linuxrunner

ok, i have been searching through posts for the last year about this bad idle and have tried alot of things, i thought i might ask if anybody has any ideas.

Symptoms: The truck now likes to idle anywhere from 200 rpm to 1000+ rpm and shakes so bad that the last 2 cd players i have had cannot play cds. (VERY big shakes) Has very little power and even shakes at higher rpms, basically shaky under 3500rpm

First things that i have replaced in the last year with new toyota parts,

o2 sensor
TPS
Alternator
All new pulley berrings (just because they were loud)
new plugs + wires NGK
new air filter

Things that might be help full to know:

When i try to adjust the timing with the light it wonders back and fourth from 0 to 10 degrees btdc in the span of 2 seconds.

Adjusting the air mixture control screw helps bring idle up for the moment only and still just as shaky.

Likely has a vacuum leak (i can hear a hiss if i stick my ear close to the intake) but i am not sure how to pin point it.

EGR valve is missing a bolt where it attaches to the intake (looks to be broken off inside the intake and i am not sure how to remove it)

The screw to my dashpot is missing so i have no dashpot


IF any of these things might obviously cause a bad idle let me know. I am courious about the timing thing.

ovrrdrive

I had a vacuum leak once that I couldn't find...

I went to Harbor Freight and bought this stethoscope:

http://www.harborfreight.com/cpi/cta...emnumber=41966

And then I modified it by cutting the hose above the rod and making a Y connection out of some old hose I had laying around with some crazy glue, then attached another hose about 12" long to the end of that. With my modified stethoscope I was able to find the leak in 30seconds.

You could probably hold a piece of garden hose to your ear and do the same thing...

20005spd

have you cheched your timinig chain to see it it jumped teeth? this will cause many problems with idle, power, etc....

you should never touch the idle screw, there is something wrong that needs to be fixed and its not the idle screw, so put that back to stock location if you can.

to check for a vaccum leak an easy way is to have a lil tank of propane and slowly inject a smalll amount around intake maniold gasket, throttle body gasket, pretty much any where you could have a vacuum leak, if the idle goes up when you inject @ a certain area then you have pinpointed the leak. also check all your hoses.

the egr valve bolt sholdnt be causing a problem unless its leaking. something tells me you were screwing with that as wel if you broke the bolt. you are going to need to drill that out, have fun.

dashpot?!?!?

YotaJunky

Was the TPS adjusted according to spec? If not, you may not be able to adjust your timing correctly.

Troy

20005spd

great point troy. if the tps was never adjust properly than, do it. it seems this might be a lil out of your ability, no offense. just make sure its done corectly.then check the things i mentioned.

timebandit

Only time I have seen that is when the plug wires are crossed. That vacuum hiss can be found with a can of starting fliud or WD-40-

linuxrunner

i'll try the propane today. It wasn't me that broke the bolt on the egr valve, i just noticed it when i took it off to clean it. Since when i got the truck the idle screw was pretty much falling out i have no idea what the "stock" setting is. Any ideas about the wandering timing marks?

Also the TPS was installed by a shop that i trust so i am sure it is adjusted better than i could ever do myself. And i have checked the plugs like 5 times, they are in the right place. Although when i pull a plug the rpms drop, but it does not shake any worse... so it pretty much shakes like it is running is 3 cyl all the time, but i know all cylinders are firing and the engine only has 40k on it so the compression is great.

4Crawler

iTrader: (3)

Don't assume the shop adjusted the TPS properly. Wandering idle is often a sign of an improperly adjusted TPS:
http://www.4crawler.com/4x4/CheapTri...roubleshooting
You can easily test it yourself and either eliminate the TPS as the cause of the problem (if it is adjusted properly) or point to the TPS as the cause of the problem.

linuxrunner

Just checked the TPS and it looks like it was right on. Also if i jump the timing check connector the engine does reduce idle and return to base timing. For the most part the timing wanders when the idle is VERY low and the engine is extreemly shaky.

4Crawler

iTrader: (3)

Well that eliminates the TPS. See if the EGR is sticking open, try tapping on the valve when it is idling rough and see if it clears up.

deserttoy84

my freinds 1990 4 runner is have idel problems. We did the wire jumper using the sticker under the hoods instructions. it didnt change the timing. the timing also jumps liek 2 degrees so it hard to tell. but i set it and 5 degrees leik it said and it knocks a lot under a load now and when he started it cold, it had a miss. I will check the tps tommarow, but what is the proper way to time a 22re? also is the check engine light supposed to flash at all when that wire is jumped? I dont knwo how many times it flashes but it does at least a few.

4Crawler

iTrader: (3)

Flashing light is likely due to stored trouble codes:
- http://www.4crawler.com/4x4/CheapTri...CheckConnector

Test out the TPS to make sure it is set properly:
- http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

Then go back to the timing procedure, you should see about a 7 degree change in base timing with the insertion of the test jumper.