Memphis4X4

At birth, my '91 Runner was unfortunate enough to be dealt a handicap for life in the form of a 3.0L. Yes, I have helped it through all 12 and a half years to over come the cruel kidding of others of it being slow, by doing the ISR mod, frequent tune- ups, synthetic oils throughout, and a K&N filter (yeah, I bought it 10 years ago and now know better). But recently, the ol' Runner has been plagued by being even slower than usual. It acts like it starts out in 3rd gear. When the the rpm's get to 2.5-3k rpm, it then revs up to 4-5k. It's almost like its kicking down from 3rd to 2nd gear but my Transmission guy found that its shifting fine. When the weather outside is cooler and less humid, the truck doesn't act this way but seems to run normal and shift correctly. Running it with the ECT PWR button engaged seems to help it when it is running poorly but it doesn't cure the problem. My mechanic told me that it had tripped a TPS code '41' but when he looked at the TPS sensor, it appeared to be functioning normally. The mecahnic then said that it is acting like the catalytic converter was clogged. He even shot an IR/laser temp guage at it and it shot up to over 400 degrees in front of the CC. We pulled the CC off of the truck and it is perfect, you can see right through and there is nothing rattling around or clogging it. The exhaust has good volume running through it so he didn't think it was the muffler being clogged. So now I'm back to square one. Something is tripping the TPS code and making the truck underpowered but I can't determine what it is. I think I described everything. Any ideas on what it could be?

David

mtnfreak

Fuel filter.

Churnd

or your EGR valve might need cleaning.

AgRunner06

The TPS also needs to be adjusted correctly. It may be fine, but if it is misadjusted then there will be problems.

Here is a great page on the TPS. Down at the bottom of the page is the symptoms of a bad or misadjusted TPS. Just below that, it discusses the problems that a bad TPS can cause in the transmission.

Good Luck

Memphis4X4

That's what I love about this Forum. Quick responses that have merit!! Thanks mtnfreak and Churnd!!

The fuel filter makes sense. So does the EGR valve. I've changed the fuel filter a long time ago......what a beeoutch! I've never cleaned a EGR valve. Any suggestions?
What's involved? Isn't it located low on the passenger-side of the 3.0L....in a very hard to reach area?

Memphis4X4

Thanks AgRunner. I remember you were having TPS issues and I took print outs of this page with me to my mechanic the other day when he was checking my truck out. He beat me to the punch by telling me that the TPS is a pain to adjust and must be adjusted correctly. He check the adjustment and it appears to be fine. I asked him if the TPS sensor could be just going out and he said that they typically either work or they don't. So if mine is working then it would be an adjustment problem like you suggest. He checked the adjustment and it was fine.

Thanks again for a good suggestion.

David

Churnd

It's not that hard to reach, but I have no idea how to clean one. I just had my header gaskets replaced recently, and the mechanic who did it also cleaned my EGR valve. I noticed good bit more power afterwards and I'm getting over 300 miles to a tank of gas now rather than barely making 250 sometimes.

Memphis4X4

Wow!!! I'm barely getting 250 and it's dropping steadily. I'll check with my mechanic and tell him that I need the EGR valve cleaned and to replace the fuel filter. I'd love to get over 300 miles per tank.

Thanks for the input!

Firefyter-Emt

EGR is a bitch to get out.. You have to pull the intale plenum to allow the inside of the EGR to be pulled all the way out of the intake plenum. (It is like a foot long!) It goes almost up to the TB!

Memphis4X4

Thanks Lee. I thought that I had heard that it was hard to reach. I'm glad that my subliminal memory is working .

If it makes as big of a difference as Churd says, I'll have the guy that wrenches on my Runner work on it instead of me. It's just $$$$......

David