edram454

I recently bought a 33k mile 1995 corvette convertible. the issue is when I am cruising around 40 mph, the car slowly wants to stop applying power, like a fuel issue or something, and when I push the gas it will sputter and not accelerate until it gets slower and slower. I pull off the road and turn it off. I turn it back on and problem is gone. the car never dies just slowly slows down not letting me accelerate. could this be bad gas, bad fuel filter, fuel pump etc... the car has new injectors by previous owner, new alternator and a new starter I put today.. when its under power it runs great. this just happens all of a sudden. It may not happen at all one day and get me the next. no smell of gas. ideas??

thanks.

jv9999

Try driving it with the gas cap loose. The evap solenoid might be sticking.

1984Z51auto

It would be interesting to see the fuel pressure reading when it is running poorly as this sounds like a fuel delivery issue: pump, filter in tank, filter in line kind of thing. I'm not sure you can do it on a '95 however, on an '84 you "can" put the in line fuel filter in backwards. If you do the interior cap can come off the fuel filter element and block the outlet. It has exactly the indications you give. You may be able to guess how I know that!

edram454

I am thinking its the fuel pressure regulator. it is definitely starving for fuel when it starts to bog and decrease in speed. I also read it might be the IAC whatever that is? Thanks for your comments. ed.

1984Z51auto

IAC = Idle Air Control. Probably not the culprit as it is just an air bled to control idle speed. I'll bet you find the problem with a fuel pressure test.

hcbph

Be aware that with the newer fuel systems you can throw codes if the gas cap is not on tight. it would be worth a test but know if you suddenly get a emissions related code that might be the cause.

Just fYI.

redcorvettedave

I love these threads, this give me (a pure novice) a chance to give advice like I'm a real corvette expert. But opti symptoms i know quite well I have replaced 6 on my 94 over the course of 20 years.

Its your Opti:

oilyfishhead

I doubt it. The 95 opti is a much better unit than the 94 and with only 33K on it it should be fine.

Sounds like fuel to me.

edram454

thanks for your opinions. I will try to gas cap, fuel regulator and if all else fails, the opti spark. I have seen opti sparks on ebay for 150.00? are these good?

Masterho

I had a similar problem with my '94. The fuel pressure regulator(FPR) was good, the fuel pressure was within spec and held pressure for hours after shutdown, and the fuel filter was changed 20k miles ago. The culprit was a faulty fuel pump relay, which is located behind the passenger-side dash. It worked intermittently, causing stalling when the engine came up to operating temperature. $12 later, problem solved.

Mr. Peabody

I've got a 95 just like you. Sounds more like a fuel delivery problem to me.

A fuel pressure gauge rigged up so that you or a friend can see it when the problem manifests itself will be a good (inexpensive) test.

Your C4 is not a car that you want to throw parts at trying to solve a problem.

You have more testing before you determine that it needs a replacement opti. I've driven my 95 more than 50,000 miles in the rain and no opti problems. (it rains here almost every single day 7- 8 months of the year)

3D-Aircrew

Check for any fuel in the vacuum line to the fuel pressure regulator.

This is what a bad FPR diaphragm looks like: