1986 4runner engine will not idle please help!

Try checking the TPS and IAC too. I just went through all of this myself. Ended up being a small hole in the return line from the charcoal canister under the hood to the fuel tank. Now it runs like a top.

Keep posting what you have checked out and we can suggest other things to try.

Good luck.

 

Yes checked that and there is pressure. I also pulled off the throttle body again and cleaned up the inside and the flap real good thought maybe it was sticking and causing the issue but still no help with keeping it idle. I am now checking all sensors that would possibly cause this issue.....anyone have any ideas at to if a sensor would cause this and where to start? ?

 

Try to clean and check the TPS(throttle position sensor) an mass air flow sensor, with the mass air pull it out your air box if you can and clean with brake cleaner.

So no idle when engine cold or hot(warm)

Do you have a RPM gauge? If so what's the lowest it will run when you feather gas to keep it idle, running?

 

I don't have an rpm gauge in mine. So I'm not sure how to go about letting you guys know where it idles when I feather the throttle. And no it wont idle at either engine temp hot or cold. It started having this issue where I had to crank it about five times and kinda rev a little to keep it to idle before I replaced the head and all the new parts.

 

You could try and post in the technical part and maybe get a little more feedback. I'm not really sure. Have you checked the TPS? You can use a ohm meter and see the range it's putting out. Should change as gas is pressed between a certain range.

 

This afternoon once I get off work I am going to be checking all sensors I haven't checked them yet just trying to rule out bad gaskets or bad vac lines first.

 

Alright checked my MAF sensor even had two spares and plugged them all up and I can hear the flap and see it open when cranking but then after it starts it wont stay engaged. If you stick a screw driver in and hold the flap open the 4runner will continue to run and idle real smooth. So my question is does anyone know what would cause the MAF sensor from engaging properly? Is there a fuse for it or is it run by the computer?

 

I had a friend back in the 80's who had a Ford Escort that did the same thing, the car would run perfect, but would not idle at all, it ended up being the ECM, the program forgot how to idle. I know in the 86 4runner they also have an Engine Control Module, you may want to check that out, its easy to short out. Good luck in finding the trouble!

 

Alright little update after installing a different ECM and 2 different AFM the truck will not idle still. However if you move the flap that is inside the AFM it will run just fine but if you let go of that flap it will stop instantly. Is it possible for an ECM just to forget how to idle? And what are the chances that @ ECM's are bad and 3 AFM's are bad as well?

 

very slim, probally something else, i never did see, have you messed with the TPS yet?

 

No would that cause the AFM to not want to engage?

 

not sure, have you tried to check and see if the AFM is getting any time of current, maybe the wire to it is broke???

 

I will double check and see but I am sure that everything is hooked up a friend of mine that has gone through a bunch of these engines is helping me and even this has him stumped as to why it was running great with the bad parts and as soon as we put the new parts on it runs like this. But we have double checked every connection that we unplugged but I will look and see if we left something out at the AFM.

 

These kind of problems suck, I wish you luck in finding the solution, it's this kind of thing that can drive you nuts. I looked around the net and this guy had the same problem and ended up solving it, may be worth looking into!
http://www.yotatech.com/f116/1986-4runner-22re-rough-idle-rich-no-power-213202/index7.html
Best of luck!

 

Thanks for the help I also found that guys post and my friend had an extra ECM that matched mine in one of the 4runners he has we tried swapping and still no idle but not sure if that computer is bad as well or not and I don't really have the money to take a gamble on purchasing a new one and then it not solving my problem. But guess I have to do what I have to to be able to cross things off my list of what it isn't.

 

You shouldn't have alot of air coming from the oil fill tube. You might have a broke ring on the piston... Have you done a compression check? Reason I know this is my sts turbo camaro was doing the same thing and wouldn't idle.

 

Ok I'll give it another check today between work, class, and daughter being sick this week has stacked itself up pretty good. I will see if I can't find someone to run a compression test for me.

 

Best of luck in finding your problem! When I have more free time ill see what I can dig up. Saw something about a Idle Control Valve on a 4Runner having caused issues, if I find the link again ill post!

 

No luck with anything I jumped the e1 and te1 and read the check engine code and it's reading 1. A/c switch 2. Throttle position sensor 3. Throttle position circuit 4. ECM

I've never had a/c in this truck it has it but doesn't have a belt on the compressor so i've never hit the switch for it.

 

Does anyone have any knowledge on how you check to see if the ECM has gone bad? I think its the TPS that's gone out but a friend of mime had his doubts but before I sank some money into a new ECM I just thought I would ask.