Anyone out there know what this could be? I'll start up my '89 3.0L, it'll run fine for about a minute then it will start idling weird. It's hard to explain. It kind of lopes for about 5 minutes until it warms up, then it smooths right out and idles fine. After about 10 minutes of idling, it starts to overheat. I changed the stat............no dice. Removed the stat.............no dice. What's next fellas? Thanks in advance for the help.

 

I have the same problem, minus the overheating. When I first turn it on it sometimes revs itself for about 30 seconds to a minute and then smooths out. Strangest thing...

 

Mine too but only the first time I start it or if it sits for a while. I'm thinking it may be the cold start injector since its gotten worse now that the temps have dropped.

 

You're probably right, I'm wondering if thats a significant problem, or if I can just deal with it until it warms up again.

 

If you're serious about fixing it get a paper clip and check the error codes yourself. Then reset your system by disconnecting the battery. Recheck your error codes and see whcih ones are current and recurring.

Off the top of my head I'd ask these two questions first:
1. Did you check and make sure you have enough fluid in your radiator? Is your overflow topped off?
2. Have you cleaned your injectors lately?

My 88 4runner had horrible idling and it was because the auto shop replaced a bad injector with an aftermarket one that did not work properly.

So.. check fluid, check injectors. If that doesn't narrow it down it could be an O2 sensor but everyone likes to replace those before they check the basics...

 

Check your head gaskets. Shoot some air in each spark plug hole and see if any water comes out. Broken ceramic on the spark plugs is a sign of water too.