the motor is in my daily driver ( an 87 s-15 gmc jimmy) it is a 87 tpi 350 that came from an iroc, when i start the engine it idles at 1000 rpm after a few min. it slows to 450-750(hunting) then goes back up to 1000, it also seems to miss at times. i have installed new plugs, wires, cap and rotor any other suggestions

 

Check for vacuum leaks, and clean the IAC motor and throttle body.

 

Hook up a scan tool and see what you get for Idle Air Counts. Should be around 20 - 30. If you get 0, you turn the screw for adjustment anticlockwise till you get the reading you want.

 

to do that i need to find the 3rd 8th and 10th digits of the vin number of an 87 iroc 350 tpi. Can anyone give me the numbers?

 

Try this 1 8 J. The only problem is that according to Chilton, 87 did not come with a 350 TPI. The number I gave you was for an 88. J is 88 and H is 87. 8 is 8th digit which tells it that this is for a L98 and the first digit is 1 which stands for Chevy

 

thanks i will try that on saturday and let you know how it works.