Railroadman

Vacation is turning into a nightmare! I'll give a full post later but need a couple answers. We're in Amarillo with a sick Vette.

Problem: Car loses power, is obviously starving for fuel. Let off on the pedal and it will idle, put your foot down and it does nothing, or dies completely.

What I have done: Pulled line off fuel pump fitting, gas comes out like old faithful. NOT a bum fuel pump.

Changed both the factory fuel filter and the aux one I had added. No obvious crud in either and did not cure the problem. Again strong line pressure.

Used heat wrap around the canister in the exhaust right next to the fuel filter, and also around the filter itself. Wrapped aluminum foil around as much of the line as I can.

THIS IS A HEAT PROBLEM. When I shut it off and sat for 50 minutes with hood up it started up and drove normal for 25 miles. (Outside temp 102 degrees). Next time it died I put an ice pack on the ECM and it seemed to speed up the recovery.

QUESTIONS: Is the ECM normally heat sensitive? Does this suggest the ECM is failing? Am I correct that - assuming there IS fuel pressure in the line, it's the ECM that decides how much fuel the injectors get? While fuel is the issue I'm about of ideas on the fuel system itself and am thinking it's something else.

We're 1575 miles from home and thinking of aborting the trip and limping home at night. They're naturally calling for 100+ degrees daytimes.

I'll log back on tonight or tomorrow. Thanks for the help.

joeld

Wow, hate to hear this on your trip!
Even though you see fuel from the line, there could still be a problem with having enough pressure. Can you check with a gauge to rule this out?
I have not ever had a ECM problem due to heat, not saying it's not possible.
And yes, the ECM does control injector pulse.
When I hear heat related, I think of ignition module in distributor as one possible cause.

Joel

Frizlefrak

Don...borrow a fuel pressure gauge from Autozone. I'm betting your pump is failing when it heats up. It may be providing fuel, but not enough for it to run. Your symptoms are exactly what my 84 did when the fuel pump failed. Ran fine cool....10 miles later, wayyyy down on power. New fuel pump fixed it.

Also check the "pulsator" if you pull the pump. The hose between the pump and the hard metal fuel line on the sending unit.

I hope this is it.....easy repair, and back to more adventures. Wish you were in EPT....we'd have it fixed already.

Keep me posted.....

Frizlefrak

CRAP.....I wish it was two days ago....I'm off Fri and Sat....could have just taken my pickup and a trailer and brought it here, but I have to go back to work on Sunday and there's nobody that can cover me, and Amarillo is 8 hours each way.

If it's not an easy fix, let me know. I may be able to get a day off in the middle of the week or push comes to shove, next Thursday / Friday if you can hunker down that long.

QCVette

One more for testing fuel pressure.

I have had a couple fail and they acted similar to yours. Both still pumped, but low enough on pressure to cause problems.

On a 96 Impala SS it even acted the same with hot or after a cool down. I had to stop and wait a few times to let everything cool and then I could drive it another 10 or 20 miles at a time to limp it home. I am not sure of the reasons why it acted this way, but the symptoms seem the same as yours.

Good luck.

96 Vette CE

Don, is it throwing any codes? Any backfiring involved when you experience loss of power? Like Friz says it could be fuel pump related when pump gets hot. Also could be ICM when it gets hot.

Frizlefrak

Yep, we need to get a fuel pressure reading during a power loss event. I really believe this is a fuel delivery issue as you didn't mention it misfiring.

96GS#007

I highly doubt you have a calibrated eye that allows you to determine if the fuel is squirting out at 15psi or 40psi.

The ECM does determine how long the injectors fire, based on input from various sensors. The "how" depends on if you have a speed density car which uses a MAP sensor or a MAF sensor equipped car (they will have a MAP as well for backup).

What year car? Just checked your profile...1992 LT1.

No WAY would I drive at night like that. The last thing you need is for it to die completely in an area with no cell service or any other services.

Get a $25 fuel pressure gauge and report back on the pressure.

FWIW, there's been a rash of ICMs failing lately. The ICM is extremely heat sensitive when it's dying although it's typically an on/off switch vs what you describe.

corvetteronw

I have a spare ECM for my 91 that I bought as a spare. Will it work for the 92? I can overnight it to you if it will help. Just PM me. It is 11:20 PM here in Michigan and I am watching my Tigers battle against the Rangers in the 9th inning.
Good luck man!

Railroadman

Thanks for the support and advice guys. This forum is the best!

We went to hear the band we wanted to, it was 2 miles from the motel so no problem. I'm going to try to make it back to Clinton OK tomorrow, hopefully starting out early (yeah right, it's 2AM!)

If I get to Clinton there's an O'Riley's and I can probably get a pressure gauge there. And I actually am a member of Western Oklahoma Corvette Club so someone there may have one I can bum.

If ECM only controls the length of injector squirt...well, wait, I suppose if it does not allow a long enough shot it could starve.

