Today I decided to clean the Air Flow sensor on my 90 22re and ended up taking the intake tube apart to check out the Throttle body which has been a little sticky. Holy S***! The Throttle body and intake were all coated in about 1/8" or more of black oily residue. Took off the Throttle Body and cleaned it out. All of the little ports next to the Butterfly were plugged. Cleaned out what I could of the intake and put it back together. Runs great, nice smooth idle etc.
My question is this, is it normal to have that much residue build up over 20 years? Or might there be something else going on? Thanks for any ideas.

 

Haha nope thats normal if the throttle body was neglected like most are.

 

Thats a DIRTY intake! Dirty dirty dirty! Naughty INTAKE!



Oh sorry got carried away

 

Yeah, I figured. I bought it off a friend a couple weeks ago and I'm going through it a little at a time. He's one of those "fill it with gas, take it to jiffy lube and go" kinda guys. No offense if you work at jiffy lube.

 

Ha! Dirty Girls, OK. Dirty intake not so good.

 

haha my buddy works at jiffy lube....I've heard some stories...its not good

 

Drove it to work this morning, about a 40 min. drive, now it idles up and down when I come to a stop and have my foot on the brake. Weird. I'm searching forums but if you have any ideas let 'em rip. 1990 22re 4x4 with A/C. It used to do it only if I had the A/C on, but now does it regardless.

 

Did you take off the TPS when your cleaned your TB. If not you might need to readjusted it or your fried it. Always take off your TPS when cleaning your TB. Search on here and you will see why...

 

I have never taken the TPS of for throttle body cleaning, nor do I recommend it if it is working properly.

Unless you like fixing things that aren't broken and like wasting time

 

Search "black goo"

it's very common; I had a run in with it myself many moons ago

https://www.yotatech.com/forums/f116...thread-142091/

 

Wow, I guess if you never clean your throttle body haha I don't think I have ever seen one that dirty in my life!

I'm guessing the PO didn't keep up on maintenance, eh? Thanks for that link, I guess if your throttle body looks like that, I would disassemble everything on there and scrub it lol

 

Thats what I saw when I opened up my throttle body!
I did not take off the TPS when cleaning.
It runs fine up until its warmed up and you step on the brake pedal.

 

prob has something to do with the brake booster..just throwin that out there

 

Or low on coolant/air pocket in the coolant.
Or idle speed is too high now, and timing is off
Or vacuum leak after you put it back together.
Or TPS is out of adjustment/damaged.

In that order.

Why does it do that? When the idle is at or above 1000 rpm and you step on the brakes, the ECU, more often than not, "thinks" "hey, this guy is slowing down, so I'll cut fuel" then it does, and the rpms drop. Then its like "Hey, maybe hes not, so I'll add more fuel again". over and over, causing the rpms to surge.

 

Yeah, I agree. I'm going to have to go through everything that could have been affected by cleaning the throttle body. Vacuum lines, air pocket in coolant, tps wasnt taken off but could have been affected. Its weird that it did it before only if the a/c was on and now it does it after warming up. I can't work on it till after 4:30 and its bugging me.

 

Fixed, my idle was a little too high and the ECU was trying to compensate. I had turned the idle speed adjustment screw out previously to get the idle smoothed out. After cleaning the throttle body it needed to be turned in about 1 1/4 turns.
It still idles up and down when the a/c is on and I have the truck in neutral with my foot on the brake so I still need to chase down that problem.

 

I have the same problem. Had a dirty intake and cleaned it out the other week. Had the idle problem since I bought the truck last summer and never really had time to get into it and tear it apart. Mine only does it when my foot is on the brakes, it also has a real high idle on start up. If I start it and mash the brakes a couple times the idle will climb all the way up to 2500rpm all by itself.

Still not really sure what needs to be fixed and I kinda would like to know before I tear it apart and guess whats wrong cause I need it daily and need minimum down time.

 

I ended up looking into the brake booster line first, because the brake had an affect on the idle. The check valve was a little sticky plus I got some Copenhagen in it so I sprayed WD40 through it and it loosened up. I also worked the hex screw on the a/c idle up back and forth and removed it to check if the intake goo had plugged it but it was good. Checked all vacuum lines. Adjusted idle speed screw on throttle body and now it idles fine unless a/c is on.

 

how high is your idle with AC on, in neutral, without stepping on the brakes. It could be doing basically the same thing, only the idle is too high with the AC on. You know where the AC idle-up screw is, correct? Try turning it down a little.

 

All good now, turned it in 1/2 turn and it brought the idle down just enough to stop the problem. Thanks everyone for your input.