Well, the verdict is in ... Both the MAF sensor and the TPS had to be replaced. Apparently when I cleaned the MAF sensor the last two times it must have damaged the IAT sensor on the assembly. It was reading the Intake Air Temp wrong by quite a few degrees. It was reading way hotter than the actual air temp that was going through the intake. To top it off, the TPS not only had a dead spot and mis-reads as the percentage of TSP increased, but it also was sticking. So when the throttle was released it would not respond quick enough to the changes in throttle position. You could tell by moving the new TPS by hand before installing it and the movement was really smooth and took little effort, it also returned to stop quickly. But the one I removed from my throttle body was stiff to move and when you released it the sensor did not return to stop no way near as quick as the new one did.

All I can say is, after changing both the TPS and MAF sensor and running it down the highway, in only 10-15 minutes as the computer readjusted I can tell an immediate difference and the acceleration is back now just like when I first installed the SC. Just goes to show you how critical these two sensors are for the proper operation of the computer to control the flow of fuel and engine performance. So now after about four days since the sensors were changed out my rig is running great now.

Another thing to point out is to make sure when cleaning the MAF sensor be extremely careful on how you clean it and what you use to clean it with. I was using a carb cleaner that indicated it was sensor safe, but maybe my cleaning method was a bit too agressive and I damaged the IAT on the MAF. The TPS was just normal wear and tear. According to one of the parts guys at the stealer, they have replaced quite a few of the TPS sensors. Total monetary damage: TPS around $54.00, but the MAF was around $145.00 which initially sounds like a lot, but to have the engine running properly again (well, not like Gadget's, yet) is a pleasant change from what I was dealing with the last few months. I will defintely be more careful during my future intake cleaning routines. <img src="/forums/images/graemlins/shame.gif" alt="" />

Ricochet

This sounds exactly like what my car is doing. Do you have the p/n for the TPS sensor? My diag stuff for the 4runner shouldn't be here until tomorrow (i have a generic scan tool but no codes) so I can't look at IATs but I can go ahead and replace the suspect TPS.

Thanks for the help and posting your fix.

The TPS part number is 89452-35020. The part number for the MAF (Air Flow Meter) is 22204-07010. Good luck getting your running right again. I hope this helps out.

Ricochet

Thanks for the feed back.. <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />

This is an excellent example of how we all learn something from each other's experiences...

Thanks, after talking to the dealer where the truck was bought about parts - I realized they weren't coming off list on parts (this is Beaman in Nashville). I called another dealer in Nashville (John Roberts) and they agreed to sell me the parts at wholesale. Had to order the TPS -- it will be here Sat morning.

Ricochet - thanks for all your help -- I think the p/ns made it easier to convince them to sell me the parts at wholesale.

D.

Ah--didn't look at the year <img src="/forums/images/graemlins/shiner.gif" alt="" /> Nice little writeup there tho'. Someday.....newer Toy.... <img src="/forums/images/graemlins/kewl.gif" alt="" />

You didn't already know to avoid Beaman's Parts Depts???

ALL Beaman Dealers stick it to ya every way they can...

(I grew up in Hendersonville, that's how I'm familiar with them) <img src="/forums/images/graemlins/cheers.gif" alt="" />

Yeah, that will be the last time I ever talk to Beaman.

As far as the fix goes, i replaced the TPS - no real improvement at all. I then replaced the MAF and reset the ecu. It seems much improved but not gone:/ Any other ideas?

The plugs looked great but I'm going to go ahead and replace them anyway. After that -- I'm not sure where to go next? Air/Fuel sensor? o2? anybody have any ideas?

How long have you driven it since you replaced both the TPS and the MAF? I did not notice a full recovery until about 1-2 days worth of driving. I did notice an immediate difference as I mentioned before but it did take a couple days driving for the computer to re-learn and things to smooth back out.

On your old TPS, did you manually operate it (using a screwdriver or something like that) to see if the TPS movement was sort of stiff and if the TPS sticked a bit when you released it? Also did you check the readings with a ohm meter to see if you have actul dead spots in the potentiometer as mine did? Just curios. I believe my MAF was the biggest contributor with the IAT reading being off. It is possible that other sensors such as the O2, etc may be affecting it somewhat. If you have not been driving it at least a couple of days, give it just a bit more time before digging into the other systems. Like I said, mine is running great now, but that is not to say that yours has doesn't have some additional issues to deal with. I think I remember you mentioning you are getting an OBD-II tester? If so, run some tests when you get that and post up what you find on the IAT, TPS at idle and WOT, and the Long-Term fuel trim. SO as not to drag this reply into a book, you need to next look at your fuel trim values as they can tell you a lot of how the computer is being told to deliver fuel to the engine. Post up what you find if you do indeed get an OBD-II tester.

Everyone is here to help out if they can. ANd I defintely do not want to steer you in the wrong direction. My fixes did correct my rigs problems but as I said previously that yours may have some similarities but also have something else to it.

Ricochet

definite improvement but only drove it for 20mins or so. I'll try to drive it some this week to see if it smooths out:)