Timmo760

I apologize if this is a common topic. I have been searching but haven’t found something that’s sounds the same as my issue.

recently was given an 86 4Runner from the in laws. They were original owners and just didn’t want to put anymore money into the truck. They told me it needed a timing chain. Their mechanic told them the chain stretched and skipped a couple teeth. The mother in law told me it won’t stay running so they couldn’t get it smogged (California).

so I replaced the timing chain this weekend and got it all back together and it fired right up. I was stoked. Let everything warm up and was still idling great. Super smooth idle. Once it was warm if gave it a quick bump on the throttle it will die once it comes to idle speed. Won’t want to start back up unless I give it a little gas on the throttle.

Direction on things to check will be greatly appreciated. Thank you!!

az4x4runner

How's the intake tubing between the throttle body and the AFM? Any cracks that might be letting in unmetered air? Is the problem always present only after it has warmed up?

Timmo760

Yes it only happens after the engine is at operating temp. Before that it runs perfect. Last night I did a quick check for vacuum leaks since it was something that could be going on. I didn’t find any but I need to check again more carefully.

ive been reading. So I need to check the TPS, coolant temp sensor, air flow meter,... I might be forgetting any. Am I on the right track on what could be the issue? I do have a service manual so I’m able to get the specs of the sensors


to add to your question.. even after it has warmed up it will idle great. Just when you give it some throttle then let it come to idle it will die. Then to get it started again I have to give it a little gas while it’s cranking over for it to start up again but then it will idle fine again.

az4x4runner

Those certainly are things that I would test, especially the TPS and AFM. Also a thorough check for vacuum leaks and fuel pressure.

What is the condition of the plugs, wires, distributor cap and rotor? Has the fuel filter ever been replaced?

Maybe check the operation of the dashpot and throttle opener on the throttle body per the FSM.