[ZaxXTerra]

Hi all,

2004 Xterra V6, Automatic 2WD, in Florida. Weather is 60 - 74, beautiful right now.

I just changed the a/c belt today (confidence builder, I'll tackle the others soon). Also decided to adjust my timing a bit. She's been pinging on mid-grade gas.

All went relatively smoothly, except tuning the TPS which I eventually got right.

Test drive time, and I have apparently created more issues than I solved.

Service Engine Soon light is on, steady (no code reader at the moment). Fine, I can put electrical tape over it.

Shifting from Park (warmed up, 600 rpm idle) into any gear but Neutral and the rpms jump to 1000 momentarily. It settles right back to 600 idle, but a bit unnerving. Meh, it will probably shake itself out, TPS bi-polar episode.

I'll take it easy. Barely on the gas, 1/10th throttle or less.

1st gear, smooth, strong, happy.

2nd gear engages, smooth, strong happy until 1400-1600 rpm. Then a mad downshift to 1st up to 2500k, then back to 2nd.

All good from there.

Slowing down, no problem, no other shifting issues.

Smooth decently strong running at all other speeds and throttle input (1/10 - 1/2). Heavier throttle just makes for a wilder ride.

I've torn down past my previous project, cleaned the throttle body, triple-checked all vacuum hoses and everything I've touched. Disconnected battery cable for 30 minutes.

Same problems. SES light, shift from park rpm jump, and the wild downshift at 2nd.

Before I grab the 12 gauge and put it out of it's misery, can someone point me towards a less costly repair or game plan?

:machinegunner:

 

[ZaxXTerra]

Update:

I finally bit the bullet and bought a code reader.

"P0122/ Throttle Pedal Position Sensor / Switch A Circuit Low"

I've cleared the code, shut down, restarted, same issue and warning light.

I'm pulling the TPS (again!) and cleaning all connections. I'll post any updates.

 

[ZaxXTerra]

Quick update - I've cleared the code, cleaned the TPS. Symptoms persist. New TPS on order from Rock Auto.

 

[ZaxXTerra]

Update: Brand new part received yesterday, couldn't get to it until this morning.

Installed, connected, fiddled with, symptoms persist.

Both battery cables are currently disconnected. I remember seeing that 30 minutes of that will clear the computer, hopefully it will reset and re-learn.

If not, it will be going to a mechanic.

I loathe these stupid sensors and computers...

 

[Cody Hurlock]

Did you ever figure out this problem? I have the same issue despite replacing my TPS and adjusting to normal idle speed.

 

[kms1990]

you need to do the relearn for your idle after messing with all that stuff follow these instructions and you should have steady idle and shifting: https://www.nissanhelp.com/diy/xter..._nissan_xterra_idle_air_volume_adjustment.php

 

[Cody Hurlock]

You sure? I thought we are not supposed to touch that idle adjustment screw? I feel like my issue is somewhere with the throttle. The tab at the bottom of the fast idle cam thing is bent. The TPS only works kind of properly if I turn it all the way to one side, there's no room for adjusting the TPS. I also have a really rich fuel smell in the exhaust. Perhaps I should start a new thread. lol. I just feel like this might be linked to this thread.

 

[kms1990]

You sure? I thought we are not supposed to touch that idle adjustment screw? I feel like my issue is somewhere with the throttle. The tab at the bottom of the fast idle cam thing is bent. The TPS only works kind of properly if I turn it all the way to one side, there's no room for adjusting the TPS. I also have a really rich fuel smell in the exhaust. Perhaps I should start a new thread. lol. I just feel like this might be linked to this thread.

you can, just have to doi the procedure correctly. its a good place to start as idle and air volume being off will throw everything out of whack