Fred Anarat

Hi everyone
Yes I'm a newbie, no I aint got a thick wallet (for now), No pic's at the moment (4Runner is in the body shop aka. Fred's garage) and I'll probably ask more questions than thump my chest, But I Love my 4Runner and do 90% of the work on it myself.
Got a problem, and I need a little insight. My rig is a 1990 2dr. SR5 with a 22RE that I bought used, and it's got an erratic idle. After warming up it will sometimes rev up from 750-1500rpm and stay there, other times it'll cycle from 750-1500rpm over and over, and yet other times the idle will drop from 750 to 350rpm and stay there. I've been told that it's probably a gummed up throttlebody (I'll be checking that out this weekend), Or a leaky head gasket (I really don't want to pull the head right now).
When I adjusted the valves I did notice that the head gasket at the front of the motor was folded down into the overhead cam chain well. Is there anything else I should be looking for?

Great site,

Fred

Paul H.

Welcome to the forum Fred. The only thing that I could thinl of would be a clogged pcv valve. Maybe one of the more experienced mechs on this board can chime in.

BTOWN4RUNNER

I had a problem with an low idle, and it turned out to be clogged injectors! I added some Chevron Techron and everything came out ok. Maybe give that a try! By the way, welcome to the site! :fireman:

doink

cant really help you out, but just wanted to say welcome to the board. alot of helpful people in here. they dont hesitate to answer dumb questions...me being an expert in that field.

-m

toyota_mdt_tech

From one newbie to another the first thing you need to do is to fully clean the throttle body, everything you mentioned points to TPS out, but it may be out as a result of the plate hanging open, and also possibly base idle is too high, after it fully warms up, set it to specs.

asudan96Runner

Any chance this could be a vacuum leak? I had this problem on my Honda Prelude, and when I found the leak everything went back to normal.

Dan

Fred Anarat

Just wanted to thank everyone who responded to my original post.
I ran a can of injector cleaner, it didn't help the problem, but I've got more power now. Checked the pcv and replaced it (plugged), but that didn't help. Checked all the vacuum lines, no leaks. The throttlebody was just gross, black goo and carbon, so I cleaned it as best I could with carb cleaner, but without removing it, that only helped a little. I tried to set the idle after it's warmed up but it still seems eratic (without surging). I did notice that the entire intake plenum was as gross as the throttlebody so I figure it's time to open it up and make it like new again.

Keep ya posted on how thigs go
Thanks again.

Fred

BTOWN4RUNNER

Well, there is a plus to everything, even a bad thing! Did you use Chevron Techron? :fireman:

HBoss

Hey Fred, welcome!!

I've never had that problem on my 4Runner but I used to on my MR2. It went away after they changed my head gasket and thermostat.

You might want to double-check recalls for your year 4Runner. I vaguely remember 'head gasket' being a possible item, but I don't remember 'for which year 4Runner'.

Al

Cobb

the HG recall was fro the V6, not the 22RE. does the 1990 22RE have the late model intake, or does it still have the idle air valve?? i know my truck was having some serious idle problems, and the dealer replaced the air valve that's located under the TB. runs fine now, except for the fact that it has not power, but i guess 230k miles will do that to a motor.

welcome to the forum, and i'm jealous of the 2Door 2nd Gen you own, very nice rig.

QuattroDave

Your symptons sound exactly like the ones I have gotten when I either had a vacuum leak or a bad throttle position sensor - on several vehicles, not just Toys.

TPS can just go bad with age. If they're not too expensive, it's not a bad idea to change it pre-emptively. Dunno 'bout a Toy, but on a high end Audi, it's a $60 part, and adjusting it is done with an ohmmeter and screwdriver.

Vacuum leaks can drive you buggy. One way to look for them is to use a can of spray carb cleaner. Get the engine running, nicely warmed up. Now, spritz the carb cleaner at any suspected areas. If you find a leak, the idle will either go up or down. It will go up, if it's a small leak, and the carb cleaner seals it. It will go down, if it's a big leak and the carb cleaner gets sucked in. It will do both sometimes - first up, then down.

Head gasket? Could be - I've never had quite these symptoms from a head gasket. Look for signs of water and oil mixing. If water gets into your oil, the oil will develop a light brown foamy substance on top. That can be cause by cracks in the head or block, or a bad head gasket. Most likely the gasket. Usually, you don't get oil into the water. This is because when warm, the water system is pressurized, and so the water forces its way into the oil.

Bad head gaskets are very often intermittent. Problems one day, good behavior the next. I had a 4 cyl Honda once that behaved properly most of the time, but about once every two months, it would dump ALL the water into the oil in a few minutes. The first symptom I had was that the car just stopped. The overheated engine (neither the idiot light nor the temp gauge showed anything wrong) would just stop. I don't know if it lost compression, or if the valves failed to close because some metal part expanded too much or what. I could let it cool for 5 minutes and restart. But guaranteed, I would open the radiator, and it was bone dry. I could never figure out where the water was going until my next oil change, when the total fluid in the oil pan overflowed my oil drain bucket and ran down the street, and it was mainly green. I had the head gasket changed, and the car went fine for 50k miles until I sold it.

Good luck.

Dave

Fred Anarat

Don't find a lot of Chevron products up here,,can't remember what it was,,,mighta been STP. In any case it made a noticable difference.

Fred

Hey I'm not a "Junior" anymore when did that happen?

Fred Anarat

Well thats another problem fixed.

I ended tearing the EFI off/apart this weekend and cleaning it out completely, man what a difference!
After re-setting the idle, everythng seemed to be normal untill I drove it, I've never heard that much ping ever. I checked the timing and it was set at approx. 18* BTDC, once that was retarded to about 8* BTDC all is well. The last guy that owned this Runner sure left me with a lot of extra things to fix, but at least I'm grtting intimate with it (the girlfriend is getting really jelous!).