? Is that just pre starting the motor? I was ready to change the fuel pump because my car running is at 35 PSI.
    Fuel pressure should be at least 40psi idling, and it should rise 5psi if you disconnect the vacuum line to the FPR. If that is not the case, you need to investigate and/or replace the fuel filter, FPR, or fuel pump.

  15. #14
    El Dobro's Avatar
    El Dobro is offline Cadillac Owners Connoisseur
    Join Date
    Sep 2003
    Posts
    1,471

    Re: Hot start...but not the FPR!

    I've had a similar problem with my 98 SLS. The car will not start after approx. 5 min. when hot. It wil start before and after that time period and it doesn't do it all the time. Everything checks out. Now, to play it safe, I depress the throttle slightly to ensure that it starts when I fill up for gas.

  16. #15
    weister42 is offline Cadillac Owners Enthusiast
    Automobile(s): 1998 Cadillac Deville Sedan
    Join Date
    Feb 2005
    Posts
    897

    Re: Hot start...but not the FPR!

    My fuel pressure is at 42psi so it's normal, I now have to tap the gas pedal halfway down to get the car to start. My car does the long cranks mostly when the engine is warm but sometimes cold. I'm guessing there might be some sort of gas leak that drained the gas out so it takes time for the fuel pump to refill the gas line?

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting