1988 corvette
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Joined: Mar 2001
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Likes: 24,825
From: In a parallel universe. Currently own 2014 Stingray Coupe.
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Moving this to the C4 Tech section.
Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
Welcome to the Forum!
In your quest to fix your car who did the work? Did you do both heads or just the offending one?
After major work like that it is likely that something simply did not get reconnected the right way.
I would check around the area where the work was done and look for any vacuum hoses that might have not been re-connected. It could be a loose wiring connector or loose spark plug wire or one of the many sensors that help our cars run right. I would look carefully at or around anything that was moved or disconnected to allow the work to be done.
On our cars (I have an 1988 Coupe) the vacuum hoses are getting very old and dried out. Long ago my car started running roughly and the idle speed fluctuated and it turned out just to be a vacuum hose broke off near the cruise Control, I cut off 3/4 " hose and reconnected it. I have also found and fixed a vacuum leak at the EGR vacuum solenoid near the Thermostat Housing same problem, loose fitting hose. Spend time looking around to be sure that everything is plugged in correctly. I would even verify that your spark plug wires are going to the proper cylinder. Did they make any modifications to the car when fixing the head gasket?
Look for any vacuum leaks, if your hearing is normal than you might hear them. Depending on which head was done is it possible that you got any coolant on O2 sensor? It is very easy to "poison" an O2 sensor with things like coolant or even the wrong anti-seize can do it.
The temperature sensors are very important to our model, we have two of them, one for the ECM and one for the digital dash. If the ECM sensor goes south it might be thinking that the engine is warm when it is in fact cold, this can make it run poorly. Are the problems in both the "Open Loop"mode or does it happen in the "Closed Loop" mode as well?
The more details you can provide us would help the other owners on this forum help you out. Is your car displaying any codes? Anything pertinent to the way the engine is/was running? What caused the head gasket failure? How many miles are on the car/engine? Has the engine been modified or is it all stock? The more information you post will help us help you.
Dozens of issues are resolved regularly by the people on this forum as the collective experience here is unbelievable! You came to the right place so please post anything else that might help us.
My hope is that we can help you get that Corvette of yours back on the road again, quickly, inexpensively and reliably! Good Luck!
After major work like that it is likely that something simply did not get reconnected the right way.
I would check around the area where the work was done and look for any vacuum hoses that might have not been re-connected. It could be a loose wiring connector or loose spark plug wire or one of the many sensors that help our cars run right. I would look carefully at or around anything that was moved or disconnected to allow the work to be done.
On our cars (I have an 1988 Coupe) the vacuum hoses are getting very old and dried out. Long ago my car started running roughly and the idle speed fluctuated and it turned out just to be a vacuum hose broke off near the cruise Control, I cut off 3/4 " hose and reconnected it. I have also found and fixed a vacuum leak at the EGR vacuum solenoid near the Thermostat Housing same problem, loose fitting hose. Spend time looking around to be sure that everything is plugged in correctly. I would even verify that your spark plug wires are going to the proper cylinder. Did they make any modifications to the car when fixing the head gasket?
Look for any vacuum leaks, if your hearing is normal than you might hear them. Depending on which head was done is it possible that you got any coolant on O2 sensor? It is very easy to "poison" an O2 sensor with things like coolant or even the wrong anti-seize can do it.
The temperature sensors are very important to our model, we have two of them, one for the ECM and one for the digital dash. If the ECM sensor goes south it might be thinking that the engine is warm when it is in fact cold, this can make it run poorly. Are the problems in both the "Open Loop"mode or does it happen in the "Closed Loop" mode as well?
The more details you can provide us would help the other owners on this forum help you out. Is your car displaying any codes? Anything pertinent to the way the engine is/was running? What caused the head gasket failure? How many miles are on the car/engine? Has the engine been modified or is it all stock? The more information you post will help us help you.
Dozens of issues are resolved regularly by the people on this forum as the collective experience here is unbelievable! You came to the right place so please post anything else that might help us.
My hope is that we can help you get that Corvette of yours back on the road again, quickly, inexpensively and reliably! Good Luck!
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
Welcome to the forum!
In order to help you, it would be very helpful if you could post some very specific details of your issue. Does it happen at all RPMs, or a specific range? Under load, or all the time? How does it idle? Any strange sounds? A video could also be really helpful.
Looking forward to your issue being resolved and you getting to enjoy your car!
In order to help you, it would be very helpful if you could post some very specific details of your issue. Does it happen at all RPMs, or a specific range? Under load, or all the time? How does it idle? Any strange sounds? A video could also be really helpful.
Looking forward to your issue being resolved and you getting to enjoy your car!
Le Mans Master
Joined: Oct 1999
Posts: 6,366
Likes: 34
I am no mechanic, but it sounds like it is broken 
Can you tell us more. We don't have to get too technical or anything, like how many knock counts you are getting on the lunar wayne shaft.
Describe how it run really rough is all we ask.
Can you tell us more. We don't have to get too technical or anything, like how many knock counts you are getting on the lunar wayne shaft.
Describe how it run really rough is all we ask.
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