wont idle until warmed up

[talk2elk]

I have an 88 gl wagon 4x4 non turbo 1.8 spfi that wont idle at a cold startup. Runs fine after it warms up. Had a mechanic friend helping try to fix it..... trying to fix myself again. Where is the best place to start? Replaced water pump, timing belts, gaskets, computer, relays, wiring harness, and some more stuff. Sick of throwing money at it! I know I must be missing a small detail somewhere. Any suggestions would be greatly appreciated. I love this car and need to keep it on the road (312,000 miles!) The block is the only thing original under the hood (bought it from a guy that worked at Subaru dealer that rebuilt it) and I have a spare everything.

[shadow]

Thread moved to the "Old Gen" section from "Site Help", you should get better exposure for your problem in here!

[Caboobaroo]

Have you made sure the coolant temp sensor is still working properly? That's what I would replace first. Also check the connector on the harness for it as they can get corroded and cause the same issue.

[talk2elk]

I think the temp sensor is functioning.... had overheating problem that started me down this road. Idle problem started same time as overheating. Had the heads magnafluxed, resurfaced, and tested at machine shop. Think they may have been warped cuz overheating went away.... I will check all connections now that I have it back from the shop. thanks

[MilesFox]

make sure the idle air control valve is working. It is the cylindrical piece on the front of the throttle body. There is a hose that leads from it to the intake boot.

 

try pulling off the hose after starting and see if the idle goes up.

 

This valve is supposed to open to introuce a false vacuum leak to make the idle go up, then close when warm. Think of it as an electronic choke for the fuel injetion.

 

chances are it is gummed up and the plunger inside is sticky. Try soaking it in sea fom. It is easy enough to remove and bench build/clean. Remove the alternator to get at the 4 screws.