Fambugee

Hey guys, I've been reading these forums for quite some time and appreciate all the great info. I bought my 88 about 7 months ago at 150,000. It has the22re in it and it took me all those 7 months to get her to this point. Anyway, she now drives great and is leak free. However, she idles a little rough. It almost seems like a miss where the engine just stumbles randomly and then recovers. It seems worse when it's mid day and hotter. Recently did a pretty thorough tuneup to include timing chain, wires and plugs, adjusted timing, adjusted idle (no tach), adjusted tps, replaced cap and rotor, air filter, coolant flush, oil change, water pump, all the good stuff. I cannot for the life of me figure this out. Things I've done to troubleshoot this: adjusted tps(its within spec in all parameters), sprayed carb cleaner around all vac lines and intake manifold gasket, verified all vac lines are routed correctly, tested egr (removed line, pulled some air through the egr and engine stalled out immediately). that's about it. any help would be much appreciated. the engine seems to run awesome when i'm actually driving and there's a load on it, but at idle it's just random stumbling.........help! she has to make it to yellowstone in a couple weeks oh and a pic of my baby

xxxtreme22r

does the idle change if/when your on the brakes? When you set the ign. timing did you use the jumper?

Fambugee

yeah at first i got no reaction when jumping the terminal, replaced tps and after that you can easily notice a change when installing the jumper while its running. brakes have no effect whatsoever. i'm wondering if it could be related to the afm.....guess I should probably do a compression check too............don't know.

xxxtreme22r

What did you use for a timing spec? It should be 5* BTDC with the jumper installed. Could be AFM. Any codes or CEL?

Fambugee

no lights, code free. set her to 5* btdc. also adjusted the valves a couple times until I was content with the least amount of chatter. I don't think that would affect the idle but just throwin' it out there. freakin' thing is drivin' me crazy! it's totally tolerable, but it's like that last little thing i just can't figure out.........

Fambugee

the new oil pump i put in there didn't have any marks on it so i just compared it to the stock one i pulled off and marked it with white paint. the truck definitely seems to be happiest at 5* or even more advanced. i just set it to what the book said since i didn't know if running it more advanced would hurt anything.....

xxxtreme22r

Valve lash if off can affect the idle, your never gonna get these engines quiet especially with old adjusters. I would go back and set the lash on the valves for spec and not sound. Also too tight a lash can burn valves as well over time. And the rocker cover being too tight can make noise as well because the rockers will hit the cover.

snobdds

Like said before, if stock cam adjust to spec hot and leave it.


If the idle dosen't change with the brakes applied, then I would look into your IACV. There is no need to take out the spring and all the internals, just make sure it's not plugged. On mine, the smalless coolant hoses come off of it and into the TB, so all the junk gets trapped there. Can cause weird idle issues.

Fambugee

yeah i adjusted cold initially, then adjusted them hot. it sounded horrible after the hot adjustment although i did it exactly to spec. so, i re-checked them cold and 3 of them were just a hair loose when cold. i know there are a lot of different theories on this, but i readjusted them cold to 7/11 and the engine honestly seems to run and sound great minus the idle. for the record, the idle has been doing this throughout all valve adjustments and has consistently been stumbling..........i'm at a loss............on a side note.......i bought this truck from someone who told me valve adjustment was never done..........so these valves had the stock adjustment.........the engine was super quiet........but damn they were waaaaaaay tighter than they should have been,,,,,,,,,,,so i don't feel too bad about my cold 7/11 choice

Fambugee

snobdds, can you elaborate on that? haven't heard of this.....is this an easy check?

xxxtreme22r

Not to scare you but.....if the engine went that long without a valve adjustment, I am almost positive the adjusters are bad and possibly the cam is flat spotted fro m the bad adjusters. You may or may not feel the difference when driving, but that would certainly affect the idle kind of like how a "big" cam does.

x2 on the IACV = Idle Air Control Valve.

snobdds

Below the throttle body. There should be an air hose coming off the front. A rear hose that goes to the throttle body, and another rear hose that goes to a "T" that comes off of the timing cover on the pass. side. It's held on with a couple of screws. Just make sure it's not clogged. You don't want to take it apart because it is hard to get right again. Just blow through it and see if it's pluged, if it is then you found your problem.

Fambugee

scare away, i don't know much about these engines..........i worked on turbine engines for many years but that's a completely different animal.............................so i guess what i'm getting at is, what can i do/check? i don't know anything about this IACV, so if someone could dumb it down for me that would be awesome. i appreciate all the help so far guys......

Fambugee

do i need to drain coolant or remove the tb to do this? maybe i can do it this weekend........

Fambugee

maybe i could just pull off one of those lines and put some compressed air through there to see if it's clogged? as long as i'm blowing air in the correct direction?

snobdds

you will have to drain the coolant. Take off the air intake tubing from the throttle body and you should be able to see it down below there. take off all the hoses at the IACV and unscrew the two screws. Blow compresses air through and then you will know if its pluged. Clean and replace.

It would be a good time to look up the throttle body and see if it is has carbon build up. Take some throttle body cleaner and clean up trying not to get too much into the TPS. Those two should help with the idle issues.

Fambugee

so a little update. i haven't done anything since i last posted but i did read that you could pull off the air inlet hose and inside the tb neck there is a 1/4" hole which leads to a hose that goes to the IACV. Apparantley if you put some duct tape on that and the problem improves, then something is definitely astray in the IACV system. I did this, and it didn't do anything, maybe made it run worse. On a depresssing side note. Today at about 2pm when it was hot, like 90 or so, I came out of harbor freight and started her up. I'm used to the loping and such, but the engine was actually surging now. Like going from low rpm's to high rpm's almost like a sensor was controlling it. Still no freakin' codes...........this truck truck is awesome minus this one flaw................grrrrrrrrr, i'm in the middle of a timing belt change on a civic right now so i'm bouncing between the two trying to figure this out. the 4runner has to go to yellowstone in two weeks...........come on guys any other thoughts?