StoobyMcDooby
09-27-2011, 11:34 AM
Hello,
I have just finished my 5 speed swap on my 1991 HB. The car has 163k on it, and drove/ran perfect before converting to manual. I did all of the work myself for the swap. Anyhow, the car drives perfect since converting. However, the idle tends to stay high (around 1800 RPM) when I come to a stop, and then after 2 to 7 seconds, it calms itself down to the normal 750 RPM. Once it settles down back to normal, it stays there until I apply throttle once more.
It does NOT surge up and down. When the car is started, whether the car is cold or warmed up, it idles perfectly normal.
It is important to note, that while rolling in Neutral, no matter what speed, the idle remains constant at 1700 +- RPM, and will not settle down unless the car is completely stopped - thus indicating that the vehicle speed is affecting the idle speed.
I first used the automatic ECU that was original to the car, but have since switched to a manual ECU hoping this would resolve the issue and it has not.
Remember, the idle was PERFECT one week ago, right before I performed the swap. I did every moment of the swap myself, and I did not touch anything on the motor. The closest I got to taking anything off of the motor was removing the starter, but that's it. I have not found any vacuum leaks, and nothing else has been messed with.
I have done multiple vacuum tests, and there are NO leaks.
I unplugged the automatic trans computer (found above the ECU), and it didn't help. When the car is idling high, I tried to close the throttle plate to make sure that it wasn't sticking open - and it was closed fully, even while idling high.
Any insight would be greatly appreciated! Sorry for the lengthy read.
I have just finished my 5 speed swap on my 1991 HB. The car has 163k on it, and drove/ran perfect before converting to manual. I did all of the work myself for the swap. Anyhow, the car drives perfect since converting. However, the idle tends to stay high (around 1800 RPM) when I come to a stop, and then after 2 to 7 seconds, it calms itself down to the normal 750 RPM. Once it settles down back to normal, it stays there until I apply throttle once more.
It does NOT surge up and down. When the car is started, whether the car is cold or warmed up, it idles perfectly normal.
It is important to note, that while rolling in Neutral, no matter what speed, the idle remains constant at 1700 +- RPM, and will not settle down unless the car is completely stopped - thus indicating that the vehicle speed is affecting the idle speed.
I first used the automatic ECU that was original to the car, but have since switched to a manual ECU hoping this would resolve the issue and it has not.
Remember, the idle was PERFECT one week ago, right before I performed the swap. I did every moment of the swap myself, and I did not touch anything on the motor. The closest I got to taking anything off of the motor was removing the starter, but that's it. I have not found any vacuum leaks, and nothing else has been messed with.
I have done multiple vacuum tests, and there are NO leaks.
I unplugged the automatic trans computer (found above the ECU), and it didn't help. When the car is idling high, I tried to close the throttle plate to make sure that it wasn't sticking open - and it was closed fully, even while idling high.
Any insight would be greatly appreciated! Sorry for the lengthy read.