87 2.9 shakes and stalls when cold

[King24]

I have a 87 2.9L that just refuses to run right when cold. I drive it back and forth to school 5 days a week. I live about 5 minutes from my school so it never really gets time to heat up. Every morning I go out and start it up, sometimes it stalls, sometimes it shakes, and I have to rev it to 2,500 to even get the clutch out without it stalling. On my way back from school it's not nearly as bad, starts, Idles, and I only blip it to about 1,500 and it sets off perfect. Any ideas on how to fix this problem? Plugs are relatively new, less than 3 mo old, air filter is a aftermarket Spectre one. This is only my second car and my previous was a civic so I don't know all that much about these engines. Thanks in advance.

 

[Paulos]

If it only runs like this when it's cold, I would check the IAC valve. It's the device mounted on the side of the upper intake (in the picture it's just to the left of where it says "2.9L" on the intake) and has a two wire connector. It sounds like it's stuck in the closed position or clogged up.

With the engine cold and running, unplug the connector. I suspect that it won't make much (if any) difference in RPM. Maybe it's just clogged up and you can clean it with carb cleaner. If you remove it to inspect/clean it, make sure the ports in the intake (where the IAC bolts to) are clear also.

 

[PetroleumJunkie412]

Damn good engines all around. After you get your blip tackled, run a can of the aerosol sea foam through it according to the instructions, and go for a long drive.

 

[King24]

Thanks for your replies, I did some investigating which led me to find the IAC was completely unplugged, reconnecting it caused a rev spike to over 2500rpms. I usually thoroughly look a car over before I even think about buying it, but this was an exception since it was a gift from my grandfather. A quick call to him and I realized that he had unplugged it years ago since it failed and Autozone wants $60 for a replacement and he said it ran fine without it. He is not big on online shopping so he was very surprised that I found a brand new replacement for only $23 shipped. It will be here in a few days and I will update the results. Also I did just that with the seafoam and went for a drive, however the truck decided that day was the day it wanted to overheat so my drive was cut short. I was admittedly driving it much harder than usual (5000 rpm shifts) to get the seafoam to clean everything out, but I think I pushed it a bit to hard. I pulled over and let it cool for about 4 hours, refilled the rad and nursed it home. After a coolant flush it was apparent why it overheated, the coolant was all gummy and nasty. At first I worried that I blew the head gasket but we flushed it and now has clean coolant and the oil has zero coolant in it so I guess I got lucky. Anyways thanks again guys.

 

[Paulos]

Thanks for getting back to us and letting us know.