kmat123

I've been having the infamous surging idle on my '94 22RE pickup for the last couple of months, so today I pulled the TB and cleaned it out. There was quite a bit of carbon buildup, but with a little elbow grease and a lot of TB/Intake cleaner, she was looking like new. When I blew compressed air through the vacuum ports some gunk came out too. I reinstalled the TB with a new gasket, topped off my coolant and fired up the truck. Well, the surging idle problem is gone but now it idles very rough (sounds like a Harley). It also sounds like there is a hissing sound over near the TB now, which I don't remember being there before (vacuum leak?). I've checked and re-check that I reconnected everything, and was wondering if you guys had any suggestions?

Firefightertaco

are u sure u got all the vacuum lines back in the right places?

thook

Spray some starting fluid or use an unlit propane torch around the area.

kmat123

Yeah I am sure I got all of the vacuum lines back in the right places. That was my first suspicion, but I labeled the lines when I removed them and have triple checked they are all in the right place. I'll have to try using some starter fluid to find the leak. Also, I don't get any vacuum from the P port (3rd down) at 3500 RPMs like I am supposed to. I sprayed compressed air through that port just to be sure that something hadn't gotten in there when I was cleaning, but the rough idle persists. At idle there is a strong exhaust smell as if it is running too rich....

84sr5yoty

I hope you remove the TPS when you cleaned the throttle body. The TPS isn't totally sealed and the mixture of carbon, sludge and throttle body cleaner can kill em. Check your TPS for proper operation.

http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

kmat123

Nope. I didn't remove the TPS when cleaning my TB. It would be nice if the FSM said to remove it. I'll go test it and let you guys know what I find.

kmat123

Well I tested the resistance across terminals on my TPS and this is what I got:

0 mm clearance VTA-E2 - 0.49 K Ohms (Ref Range .47-8.1 K Ohms)

.57 mm clearance IDL-E2 - 0.01 K Ohms (Ref Range < 2.3 K Ohms)

.85 mm clearance IDL-E2 - Infinity (Ref Range Infinity)

Wide open throttle VTA-E2 - 2.92 K Ohms (Ref Range 3.1-12.1 K Ohms)

0 mm clearance Vcc-E2 - 3.66 K Ohms (Ref Range 3.9-9.4 K Ohms)

While the last two resistances are slightly outside of the reference ranges, the first 3 look pretty good. Could a small change in resistance like this in the TPS cause such a rough idle? I sprayed the outside of my intake, TB and all the vacuum hoses around that area with TB cleaner and didn't notice any change in idle, which has me less suspicious of a vacuum leak. I hate to replace the TPS if its not the source (since it is a $100 part). I have to drive down to Oregon on Thursday and was wondering if I'm doing any harm to my truck by driving it around like this. Thanks for all your help so far guys!

kmat123

When I spray the junction between my TB and intake with TB cleaner the engine revs up, which leads me to believe there is a leak there. I installed a new gasket when I reinstalled the TB (which is paper thin), but just tightened down the bolts and didn't torque them to factory specs (14 ft/lb). I think I'll reinstall it and see if that fixes the problem.....does it sound like I'm on the right track here?

kmat123

Well I removed the TB, reseated the gasket and reinstalled the TB, torquing the bolts down to 14 ft. lbs.....fire it up and....same rough idle. I sprayed the junction between the TB and intake with TB cleaner again and the RPMS still jump up. Has anyone had issues with aftermarket TB gaskets creating a good seal? Would you guys recommend I get another gasket and double up, or go get a factory gasket? Thanks!

FOCUSHERE

try some RTV thats what i would do just like a thin coat let it dry then fire it up

Chico

kmat123

What is RTV?

84sr5yoty

Try a genuine Toyota gasket before using RTV. The gasket won't cost you more than a couple bucks, if that.