idle issues

[high4runner]

first time posting here so i'd like to say hi to everyone....anyways here is my issue. i have a 92 80 series, straight 6 auto. has about 200,000 miles, 60,000 on rebuild....so here goes....truck seems to idle high to begin with....i'm gonna say 850-900 in gear...sometimes it will go down to 500....but the idle seems kinda rough...even though the tach isnt jumping around at all. while im driving the truck runs smooth...but after driving down the freeway when it comes time to stop the truck seems like it wants to die...atf temp, brake, and alt. lights come on and idle is way low and rough....but once i get on the gas whammo...it runs good again...never had it die on me yet...and never had any problems starting either. in the glove box i found a letter talking about the efi wire harness being bad and that toyota makes a replacement. called toyota parts dept. and they didnt know what the heck i was talkin about?? so then i go look under the hood and i see out of the main relay box a wire harness going to the front, across to underneath the batt. tray and a couple wires commin straight up to the possitve terminal of the battery....is this the replacement wire harness i am seeing?? this truck is fairly new to me so i dont really know anything about it. most the work i have done is on my 84 toyota rock buggy project. another note....when shifting into gear it seems to kinda clunk....drive line and rear end seem tight...i dont know if its just because the idle is out of wack or what? thanks for your help guys...

 

[high4runner]

c'mon...there has to be a few guys with 90-92 cruisers in here??? anyone else ever have this idle issue??

 

[firetruck41]

While your waiting, have you checked the 80 series Faq? I don't know if your idle issue is covered, but it could get you started on learning about your rig.

 

[Jason Andrews]

Driveline clunk is normal. With the lights coming on in the dash and such I would check to see if your alt or battery is bad. Low voltage can cause all types of seemingly unrelated problems. When my alternator went bad it fried my headlights, no blown fuses and it still started everyday and I drove it for another month before I got it fixed. Also check on that EFI relay. I don't know much about it tho. Good luck and Welcome

 

[high4runner]

yeah i took a look in the faq section...couldnt find anything...as far as the alt. being bad i know the dash lights i mentioned will come on if the alt. is bad.....but would it cause the idle to be messed up too?? just seems like the idle is high 1200 in neutral, 900 in gear...even after the truck is warm it doesnt drop down...every once in awhile it will go to 500 in gear and 800-900 in neutral...but the sputering and allmost stalling after long drives is what makes me nervous. anyone in here ever change the relay wire harness? pics would be helpfull just cause i dont really know what im looking for. and thanks again for you guys that take the time to post back and help me out here

 

[Ross IV]

the wiring relay i think you are talking about is probably unrelated to your idle but if you call Dave at ULC in ATL he will talk to you about whats goiing on. as far as the thunk goes that is just going to be there, everything is fine never fear it's a Land Cruiser

 

[high4runner]

yeah i love this truck!! ever since i had my first toyota truck i have loved em! they have never let me down on the trail...once i can get this idle issue figured out i'll drive this bad boy every where!! im even thinking of selling my 84 ex cab toyota rock buggy just to trick out my cruiser.

 

[akcruzers]

first time posting here so i'd like to say hi to everyone....anyways here is my issue. i have a 92 80 series, straight 6 auto. has about 200,000 miles, 60,000 on rebuild....so here goes....truck seems to idle high to begin with....i'm gonna say 850-900 in gear...sometimes it will go down to 500....but the idle seems kinda rough...even though the tach isnt jumping around at all. while im driving the truck runs smooth...but after driving down the freeway when it comes time to stop the truck seems like it wants to die...atf temp, brake, and alt. lights come on and idle is way low and rough....but once i get on the gas whammo...it runs good again...never had it die on me yet...and never had any problems starting either. in the glove box i found a letter talking about the efi wire harness being bad and that toyota makes a replacement. called toyota parts dept. and they didnt know what the heck i was talkin about?? so then i go look under the hood and i see out of the main relay box a wire harness going to the front, across to underneath the batt. tray and a couple wires commin straight up to the possitve terminal of the battery....is this the replacement wire harness i am seeing?? this truck is fairly new to me so i dont really know anything about it. most the work i have done is on my 84 toyota rock buggy project. another note....when shifting into gear it seems to kinda clunk....drive line and rear end seem tight...i dont know if its just because the idle is out of wack or what? thanks for your help guys...

Have you checked the truck for trouble codes? Sounds like you have a cold start switch thats bad or have a vacuum leak. Check the diaphram on you're EGR valve this will cause rough idle at start up. Check ALL of yo're vacuum lines.

To check the codes.

truck at operating temp
jumper wire between TE1 and E1 at the diagnostic port in engine bay
trans in neutral
turn key to RUN position (Not Start)
count how many times "Check Engine" light blinks. It will blink two times then there will be a pause and blink a number of times after that. The first two will corispond to the number two and after the pause the number blinks will represent the second number. Put the two numbers together and check the FSM for the codes, or post here and somone will look it up for you.
If the light blinks steady then no codes are recorded

Good luck,
G

 

[othater]

I had similar idle issues and I cleaned the throttle body and it cleared my idle problem. Mine is a 94 though.

 

[high4runner]

i'll try checking engine codes...i thought that the check engine light would come on if there was a problem?? only time it comes on is when motor is cranking over (same time as when all the other dash lights come on)

as far as cleaning the throttle body...what is involved in doing that?

 

[high4runner]

Sounds like you have a cold start switch thats bad or have a vacuum leak. Check the diaphram on you're EGR valve this will cause rough idle at start up. Check ALL of yo're vacuum lines.


i know im dumb.....but where is the "cold start switch" and the egr valve?
allready gone through and checked all the vaccum lines

p.s. idle isnt rough at start....my concern is after driving 30 miles or so when i come to a stop it wants to die on me... i just mentioned that the idle doesnt seem smooth while im in gear, stopped, just so you guys get all the variables involved in my trouble shooting problemo

 

[Romer]

do you know if it has had a tune-up recently. New rotor, dist cap, plug wores, plugs, fuel filter PCV valve. Any one of those could contribute to an idle problem.

 

[Uncle Ben]

do you know if it has had a tune-up recently. New rotor, dist cap, plug wores, plugs, fuel filter PCV valve. Any one of those could contribute to an idle problem.

Does the engine idle up if you turn the A/C on? Sounds like you might have a ISC valve issue. (Idle Speed Controller) On a OBD1 vehicle it might not throw a code unless it is an open circuit. The referance to the EFI wiring usually pertains to the 1FZ engines (you have a 3FE) as the harness passes right by the base of the EGR valve. When the engine was rebuilt were the injectors replaced or cleaned?

 

[high4runner]

Does the engine idle up if you turn the A/C on? Sounds like you might have a ISC valve issue. (Idle Speed Controller) On a OBD1 vehicle it might not throw a code unless it is an open circuit. The referance to the EFI wiring usually pertains to the 1FZ engines (you have a 3FE) as the harness passes right by the base of the EGR valve. When the engine was rebuilt were the injectors replaced or cleaned?

a/c doesnt idle up....just checked the trouble codes....no codes came up....as far as the injectors being done i dont know...the reciept i found in the truck was for a jasper motor...dont know if it was rebuilt-or a re-manufactured or what. from what i can see all the vacum lines are right and intact. now i found another issue...i wanted to play around with the 4wheel drive so i pressed the CDL and no light came on...worked a couple days ago...even going into 4low the light didnt come on...i know this is irrelevant to the subject at hand but you guys can answer this one too...lol
oh and as far as a tune up....i have only had the truck a couple weeks so i havent done anything like that to it....maybe i'll go pull a plug right now just to see what it looks like.