I have an 86 22re 4runner that has a bad (getting worse) miss at idle that goes away at higher rpm. I have changed the plugs, wires, rotor, cap and coil. I am going to check the vacuum lines, egr, o2, maf, and tps as soon as I get time. My symptoms sound like several that have been solved by replacing or repairing one of those, but while I was searching here I found a few links that say that coolant problems can be a cause too. I have a couple of coolant line leaks so could these be causing air in the lines/bad readings that will cause these problems? It has never overheated and there is no coolant in my oil or vice versa I just have to top it off every now and then. Thanks in advance for any help.

 

Checked your timing and the bolt that holds the distributor from turning? Hows your timing chain? Edit: and your fuel filter and fuel pressure?

 

Replacing the fuel filter tomorrow and I will make sure to check the distributor bolt when I do that. The fuel pressure check and timing check are on the list too just forgot to put them in the original post. For that matter I am going to go through the efi system and do the code check procedure that is described in the fsm. This is all new to me so I wanted too make sure I am not missing anything hence the coolant question.

 

At least you know what a FSM is and how to use it. Your a step ahead already! Good luck.

 

Thanks I was lucky that the previous owner had a fsm and included it in the sale along with most of the gaskets and seals that needed to be replaced. It seems like I have read the whole thing in the last three months. With that said is there any truth to cooling system issues causing similar symptoms or am I just chasing my tail there?

 

That is a question i truly cant answer due to the fact that i have not experience it myself yet nor have i read anything about it. Hopefully someone can chime in with some good help in that department.

 

I believe i am having the same symptons. And im 99% sure its caused from coolant. Your truck gets air pockets and dosent read the corect temps. So its stays in its closed loop.

 

Thanks for the quick responses anyway and anyone else that has any knowledge or even a link it would be greatly appreciated.

 

Just saw your post Tyler and that's what I was getting at. Do you know what sensors cause that? Mine also hasn't been idling up on cold start since the stumble got worse which I assume is related but I'm not sure where that points me.

 

anyone else got any insight?

 

I think your IACV has the biggest role in the idle problems. What i think in mine is the air bubble/s go to the highest point which is the IACV and starve it from coolant. So that makes it idle wierd. Mine leaks about a quart of water a week. Mine will act really wierd when its hot. If i start it it will try to die i have to feather it for about twenty seconds. I believe when im feather it that just moving coolant around and moving the air bubble.

 

Sounds like what I have going on too gonna add the IACV to my list.