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It's been a while since I've been on here. All has been going well until now. I am starting to have fuel issues again. It went away but now it's back with a vengeance!!!!
Once I get "close" to a 1/4 tank, the car sputters, hesitates and backfires real bad! this morning, I had 3/4 of a tank.
The fuel pump is not even a year old, same with the sending unit. Fuel filter in only about 8 months old. I've regularly added injector cleaner and just added some seafoam. I don't know what else to do.
Have you tried to drive with a Fuel Pump pressure Gauge attached to the windshield so you can see "what is" happening "while it is happening"? It would be worth trying it to see what is actually happening when the Engine acts up. If you have a real time scanner that would be even better.
Like 3d-Aircrew wisely suggested the Fuel Pressure Regulator is a potential culprit. Remove the vacuum line that attaches to the FPR and smell inside of the hose, if it smells like gasoline then you are sure that it is defective. If you do replace it do so with the diaphragm replacement as opposed to replacing the entire unit which is more expensive. When I did mine it was easy to replace once you got it exposed.
Another potential would be the little sock that attaches to the end of the fuel pump. If they get blocked off or plugged up they limit the gasoline flow. Sometimes they even fall off the the fuel pump and then the pickup is fairly high up. Holley makes a new style pickup mat that attaches to the same point on the fuel pump. The new material is incredible and a bit expensive as well. It is called Holley "Hydra-Mat" and it is really great stuff especially if you are racing the Corvette. If you have not heard of it take a look, this stuff is amazing.
One last thing, My 1988 C4 sat for almost 2 years and when I started it the car would not start and stay running for more than a few seconds. It turned out that my Fuel Supply Line coming from the tank to the fuel filter had actually corroded closed "internally". It would allow some fuel to get through and the pressure was good but there was not enough volume of fuel for the car to run properly. I ran a hose around it and the car ran fine. Ethanol absorbs water and holds it at the lowest point in the fuel line. The only way to identify this is to measure the fuel volume flow, I measured it with the plugged line and with the open hose, a huge difference.. I hope that you don't have to deal with this but it does happen...
Having a 1988 C4 I offer my help, the 1988 Corvette has some unusual parts and systems. The 1988 has the new improved parking brake! The 1988 C4 also has a "one-year" Brake system. One of my brake lines rusted through as well. It was one line but the entire master cylinder drained out through the hole and that is not good. The systems is supposed to have totally separate reservoirs for the Front and Rear brakes on the Corvette which would allow you to stop in case of brake line failure. The 1988 does not.... Make sure that you have a good functional Emergency brake.
The Emergency brake IS powerful enough to stop the Corvette in case of a brake line rupture IF IT WORKS. Be sure it always works on the 1988 Models especially an automatic transmission equipped C4. The 1988 C4 does not use the drum brake inside the rotor like previous and later Corvettes, it actually pulls the brake to squeeze the rotor and stop the car. I had a master cylinder fail while driving a BB 1968 C3 at 70+ mph in traffic. Had it not been a manual I would have been in real trouble. Having experienced it once it will not happen again on any of my cars.
Have you tried to drive with a Fuel Pump pressure Gauge attached to the windshield so you can see "what is" happening "while it is happening"? It would be worth trying it to see what is actually happening when the Engine acts up. If you have a real time scanner that would be even better.
Like 3d-Aircrew wisely suggested the Fuel Pressure Regulator is a potential culprit. Remove the vacuum line that attaches to the FPR and smell inside of the hose, if it smells like gasoline then you are sure that it is defective. If you do replace it do so with the diaphragm replacement as opposed to replacing the entire unit which is more expensive. When I did mine it was easy to replace once you got it exposed.
Another potential would be the little sock that attaches to the end of the fuel pump. If they get blocked off or plugged up they limit the gasoline flow. Sometimes they even fall off the the fuel pump and then the pickup is fairly high up. Holley makes a new style pickup mat that attaches to the same point on the fuel pump. The new material is incredible and a bit expensive as well. It is called Holley "Hydra-Mat" and it is really great stuff especially if you are racing the Corvette. If you have not heard of it take a look, this stuff is amazing.
One last thing, My 1988 C4 sat for almost 2 years and when I started it the car would not start and stay running for more than a few seconds. It turned out that my Fuel Supply Line coming from the tank to the fuel filter had actually corroded closed "internally". It would allow some fuel to get through and the pressure was good but there was not enough volume of fuel for the car to run properly. I ran a hose around it and the car ran fine. Ethanol absorbs water and holds it at the lowest point in the fuel line. The only way to identify this is to measure the fuel volume flow, I measured it with the plugged line and with the open hose, a huge difference.. I hope that you don't have to deal with this but it does happen...
Having a 1988 C4 I offer my help, the 1988 Corvette has some unusual parts and systems. The 1988 has the new improved parking brake! The 1988 C4 also has a "one-year" Brake system. One of my brake lines rusted through as well. It was one line but the entire master cylinder drained out through the hole and that is not good. The systems is supposed to have totally separate reservoirs for the Front and Rear brakes on the Corvette which would allow you to stop in case of brake line failure. The 1988 does not.... Make sure that you have a good functional Emergency brake.
The Emergency brake IS powerful enough to stop the Corvette in case of a brake line rupture IF IT WORKS. Be sure it always works on the 1988 Models especially an automatic transmission equipped C4. The 1988 C4 does not use the drum brake inside the rotor like previous and later Corvettes, it actually pulls the brake to squeeze the rotor and stop the car. I had a master cylinder fail while driving a BB 1968 C3 at 70+ mph in traffic. Had it not been a manual I would have been in real trouble. Having experienced it once it will not happen again on any of my cars.
Best regards,
Chris
Hi Chris,
Well it's been a little bit, but we took your advice and replaced the FPR. It did need it since the vac hose and the throttle body and plenum was coated with fuel inside. Thank you for that. But I will have to say, that was not the issue. After the new FPR and cleaning the plenum and TB. It still did exactly the same thing... So, I pulled the fuel pump and sending unit just to inspect it. And there was a lot of very fine rust in the trough where the FP sock was and that was almost completely clogged. So, I cleaned that out and checked the fuel filter, which was just a few months old and it was really gunked up. So I replaced that and Now all is well in the world. But I just wanted to thank you for your suggestion. It really needed that.
Fuel Issues