Fuel pump is 3 years old but it sounds like that could be it altho my gut says no. The gauge will tell.

I'm going to sleep now. If it will get us 176 miles back to Clinton I'm in good shape. By the way, no backfiring.

Thanks to all, I'm too tired to mention each one of you but all the input IS appreciated.

Will have ice packs to set on the ECM tomorrow if it helps. And back at Clinton I DO have my FSM with me if I can get that far.

Midnight 85

I got my '85 in December and it drove just fine until the weather got up to 80 or above. When it was hot outside the car would drive fine for about a half hour or so then as I would pull up to a stop sign it would die and refuse to restart for a minute or two. Once it cooled down it would start & run fine a bit longer then start acting up again. Long story short, it was the ecm. Kep ice on it and if it keeps going until the ice is gone then it is most likely the ecm. Good luck, there is nothing worse than to have a vacation ruined by car trouble. Been there, done that.

mickey5

Had the same problem last year with my '90 L98. Run perfect for 100 miles...shut it off for 20 minutes and it wouldn't start. Kept trying to start it and the longer I waited it would try to start then die. Left it over nite and the next day it started and ran perfectly... forabout an hour then a constant miss at 55 MPH. At the first traffic light it died at idle and wouldn't start. After a couple of hours it would start perfect and run good for about half an hour. Each episode got worse.

Bottom line was it was the injectors. Story I got was that ethenol fuel destroys the windings. The engine heat causes them to fail but will recover after they cool down.

Good luck getting home.

Churchkey

If fuel pressure is ok:

Pick up a cheap digital ohm meter. (Corvette = never leave home without one) When the motor quits unplug & test each injector for 14-16 ohms. If you find a low reading injector leave it unplugged, the motor should now start/run. You can limp it around on 6-7 cylinders without damage to the disconnected cylinders. Unlike bad spark, no fuel in a dead cylinder = no fuel wash on the cylinder walls.

GL

C4fan

I have a stock set of injectors in Oklahoma City if it would help.

Railroadman

OK guys, here's the update.

After a few hours sleep we left Amarillo about 7:20, temp was about 73 degrees. Kept the AC off, and made it all the way back to Clinton Oklahoma with no shut-down. A couple times I almost thought I felt a little shudder but maybe I was just paranoid. By the time we got here it was mid 80's and warming up fast. So that's 2 1/2 hours and 175 miles no problem when starting a cold car and cooler air temps.

Got thinking - will a fuel pressure gauge help me if the car is NOT acting up? Obviously we had enough to do what we did this AM and yet yesterday when it died it was not getting fuel. The way it ran today I'm thinking the injectors are OK, thanks for the offer.

Also, since there was no backfire when it died it would seem the ignition is OK, it's simply lack of fuel. So should we rule out the ICM? Gotta admit I don't have a full complete understanding what all these modules do.

At this point I'm still leaning toward either ECM or fuel pump/pulsator, but I'm willing to listen if someone still thinks otherwise.

Our plan was to head south from here Wednesday AM, and that was going to take us through a lot of small towns and back roads. I don't want to have it die in West Jockstrap somewhere, but also don't want to head home and have it run perfectly after I replace whatever we come up with. Unfortunately the only way to determine if it's fixed is to drive it and see if it fails.

I'm going to sleep a bit, woke up at 5AM after going to bed at 2AM. That's fine when I was 20 or 30, but..... The wife is content, so she's going to read a book or hit the pool and I'll rest up and check back in if the hotel's computer lets me.

Again thanks for the help and support. Other than the car problems we're having a ball - Texas hospitality is not a myth, they have some great and friendly people!

Midnight 85

Keep the ice handy, if it acts up and ice on the ecm fixes it you've found it. I sure feel for you, this sort of thing is bad enough in everyday driving but on vacation it oughta be against the law.

sailorsteve

Were you able to look for codes?

I know it's on vacation, and far from home, but is it feasible to connect a fuel pressure gauge and tape it to the windshield, then try to make the car misbehave? Would be nice if you could eliminate the pump as an issue.

Frizlefrak

If it's running fine now, you may have gotten ahold of some bad fuel too....

Hate to say this, but fuel pressure really needs to be tested during an event. If you plan on heading out, you might buy a fuel pump, some FI hose, and a socket set.....you can change a fuel pump by the side of the road in 30 minutes if need be.

I'm not one to throw parts at a problem, but given your symptoms, a spare might be a good idea. Hell, pick up an ICM while you're at it....another easy fix. Us Fiero owners carry a spare module everwhere we go.

96 Vette CE

Don, the fuel pressure gauge will help you to determine if the fuel pump is failing when the pump itself gets hot. Unfortunately, the only way you will be able to tell this is when it starts acting up again. At least then you could rule that out as a possibility.

Have you checked to see if it is throwing any codes? It could point you in the right direction of trouble shooting at the very least.

Keep us posted.

96 Vette CE

Ok Friz, you're faster at typing than i am.