Rough idle
Thread Starter
Cruising
Joined: Feb 2023
Posts: 13
Likes: 1
Rough idle
Hello I have a 88 corvette that I’ve been dealing with after finding out my injectors were bad and leaking gas into the engine I got some Bosch 3s from SouthBay I’ve changed spark plugs fuel pump, fuel filter distributor, alternator, coolant temp sensor, spark plug wires, changed the oil and now the injectors thinking it would finally be done I start the car it sits for a few minutes at idle then I hear a pop from the exhaust the rpm’s drop a little then I hear a loud clicking sound and the exhaust constantly pops the clicking sounds like it’s coming from the fuel regulator it doesn’t change when I pull the throttle and I can’t seem to think of what the issue is unless a spark plug got burned out from gas or something this car only has 73000 miles on it so I can’t imagine it’s anything internal has anyone else had this kind of issue?
Instructor
Joined: May 2023
Posts: 120
Likes: 10
Does it lqck power when pressing on gas? If yes change both fuel filter, one in the tank, one outside the tank under passenger side close to windsheild liquid box. Also im not shure cuz i have a 84 but maybe check either tps or your tdc and check your true timming.
Drifting
Joined: Jul 2022
Posts: 1,805
Likes: 365
From: Central Florida
Not long ago I contacted South Bay and they said they had never heard of such a thing (injectors yes regulator no). I have been on my search for this answer now for several months and after over using my wrist on the car had to take several months off. My car runs like crap after it warms up so I may have a second problem or the tapping may be lifters or the fuel pressure regulator or the delete of the fuel pump pulsator. I am at a stand still repairing while I learn how to view data and get up and running with software and cables, another fiasco I self created. My mechanics stethoscope first pointed to the valve covers then the fuel rail and then fuel pressure regulator but that was after weeks and weeks of re lashing the valves and asking the forum for help. I can't truly tell if it is the FPR or a harmonic from the engine somewhere. I too had original injectors and went through the top end cleaning and replacing stuff that was 35 years old including intake gaskets, injectors, fuel pressure regulator, vavle stem seals, EGR, sensors, orings, etc etc. Good luck, I too have the problem but no definitive answer for you. I have several post with audio files at the bottom. Can you feel the tapping in your FPR ??
These are my post and others with the problem.
https://www.thirdgen.org/forums/tpi/...or-making.html
https://www.corvetteforum.com/forums...ng-valves.html
https://www.corvetteforum.com/forums...-from-fpr.html
https://www.thirdgen.org/forums/tpi/...injectors.html
These are my post and others with the problem.
https://www.thirdgen.org/forums/tpi/...or-making.html
https://www.corvetteforum.com/forums...ng-valves.html
https://www.corvetteforum.com/forums...-from-fpr.html
https://www.thirdgen.org/forums/tpi/...injectors.html
Last edited by Vets-Vet; May 29, 2023 at 02:24 PM.
Racer
Joined: Oct 2012
Posts: 280
Likes: 82
From: Indiana
Did you check fuel pressure while running? EGR valve that is stuck open, vacuum leaks from all the rubber vacuum lines, a vacuum leak at the throttle body shaft, and lastly double check the routing of your plug wires to be sure you don't have two mixed up.
Thread Starter
Cruising
Joined: Feb 2023
Posts: 13
Likes: 1
I pushed my timing from 6 to 8 and the popping stopped and it stopped when I unhooked the timing wire so I assume the popping is from a sensor but I used a screwdriver to locate the noise and can’t hear it anywhere but the regulator
