L98 Trans Am misfire issues..
10-27-2015, 11:55 AM
#1
Junior Member
Thread Starter
L98 Trans Am misfire issues..
Hello guys,
I am writing you from Romania. I have an 89 T/A L98 700R-4 w/ Magnaflow exhaust.
Well, i had big issues with the injectors, 3 of them were not working fine and the engine was running really bad, like just a few pistons and giving a lot of smoke, so i changed them.
I bought exactly these: http://www.southbayfuelinjectors.com...rvette-c4-l98/
Anyhow, i installed them and i puted all together on the car, the engine was idling, not giving smoke anymore but there was still some small interrupting, anyhow was with the final exhaust removed.
Today i puted new spark plugs and installed back the exhaust. I started the car .. and, at some point it began to give misfires, like regulary .. every few seconds.
Do you guys have any idea what can be the cause ? I mean beside the spark plug wires and distributor ...because they were also changed not to long ago and the car was running fine.
I changed all the gaskets from the intake, on the AFR is on green showing ~14.6.
The guy who is taking care about doing this is telling me that basically there's going more petrol than normal.
Also there's low vacuum. I mean when i remove the hose from the plenum there's like no any lost pressure sound, and i also have issues with the brakes, probably because of this. Can the vacuum be an issue ?
Before the car was running fine, just the problem with the brakes which were not holding even with new discs, calipers, pads and pump. At some point, sudenly when i started it, it began to run in less than 8 pistons, giving smoke etc.
Thanks !!
I am writing you from Romania. I have an 89 T/A L98 700R-4 w/ Magnaflow exhaust.
Well, i had big issues with the injectors, 3 of them were not working fine and the engine was running really bad, like just a few pistons and giving a lot of smoke, so i changed them.
I bought exactly these: http://www.southbayfuelinjectors.com...rvette-c4-l98/
Anyhow, i installed them and i puted all together on the car, the engine was idling, not giving smoke anymore but there was still some small interrupting, anyhow was with the final exhaust removed.
Today i puted new spark plugs and installed back the exhaust. I started the car .. and, at some point it began to give misfires, like regulary .. every few seconds.
Do you guys have any idea what can be the cause ? I mean beside the spark plug wires and distributor ...because they were also changed not to long ago and the car was running fine.
I changed all the gaskets from the intake, on the AFR is on green showing ~14.6.
The guy who is taking care about doing this is telling me that basically there's going more petrol than normal.
Also there's low vacuum. I mean when i remove the hose from the plenum there's like no any lost pressure sound, and i also have issues with the brakes, probably because of this. Can the vacuum be an issue ?
Before the car was running fine, just the problem with the brakes which were not holding even with new discs, calipers, pads and pump. At some point, sudenly when i started it, it began to run in less than 8 pistons, giving smoke etc.
Thanks !!
11-02-2015, 12:22 PM
#2
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Join Date: Nov 2009
Location: Mersea island UK
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Car: 1989 Trans Am GTA
Engine: Procharged 350tpi
Transmission: uprated 700R4
Re: L98 Trans Am misfire issues..
are you sure you did not mix up plug leads
other possibility is one of the intake/plenum/runner gaskets not in position or split, or maybe a bolt not tight
did you check O rings on injectors all fitted correctly
other possibility is one of the intake/plenum/runner gaskets not in position or split, or maybe a bolt not tight
did you check O rings on injectors all fitted correctly
11-03-2015, 03:32 PM
#3
Junior Member
Thread Starter
Re: L98 Trans Am misfire issues..
i will check with my mechanic to check it.
he fixed some missing vacuum and now it's working almost fine idling, i mean there are not any missfires ...but, as soon as i put it in D and go for a walk it begins to give missfires, the more i go faster the more missfires i hear.
it's quite difficult for me with this car in Europe ...
he fixed some missing vacuum and now it's working almost fine idling, i mean there are not any missfires ...but, as soon as i put it in D and go for a walk it begins to give missfires, the more i go faster the more missfires i hear.
it's quite difficult for me with this car in Europe ...
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