88 Bogging after warm
#1
Racer
Thread Starter
88 Bogging after warm
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
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
#2
Instructor
are you me?
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.
#4
Advanced
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.
#5
Racer
Thread Starter
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.
#9
Racer
Thread Starter
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?
#10
Instructor
ficinjectors
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.
Better yet, I bet he will find you first. That's how good he is.
#12
Racer
Thread Starter
#14
Racer
Thread Starter
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!
#15
Instructor
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.
#16
Burning Brakes
Member Since: Feb 2011
Location: Woodland California
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"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
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
#17
Racer
Thread Starter
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?
#18
Team Owner
Member Since: Oct 2004
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St. Jude Donor '05
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.
#20
Racer
Thread Starter
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!
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!