p0120 running rough

Great to be a part of the forum. Bought my first tacoma in January, 97 Tacoma 2.7 5-speed 4x4. Have replaced all spark plugs and wires, both O2 sensors (code cleared after doing so), cleaned the MAF and throttle body. Replaced TPS because of the P0120. I cleared the code and it immediately came back in. Went for a drive and at 30-40 mph the truck started jolting and seemed to have a hard time getting fuel because I had intermittent power. Not sure where to go from here. I've read through a hand full of forums here and most say throttle body being dirty can cause this so that was my last ditch effort before posting. Any advice would be great.

 

Not sure about your tps but older toyota I worked on, the tps have to be adjust/clocked on properly. they're not a direct screw on, no adjustment needed type tps. Just not sure about your tacoma.

If you have live data reading on your scanner, you can also check this out if it's seeing correct voltage:
A scan tool connected to the diagnostic link inside the vehicle will tell you if the ECM is reading the signals from the TPS. The voltage should be under 1 volt at idle and about 5 volts at WOT (Wide Open Throttle)

 

Thanks for the reply. Is adjusting the TPS a dealership requirement? I don't have live data, just a scan gauge. Also, I've read people checking voltage on TPS without the vehicle running but couldn't quite grasp how to do so. I'm hoping that fixing this will make the truck run smooth again.

 

Where did you get your TPS? A part like that should only be bought OEM.

Source: rebuilt the S52 in my E30. When I dropped it in it would run like crap no matter what I did. Scan tool said the CPS was bad but since I installed a new one I just wouldn't believe it. To much time and money later I found out the sensor I got from Amazon was DOA.

Does it idle okay when cold? If it runs okay on the cold loop that is a place to start.

 

Advanced auto. It does idle on first start cold okay. I'm not a genius at specs but it's about 1100 RPM. Once it's warm in between 680-740 at idle but will still idle okay. Only has an issue really under acceleration. After it ran rough yesterday, a couple minutes later I had no issues and perfect acceleration. The issue seems to come and go

 

Your TPS could be spotty. It's an easy part to swap in and out, I'd pick up another one and see if it does the same thing. If so, return one of them. Just be careful and keep the part clean. If you're scanner is telling you that it's still the TPS, start there.

 

Can you advise based off 02Hilux with it maybe needing to be adjusted? Also this is the second one I've purchased. First one was off Amazon and they accepted the return. That one cleared the code for 3 weeks, ran great and then the code came back. This new one from advanced never cleared the code

 

Unfortunately I can't. I'm basing my knowledge of a Toyota TPS off of a 2002 with a V6. Mine does not require any adjustment

 

On older pickup, non tacoma, once you remove the tps, there's two tab that is protruding from the tb that is attached to the tps. Behind the two tab is what look like a coil spring. The tab have to be slightly move into positron before installing the tps. If not, voltage reading will be off. Just not sure about 3rz tacoma.

Only thing I find online is that 95.5 to 97 3rz require adjustment and 98+ are not adjustable.

I would help verify but I no longer have my alldata vehicle repair software. Maybe someone can chime in?

I'm sure there's a certified toyota mechanic in TW with fsm that is willing to help

 

the intermittant nature leads me to believe that there is a connection issue between the pins on the TPS and the ECU... the "wiggle" test is the place to start.

 

Wiggle test worked. For now I think. I do have scan guage 2 and tps reads 11. I think I found that the wiring is bad. I can wiggle and the engine wants to cut out but when I don't wiggle it idles great. Haven't looked for wiring harness or anything yet. Weird I threw an O2 sensor code while moving the wires and then it went away. Just replaced those a week ago with Denso