96 3.8 Camaro dies after driving ~3 hours - F-Body Online

IndyTruck · 08-19-2007, 05:08 PM

Hey y'all--

My kid has a 96 Camaro 3.8 5-speed, all stock except a Flowmaster. I bought the car as a non-running project (it sat for several years) and we just got it on the road Monday.

The car has 77K miles. New parts before getting it on the road include:
plugs (AC Delco Rapidfire/Irridium/whatever/$4 each)
wires (MSD)
front O2 sensors (Bosch)
fuel pump - complete assembly w/ pickup & sender (Carter iirc)
Purolator fuel filter
drained gas tank, filled with new gas

New parts installed trying to fix the problem:
TPS (Delco)

New parts being installed today:
Water pump (Delco)
195* thermostat (Delco)
Radiator cap (Delco)
Radiator hoses
Heater hoses

It runs perfectly, until we've been driving ~3 hours, then it won't accept any throttle (push the gas, doesn't rev), runs crappy, then dies. After turning off the key and sitting for a minute, it starts right up. It may run fine for 15 minutes or 15 seconds, then does it all over again. I had to restart it probably a dozen times monday night trying to get home, and when it ran, the idle speed was ~2200 RPM.

The ~3 hours driving is mostly around town, running errands, a little bit of highway, just making sure the car is OK and teaching him how to drive a stick. Like I said, the car runs flawlessly, right up until it quits. The gages read normal. It shows P0122 on the code reader, which is TPS.

I replaced the TPS with a new AC Delco Tuesday, and went for another long drive. It quit again after ~3 hours the same way. Required several re-starts to get it home, but this time the idle speed was normal. Again, it shows P0122, but I'm thinking that disconnecting various sensors (including the TPS) while trying to find the problem may be falsely setting that code. But that's the only code it has.

I only had time to drive about 90 minutes Wednesday night. Nothing went wrong. Had a fuel pressure gage taped to the cowl and, when running WOT thru the gears, the fuel pressure dropped to ~18 midway thru 3rd. I’ve got a new Delco fuel filter for it; that goes in today. I plan to install a new fuel pump relay. I’ve been told I should have bought an AC Delco fuel pump!

My kid drove the car a bit on Thursday with no problem again.

I probably should have dropped the tank and had it cleaned, but instead I used the trapdoor method of fuel pump replacement. I'll open up the trap door again and look at the fuel strainer, and probably get the tank cleaned once we run the gas out of it.

I haven't found the fuel pressure regulator either. The Haynes manual has photos of a 3.4 and an LT1, but no 3.8. Where is it? At this point, I’m thinking the FP is regulated by the computer via variable pump voltage…

The cooling system wasn’t maintained, and is full of sludge. The radiator cleaner I poured in seems to have cleared out the crud that was holding the water in the water pump, and now it leaks freely. I got a new water pump, radiator cap and 195* thermostat (all Delco), plus new radiator hoses and heater hoses.

The temp gage shows 180* when warm, but the old thermostat was 195* too, so I gotta figure that out...

I haven’t found any wiring that is worn thru or eaten by rodents. Will keep looking.

Someone suggested a new intake air temp sensor. Other suggestions were a bad gas cap, and to spray “Component Cooler” on electronic items when the problem occurs.

After I put the car back together today, I’ll drive it until it quits again. I’ll have the fuel pressure gage taped on, so I can tell if I have a fuel problem. I’ll take off the gas cap and see if it fixes the problem. If not, I’ll disconnect the intake air temp sensor and drive it again. If it still quits, I’ll disconnect the MAF and see how it does.

I’m REALLY HOPING someone here has experienced this and fixed it!!

What do y’all think?

thanks!
kevin

SpecialK · 08-19-2007, 11:44 PM

Fuel regulator most likely needs replaced. I've had the problem on my s-10 work truck.
Though it might also be a EGR valve that needs to be replaced. When it does stall is it only during partial throttle? Have you ever just ran it up to a rather high cruising speed with your foot in it to see if that fixes the problem for the time being? If that does fix the problem it could still be either.

Also, a 195 thermostat is excessively high and the only reason GM put that in the car was so in the winter months the heater is always burn your feet hot. Drop down to a 180 - 170 and the car will run even smoother, and the heater will still be plenty warm, unless you live in Canada or Maine.

Also if that thing's been sitting in storage for years liek you say it has I would suggest some sea foam in the tank and crankcase, jsut make sure you are ready to change the oil the same day when you put the Seafoam in with the engine oil. Another place to put some woudl be in the brake booster vacume line. Blow out varnish and carbon in the top end of your engine, jsut let it sit for about an hour instead of the recommended 30 min that way it has time to really eat at the crap that's surely in there.

Rocket 442 · 08-20-2007, 07:50 AM

It could be the EGR, but I doubt it. I've been running my 95 3.4 with the EGR valve messed up for over a year and a half. Only thing that really happens is when you let off the gas the check engine soon light blips on and stays on until you shut off the car.

IndyTruck · 08-20-2007, 11:07 PM

I have successfully duplicated the problem while having a fuel pressure gage attached! The fuel pressure drops to ~10. This is with the rusty gas tank nearly full, a new AC fuel filter, the Carter fuel pump, and the original relay. It happened while accelerating onto I-75;

I shut it off on a roll, coasted in the shoulder for a bit, restarted and was able to keep the car running with a feather foot in 5th gear. After 5 minutes or so, the pressure started creeping back up. When it hit 20, the car ran pretty well, and eventually returned to normal.

So the plan is:

1) new tank (or possibly clean old tank) and AC Delco filter- if that doesn't help,
2) new relay
3) new cap
4) new AC Delco pump

What's that gas tank site? Gastank.com or something? Anybody buy there?

Thanks y'all!!

SpecialK · 08-22-2007, 12:02 AM

I dunno man Carter pumps are pretty nice and it being that new there's no reason it shouldn't be able to provide sufficient fuel. I'm still gonna say it's the regulator thats' giving you fits, being coated with varnish most likely it'll pop open then wont close enough until all fuel pressure drops form the system. Because like you say it just dies and then as soon as you turn the key it runs fine and the pressure builds.

IndyTruck · 08-22-2007, 07:34 AM

Where is the regulator? The Haynes manual doesn't show it and I can't find it!

thanks!!
kevin

SpecialK · 08-23-2007, 04:46 PM

Now It'd be really handy if we had Phate chime in here because I honestly can't remember myself.

Phate · 08-24-2007, 03:15 PM

Sorry for the late arrival in the thread fellas, i've been rather busy as of late and havnt been able to visit the site much.

Anyway, the regulator is part of the fuel pump. So you would have to replace the pump as well as the regulator. It does sound like the regulator in my oppinion also.

Now, if you've never done a fuel pump on a 4th gen before, give yourself half a day or more depending on your personal mechanical skill. I've dropped the tank on my camaro numerous times, and it still takes me a good 3 hours to do it. And please,while we are on the subject, do not cut a hole in the floorboard to get to the pump as many people do.

IndyTruck · 08-24-2007, 06:21 PM

Well, I already cut the hole and replaced the pump with a new Carter. When I continued having problems, it was nice to be able to inspect the pump without dropping the tank.

However, I need a new tank anyway. I'm going to replace it, and if the problem doesn't go away, I'll be glad to have that hole in the floor so I can replace the pump again.

Thanks for the tech on the regulator!!

SpecialK · 08-25-2007, 01:35 AM

Well if your going to replace the tank get one of the plastic ones so it doesn't rust again.