02 SL1 Weird Starting

[joelawrence]

I have an '02 SL1 which usually starts fine cold. After running it will usually restart, but after running then sitting for an hour or so it will crank 5-15 seconds before starting. The engine is definitely turning at this point (had someone check). The problem is somewhat unpredictable. Once started it runs very well.

There are about 65k miles on the car, so I wouldn't think it's the fuel filter. Setting the car to 'run' for a few seconds before cranking (to get fuel moving) does not seem to help.

I tried replacing the ECTS but there was no change and the temp gauge acts normally. It has fresh plugs, wires, and air filter. There are no codes. There is no gas smell or other problem with the car that I can tell.

Any ideas? Thanks for the help.

[joelawrence]

I just remembered that a few weeks back I got an SES and a P0133 (front O2 slow response) code, that went away. I ordered the front O2 sensor, but the light has been off for a couple weeks at least.

Could it be that a slightly bad O2 sensor is reading high/low and the car is getting the wrong mix? I assume the ECM ignores the sensor on a cold start since it would be out of range, but maybe a slightly warm engine puts the sensor in range enough that it is trusted but inaccurate?

Thoughts on this idea? I'll be able to replace the sensor in a day or two. I really can't think of anything else.

[fdryer]

Well, some maintenance may be needed; removing and cleaning the ignition control module and both ignition coils of corrosion, some dielectric grease on the plug boots, a fuel pressure check using the fuel rail's test valve to see actual pressure without guessing, and cleaning the throttle body. Autozone should be able to loan you a pressure gauge.

[joelawrence]

Thanks for the reply fdryer! I finally got a fuel pressure gauge. The running pressure is a bit high at 59 psi -- at least according to the Haynes book which says max should be 55 psi. The kicker though is that the pressure immediately drops to zero when the car is shut off. According to the book again, it seems that the pressure should mostly hold. I don't see or smell any fuel leaks. This sounds like a bad filter/regulator to me. Is that a good assumption?

[fdryer]

'97's are the only ones to have the faulty fuel pump check valve that drops pressure immediately when ignition is turned off. No one else has this problem in any model.

The pressure regulator would be one of several issues to suspect. If yours uses a vacuum line to regulate pressure, check the vacuum line for raw fuel - this would indicate a rupture in the diaphragm. Next might be a leaking injector from a clog keeping the pintle valve cracked open and leaking. Removing the fuel rail and injectors to lay out in the open and connected to power up would show which injector is leaking.

[mgordon1100]

I could be wrong here, but I think I had that pressure problem with my 02 SC1. The next time the OP knows that it's going to happen (slow starting), it wouldn't hurt to just turn the key to run for a few seconds before starting. You know, just to see. Like I said, I could be wrong. I've had this 01 for four years now, so memory could be fuzzy. In any case, it was an issue for me in either the 2002, or the 1998. Both of which, are not 1997's.

:edit:
Why? Because my memory just came back. My 1998 threw a differential pin. I had absolutely no idea what that meant, and was quoted about 4 grand for the rebuilt transmission job. That's when I got the 2002, and discovered this site. I knew I had to start figuring things out for myself with shop prices like that. It was definitely the 2002 that had the issue.

[joelawrence]

I bought the OE filter-regulator unit and had a mechanic install it (I'm a little skittish about opening the fuel line even though it looks like an easy job). It started great on a few outings, so it could be fixed. I'll post again if the problem returns after more starts are observed. Thanks for the input -- this is my first thread here as I just bought the car!

[joelawrence]

Three notes for future readers of this thread:
1) Unlike I stated above, I believe that the car's starting did improve slightly when turning the car to "run" for a couple seconds before cranking.
2) The mechanic said several cars displaying the same symptoms ended up having a bad fuel-pump check valve.
3) Replacing the combination fuel filter/regulator definitely fixed the problem on my Saturn.

I hope that will help everyone!

[mrbadwrench]

My 02 sl2 does the same thing and leaving at run/changing spark plugs/changing o2 sensor didn't help, where did you get the filter unit and how many hours did the mechanic charge for installation?

[joelawrence]

I bought the filter from my local Chevy dealer. The price was quite high, but after reading some other forums the aftermarket alternatives seem to be very hit-or-miss.

Luckily the unit is outside of the tank in an easily accessible spot. If you are comfortable with fuel-line work you can easily do it yourself (look for richpin06a's youtube video). My mechanic charged 1/2 hour labor. He knows I'm a student and may have given me a deal, but it really is a 1/2 hour job at a shop.

EDIT: FYI if you are looking for the OE part, GM seems to list it as the regulator with no mention of it being the filter.