idle problem

[fc nut]

a friend of mine bought an 87 gxl with 231k miles. a previous owner replaced the engine with 105k on it. they also replaced the fuel lines and some of the vaccum lines. he replaced the bac and airflow meter. someone tried to fix the issue, they tried to adjust the idle,but couldn't get it right. they sold the car to a guy i know. i looked at it and all the vac lines are in their correct spots, i reset the tps,i even retarded and advanced the timing a bit and still nothing. i got the idle down to 1200 rpm,but if you rev it it jumps to 1500 and stays there. he replaced the radiator,water puump and thermostat as well. is there a sensor that controls the cold start system?

[RETed]

It sounds like something is stuck in the throttle body.
Typically, the coolant passages in the coolant body (or in the hoses going in and out of it) get clogged, which prevents proper flow of (hot) coolant to the thermowax that allows the idle to "kick down" once the engine warms up.

If a previous owner f*cked with the throttle body, that'll prevent the thermowax from doing it's job too.


-Ted

[fc nut]

thanks for the input. i'll check it the next time i go to his house.