Long time lurker, lots of great info here and I appreciate the forum and community.

I am having an intermittent idle issue with my 1987 Toyota Pickup with the 22R. I will occasionally go days or even weeks with no issue, but occasionally I will have an issue where the truck wants to die when idling. Sometimes while sitting at a stoplight, other times it will be as I depress the clutch coming to a stop and the revs drop to idle. I can normally keep it from dying if I give it some gas, and sometimes it will limp along at idle with no throttle. If it dies, it will always restart immediately, but will likely require a bit of throttle to keep from dying again.

It will only ever happen when the engine is warmed up, and there is no consistency when it occurs after the engine is warm. Sometimes I can drive days at a time with no issue, other times like today, I drove roughly 2 miles, idled for 15 minutes at a drive through, and then another 7-10 minutes waiting in traffic at a light when while idling at 900 RPM, it suddenly started idling rough and required a bit of throttle (1100 RPM or so) to keep it running. When the issue starts, any off throttle in gear while moving results in missing / small bucking until throttle is applied. Will mostly last 5-15 minutes and then it will be perfectly fine again, with nothing else done to change the issue.

Given the random nature, I suspect something electrical (already checked that plug wires are connected firmly) and I have inspected the emissions control module and found all the solder points to be in good condition with no cracks. I also suspect the fuel cut solenoid as the truck will occasionally diesel when shutting off. However, I don't want to remove or ground out the fuel cut solenoid unless absolutely necessary because then the truck will likely diesel all the time, which I have heard is not good for it. Also, it never completely cuts the fuel, as it seems like only one or maybe two cylinders are still working normally. Checked plugs and they are gapped and look normal.

Any other suggestions on what to check would be much appreciated. Nothing worse than a intermittent issue to try and troubleshoot!

 

Has your carb been rebuilt? You could try a new o ring for the fuel cut solenoid since you mention it's dieseling on shutoff occasionally. O Ring Part # 21655-44101. Or get a carb rebuild kit for the o ring if carb hasn't been rebuilt, just in case...

 

Thanks for the reply. The carb has not been rebuilt, but wouldn't a bad fuel cutoff solenoid o-ring cause issues all the time and not sporadically?

 

I agree, you'd think if the o ring was bad the problem wouldn't be intermittent. I've read other posts where people had intermittent idle issues and the problem was either cracked solder or bad connector issue with the emissions control box. You've checked that so I thought I'd throw out the o ring replacement since you're having intermittent dieseling. The o ring may not fix your intermittent idle issue but it may fix the intermittent dieseling.

 

I checked the o-ring, it is is good shape.

I wanted to avoid cutting and splicing wires, but I cut the fuel cut solenoid white wire and spliced it to a ground on the frame. So far, so good but only time will tell if this is indeed to fix. I will update for those who have a similar issue.