HELP - Grand Am revving/idling at 3000 rpm

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Hi, I hope someone can help. I changed the motor in my 88 grand am quad 4 dual overhead cam and now when you start it it runs at 3000 rpm's and I can't lower it. The motor I replaced it with is a 91 dual overhead cam 2.3. I changed the air flow sensor, throttle body positioning sensor but I used the thottle body from the 88 quad 4. The motor runs fine except for the high rev. There is no vacuum leaks. I am wondering if the fuel rail system has more fuel pressure from the 88 compared to the 91. It seems to be getting more fuel than required when you put your hand over the throttle body to try and starve it for air it still doesn't idle down. I don't know what to think because I was told by GM that this 91 is the same motor except I had to use all the sensors and throttle body off my 88. If anybody can help diagnose this problem it would be greatly appreciated. NOTE: I did not change the sensor for timing and it's not running rich or lean.

posted by  dlvinet

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