: Hard starting.



carguy
11-23-04, 08:50 AM
I have a 96 ETC. The car starts hard (takes quite a few cranks of the starter), and then has a rough and fluctuating idle, and hesitates. After the vehicle warms up it runs fine, but on shutdown starts hard again.
Plug wires, plugs, fuel filter have been recently replaced. I haven't checked anything as yet, ie codes or fuel pressure.

Any ideas?

eldorado1
11-23-04, 01:26 PM
Check FPR for leaks at the vacuum hose, and check the fuel pressure key on, engine off (after fuel pump primes). It should hold steady around 40psi or so, and not drop a significant amount in any time.

carguy
11-23-04, 05:22 PM
It may be this or the pump. I removed the beauty cover and pressed on the schrader valve just after the engine was shut off after starting and barely any fuel came out. I will run the fuel pressure test tonight. The car has about 71,500 miles on it.

Thanks.

96 STS
11-23-04, 08:20 PM
Hi carguy! Just my .02 cents, but like eldorado1 mentioned, check to make sure that your pump is priming the system when you first turn the key. Should run for 2 seconds to prime the system for startup, then shut off. You should be able to hear this if your car is parked in a pretty quiet area, like a garage or no traffic or other noise around you.

As my name implies, I've got a '96 Seville & had the same experience this weekend. My car started up fine in the garage but went dead right after I pulled out. Luckily it happened there & not out on the road.

I did the same thing with the schrader valve & got the same results. I'd suggest what I read here on the forum & kind of trace the system back. Meaning if you get no fuel at the valve, then disconnect the fuel line at the filter & see if any pumps out there. Could be a clogged filter. If nothing pumps out before the filter then it probably IS the pump relay or the pump.

As I learned thru my service manual, the PCM is programmed to prime for 2 seconds then will not start the pump again until sufficient ignition parameters are met. I assume this means that the engine is running. Because of this I found it kind of hard to verify if power WAS going to the pump or not. Of course I did my repair by myself. Perhaps you could get someone to help you to verify if power is getting to the pump during this 2 second prime time. On mine you could access the pumps electrical plug under the car just behind the tank.

I don't know if an ETC tank & pump are the same as a Seville, but if they are I have a bit of advise from my repair experience this weekend.

If you have to drop the tank to get to the pump, you DON'T have to remove the filler pipes or completely remove the tank. I was able to get access to my pump by simply putting the car on stands as high as I could (all 4 corners), then unbolting the the 4 tank support bolts & dropping the front of the tank while supporting the rear of the tank with blocks (or something so as not to strain the filler pipes). I then had more than enough room/clearance to remove the pump.

Somehow mine ended up having shorted/fused wires with the fuel level sender. It all made since when I found it because my fuel gauge had been acting crazy for a few months (1 second it said empty, the next second is said 1/2 tank). I ended up deciding to just repair the wiring & reinstall the pump. So far so good. I'm still a bit curious & worried about what fused these wires together to begin with, but I don't really have the $$$'s right now for a new pump. So I took a chance & repaired the pump & reinstalled.

Again, if you think you'll need to remove your pump & the ETC is the same tank setup as a Seville, don't worry about disconnecting the filler pipes. Trust me, it's a B*tch!! I DID have to once in order to gain clearance to replace some brake pipes & hope that I never have to do that again.

Anyway, good luck with your situation & keep us posted.

Cheers,
96 STS

mcowden
11-23-04, 08:59 PM
That's great info, STS96, thanks very much for posting... I'm headed down the troubleshooting path that's leading closer and closer to the pump on my 96 SLS, so this may save me significant time and effort very soon. Appreciate the heads-up! I'm stumped as to what caused your short. Maybe corrosion and some arcing? Without having seen the harness going into the tank I couldn't speculate inside the ballpark...

carguy
11-24-04, 09:07 AM
My starting problem is intermittent. Starts fine in the morning after it has sat overnight.

I checked the FP
It was 45 psi at prime and 45 psi running. However, the vehicle was starting fine at the time so I am going to try it again today when I think it will have it's problem. I will report back on here today.

Oh, and as I stated above I just recently replaced the filter. The old one was in good shape too (not plugged)

carguy
11-24-04, 10:59 AM
I just checked it again and was starting hard. The fuel pressure was the same as above and went over 50 psi with the vacuum line to the regulator disconnected.

I don't think the engine was flooded so it may now be an ignition problem.
Crank position sensor? cam position sensor?

Any other ideas?

Ranger
11-24-04, 11:43 AM
Hard hot starts usually indicate a rich condition. Leaking FPR or injector(s).

carguy
11-24-04, 12:07 PM
I will look into that. Wouldn't that also cause a drivability issue too?

eldorado1
11-24-04, 03:00 PM
Okay, when it primed the fuel pump, and went to 45psi, did it start dropping quickly? Or did it stay at roughly 45psi for a good 10 minutes or more? Just from the initial prime, I can stay above 40psi for 20 minutes to a half hour.

Ranger
11-24-04, 11:11 PM
I will look into that. Wouldn't that also cause a drivability issue too?
I think it might depend on how bad it is leaking. Might not be noticable.

carguy
11-29-04, 01:28 PM
I will check to see how long the pressure stays up, but I don't think that this is it. At start there is plenty of pressure either way.

I forgot to mention that the car also backfires through the intake sometimes, ONLY WHEN TRYING TO START.

I am now suspecting an electrical issue, such as a crank or cam sensor.

I checked the codes and there is only one, which is a History code.

carguy
12-04-04, 04:05 PM
Fuel pressure stays up for quite some time...
Fuel injectors are not pulsing during cranking.


