Fresh 88 Vette convertible owner and trying to get her to run so I can turn her into my daily driver. Starts a little tough when cold, fine warm. Runs great for about 5-10 mins until engine is hot then engine bogs down, falls flat, at 2000-2500 RPMs after in gear. If I turn it off for a minute and start it back up, it will rev fine, but once I get it back under load in gear, it will start to stumble again.

It has been in storage for a couple years. Tank was emptied and cleaned, replaced sending unit, fuel pump, fuel filter, fuel pump relay. I have not replaced the fuel pressure regulator yet. Filled with full tank of premium and some Lucas injector cleaner. It was throwing code 54, "low fuel pump voltage or EGR #2", so replaced the fuel pump relay, cleared the code and it still behaves the same way. The code though has not returned.

I'm thinking injectors as the most likely candidate as they I'm sure are the originals. Any ideas from the Sages on this fine site is greatly appreciated.

Please help...I can't wait to get out on the road and enjoy this fine machine.

Tony

 

Sounds like my '89 coupe. Change the injectors first. If they are the originals you need new ones to accept the new fuel mixture. If that doesn't work, look at the cats. That was my problem at 87,000 miles. I got new cats and all is good again. Got my power back, better gas mileage and it runs cooler. Contact FIC. He's a member here and can help with the injectors.

 

After two years of sitting the filters in the injectors could dry rot, fall apart and restrict the flow...

 

I had a problem similar to yours on my '87, a parts house loaned me a fuel pressure tester, I hooked it up and taped it to the windshield while I drove around. Pressure was good but eventually fell to 32 lbs or lower. When I finally changed the pump and twice changed the fuel filter, the car ran like it was on nitrous. Good luck.

 

We changed the fuel pump and filter both out once already so not sure what to try next outside of taking measurements on the injectors cold then hot. I was hoping it was just the fuel pump and filter but it runs the same way before and after.

 

Have you checked the fuel pressure?

 

FICinjectors.com Jon is the guy

 

Tried that URL and it doesn't work. Typo?

 

I haven't but my father-in-law said he did and it read within spec at idle when cold and degraded when it warmed up. His gauge is in Indy so I will have to go and buy one to check it here. Suggestion of the technique and results I should expect/look for?

 

Try ficinjectors. Jon Banner is his name and he is a member here. Click where you find "search members" and type in ficinjectors. All lower case. It will change to upper case on its own.
Better yet, I bet he will find you first. That's how good he is.

 

Are you saying it will not rev past 2500 in gear? And runs out of power?

 

Yes, in gear I can floor it and once it gets to 2-2.5k RPMs, it just falls on its face and loses all power.

 

Had a similar problem after using Lucas oil it damaged the wet coil and they shorted out .contact Jon at FIC

 

Took her out for a quick spin tonight and she drove fine until about 10 mins in, 165 degs started to bog down when I gave it the gas. If I floored it, she'd almost die but start popping underneath the car. Is this a clogged cat? Just so weird how it seems fine when cold then gets a little warm and blah!

 

If it's the cats eventually the bogging will begin earlier and at a lower RPM until it goes so slowly you'll be forced, for safety sake, to have it towed to the muffler shop to have the cats changed. Why wait? I did and it's a good thing I have free towing through AAA. Now it behaves like a Corvette should.
Oh, and you really should change the injectors on general principle. That job you can do yourself with a little patience. Buy them here. We have a vendor (ficinjectors). Price them anywhere else and they will be big bucks.They should be changed as a set. We can walk you through it.

 

"Runs great for about 5-10 mins until engine is hot then engine bogs down, falls flat, at 2000-2500 RPM"

To me this sounds electrical.

Maybe the module in the distributor.

Runs fine until it gets hot then breaks down under heat.

$55.00 you can get a better performing unit.
The Accel unit is 50 state legal.

Ralph

 

Can anyone comment to how it may behave if the Fuel Pressure Regulator is defective? I've replaced everything in the fuel system except for the injectors and the FPR. Just trying to rule out the lower cost items before jumping into the big ticket ones. Is there an easy method for determining if the FPR is good or bad?

 

 

Everyone thinks changing injectors is a cure all, Go ahead, give it a shot. Worst case you'll have new injectors

ps. FIC is a good company...

 

Duly noted...

Question re: expense of doing these two items. I see I can get the injectors from Jon for less than $400 and plan to do those myself.

The cats on the other hand, though not terribly expensive for the parts, will prove to be much more expensive as it is most likely an item I'd have to have done by someone else.

What is an expected, fair price for having the cats replaced? And, how do I know if I truly do need them replaced? Just the main? All three (precats)?

Thanks in advance!