Help! Looking for tips, suggestions or advice
Thread Starter
Heel & Toe
Joined: Mar 2020
Posts: 15
Likes: 1
From: Fox Valley, WI
Help! Looking for tips, suggestions or advice
I bought my 1990 Base coupe vette. I have replaced the tires, the spark plugs, plug wires, Distributor cap and Rotor, and pcv valve. I have run C-foam through it, fuel injector cleaner through it. It idles, very rough, and after about 30 seconds of idling, it will idle out completely. A friend suggested the timing might be off, he also recommended replacing the EGR valve, the Idle Air Control Valve. I am at a loss, as to the direction to go. I do not have a check engine light on. Anyone else have this problem and might know what direction to go in?
Thread Starter
Heel & Toe
Joined: Mar 2020
Posts: 15
Likes: 1
From: Fox Valley, WI
Not sure if the injectors are original or not, they are on the list to replace however. Not sure what the fuel pressure is either.
Safety Car
Joined: Jan 2004
Posts: 4,549
Likes: 343
From: Glastonbury CT
Run some fuel injector in to your gas tank and let idle to see if it will smooth out.Also the 90 service manual you should have and follow before you toss a lot of parts at it.How old is the gas? How about the fuel filter has it ever been changed? How are the vacumn lines ? Do a visual inspection of motor. Start simple, any codes? Do you have history of vehicle? Last this forum has a lot of information just ask.
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Thread Starter
Heel & Toe
Joined: Mar 2020
Posts: 15
Likes: 1
From: Fox Valley, WI
Ok, so I checked the Fuel Injectors, from the firewall down passenger side around the front and back to drivers side firewall
Firewall
15.80 | 16.20
16.00 | 16.20
16.10 | 16.10
16.10 | 14.50
From what I have seen and read, they should be above 16.00, is this correct? DO I have 2 that need to be replaced?
Firewall
15.80 | 16.20
16.00 | 16.20
16.10 | 16.10
16.10 | 14.50
From what I have seen and read, they should be above 16.00, is this correct? DO I have 2 that need to be replaced?
Thread Starter
Heel & Toe
Joined: Mar 2020
Posts: 15
Likes: 1
From: Fox Valley, WI
Run some fuel injector in to your gas tank and let idle to see if it will smooth out.Also the 90 service manual you should have and follow before you toss a lot of parts at it.How old is the gas? How about the fuel filter has it ever been changed? How are the vacumn lines ? Do a visual inspection of motor. Start simple, any codes? Do you have history of vehicle? Last this forum has a lot of information just ask.
Pro
Joined: Feb 2009
Posts: 541
Likes: 60
From: Auburndale Florida 1990 Vert, 6 speed
I think your fuel injector resistance may be ok. I seem to remember a much bigger discrepancy reading between injectors when my originals went bad. Does your car run/drive fine otherwise? Is your problem only at idle?
Thread Starter
Heel & Toe
Joined: Mar 2020
Posts: 15
Likes: 1
From: Fox Valley, WI
Even while running it is rough, but even more so at an idle. I have an EGR valve on order should be here tomorrow. Once I get it all back together I will run the Fuel Pressure test on it and see what it comes up with. Will let you guys know more later this week.