22RE Sudden Very Rough Idle

[TerryC]

'87 4Runner, 22RE FI.
Couple years ago, drove to salvage yard, about an hour away. On the way, thought I'd 'treat' my nearly 300k motor to Rislone. Added about 1/2 qt. Just before arriving at the yard, my engine suddenly lost power and began to idle very roughly. Couldn't see the cause, drove it home with lots of people giving me angry looks for driving so slowly. Parked for two years while I worked on the car I'd gone to get parts for.

Today, back to the 4Runner. I thought PCV valve should come right out but it doesn't want to so I pulled the rocker arm cover. PCV valve rattles as it should. Chain and distributor look fine, far as my eyeballing can tell under the cover.

EGR valve filters are dirty but that's no shock. Air filter is very dirty. If I uploaded correctly, you can see my plugs. Some oil is getting to them, but I see nothing shocking. So far, I see nothing to explain sudden rough idle but my thought is that it might have something to do with the Rislone, which, I think, leaves an oily film.

I think I'll run out to get plugs, wires, air filter, EGR, it's their time anyway. Also thinking it's time for me to look at injectors, a mystery to me as I grew up in the era of carburetors. Thinking maybe some sticky Rislone got pulled through vacuum lines.

Any ideas, suggestions? The thing that has me confused is the sudden loss of power and very rough idle.

 

[raevenzero]

I would check every bit of the intake plumbing for cracks and holes. Also make sure that the afm flapper is moving freely. Fuel filter could be plugging up. I had a leaky injector that caused the truck to run like crap too.

I used to hear a lot about the tps going bad but I never had that issue so I can't say much about it.

Just some ideas.

 

[TerryC]

Thanks for the reply! I was starting to wonder if there's anyone else out there. I appreciate the thoughts and will be looking into those possibilities later this week in the evenings.

If anyone else has theories, let me know. It's just odd that it'd happen so suddenly. I'd have expected something more gradual and I think that the sudden loss of performance is the key to diagnosis.

Thanks, again. I'll update if I figure it out, in case it helps someone else someday.

 

[raevenzero]

It's been slow around here lately. About 6 years ago, I had my intake pipe get into the fan. The fan won and there was a small hole in the pipe. I could barely keep it running and I had no idea that the hole was there. Any unmetered air causes thes things to run like crap.

Another story is that I had a sticky AFM once and only when I hammered the throttle down would it suck open and work fine, when it returned to idle it would get stuck again. When I figured it out I thought "Really? That's what made this thing do that the whole time?"