Cam position sensor??

carguy
12-06-04, 11:48 AM
Hmmmm..where is the cam sensor. I looked over all the covers and didn't see any wires going in any. Is everything under the cam cover? Do I have to take it off to access the sensor?

eldorado1
12-06-04, 11:58 AM
Hmmmm..where is the cam sensor. I looked over all the covers and didn't see any wires going in any. Is everything under the cam cover? Do I have to take it off to access the sensor?

Passenger side, front (as in pulley-side) of the *rear* head. Don't have to take anything off afaik... You *might* have to go in through the passenger wheel well, not sure how much clearance you have from up top.

carguy
12-06-04, 02:19 PM
O.k. thanks. It is probably lower than I thought it was.
I don't think the car is getting enough fuel to start it. Once it is running, it is fine...

I thought that if the sensor was bad it may do this as it may just be weak instead of failed.

oldgamer
12-06-04, 06:44 PM
May be I wrong, but I think it's getting enough fuel, cause backfire is a simptom of "too rich fuel mix" condition. Check "Leaking FPR or injector(s)." like Ranger said.

eldorado1
12-06-04, 11:30 PM
Just something else to consider...

If your IAC died when it was ratcheted all the way in, this could also be possible. It would basically be like cutting off the air supply to the engine, and make it very difficult to start (cold or warm). It would also cause a rough idle until it warms up, and possibly cause it to stall when doing various things.

I still don't particularly think a cam sensor would do this. If it were intermittant like that, it would be cutting out any time, not just at startup. Well... I guess if it was getting weak, and couldn't do much <500rpm...

wait - rereading some of your posts, you say that the fuel injectors are not pulsing during cranking? Is this being checked with a noid light? (I hope?)

If this truely is the case, first thing's first, and you need to check for +12V at the ignition module during cranking.. actually during cranking it'll probably be like 8V.

Ranger
12-07-04, 12:19 AM
Just something else to consider...

If your IAC died when it was ratcheted all the way in, this could also be possible. It would basically be like cutting off the air supply to the engine, and make it very difficult to start (cold or warm). It would also cause a rough idle until it warms up, and possibly cause it to stall when doing various things.


I don't think the Northstar has an ISC motor like the 4.9. I believe it is an ISC valve somewhat like the EGR pintle valve that opens a bypass circuit which allows idle air to bypass the throttle plate. point being that there is no ratcheting or throttle plate movement for idle. Now that's not to say that the ISC valve can't be acting up.

cart69
12-07-04, 09:23 AM
speaking of the isc where is it located? my seville has a high idle and i was told that isc might be gummed up to clean it and the throttle body then pull the bat cable for 30 seconds so the comp relearns the idle adjustments and see if the prob goes away

eldorado1
12-07-04, 01:05 PM
I don't think the Northstar has an ISC motor like the 4.9. I believe it is an ISC valve somewhat like the EGR pintle valve that opens a bypass circuit which allows idle air to bypass the throttle plate. point being that there is no ratcheting or throttle plate movement for idle. Now that's not to say that the ISC valve can't be acting up.

That is correct... But the 93-94's did have an idle air control motor that actuated the throttle itself. The 95+'s (like carguy's) have a stepper motor that opens and closes a bypass as you mentioned above. If it got gummed up (due to old age, or stripped it's teeth, or whatever), it could have failed fully extended, basically choking the engine. It would be very difficult to start in this condition, and would run poorly until it warmed up. And cause all those problems I mentioned above. The IAC on 95+'s is located on the throttle body being held on with 2 screws, and has a 4 pin connector.

Looking at this picture,
http://i3.ebayimg.com/03/i/02/55/e5/0e_1.JPG
it's the top silver cylinder with the black connector end.

carguy
12-07-04, 02:21 PM
I already checked for a leaking unit and they don't seem to be leaking. Pressure does drop over about 15 min with the vehicle off. I do believe that this system will bleed pressure eventually though.
One odd thing is that the low level oil light (the level is not low) started coming on at the same time this happened. I had some theories as to a connection, but I don't believe they are valid.


I still don't particularly think a cam sensor would do this. If it were intermittant like that, it would be cutting out any time, not just at startup. Well... I guess if it was getting weak, and couldn't do much <500rpm...

That is what I was thinking.


wait - rereading some of your posts, you say that the fuel injectors are not pulsing during cranking? Is this being checked with a noid light? (I hope?)

No, I checked them for output, I didn't have time to figure out something to rig up which would be able to work while I cranked the car. Nobody was available to help.



If it got gummed up (due to old age, or stripped it's teeth, or whatever), it could have failed fully extended, basically choking the engine. It would be very difficult to start in this condition, and would run poorly until it warmed up. And cause all those problems I mentioned above.

I know that it is not gummed up as I serviced it a while back which involved cleaning the rubber piston, spring, and piston seat in the manifold. It could be defective , but I would think that this would throw a code for being out of range, if the ECU could not control it properly.

carguy
12-07-04, 02:30 PM
Please also see EGR cleaning thread. I am not sure if mine is functioning properly. This may also cause problems.

Ranger
12-07-04, 06:48 PM
speaking of the isc where is it located? my seville has a high idle and i was told that isc might be gummed up to clean it and the throttle body then pull the bat cable for 30 seconds so the comp relearns the idle adjustments and see if the prob goes away
I think the ISC valve is located just above the throttle position sensor.

carguy
12-08-04, 11:01 AM
Yes, this unit is above the TPS.