Help with intermittent stall and P0120

[INDwinak]

For the last month, my 3rd gen (1997, Automatic, 2WD, ~100k miles) has had a very intermittent power loss, stutter, and stall issue when stepping on the gas (in drive) from full stop.

Last night it threw the first CEL: code P0120.

So far I've cleaned the MAF sensor, but trying to figure out what's next. Issue is so intermittent that I haven't had success in bringing it into the mechanic.

Any thoughts on what else I can do to diagnose or fix this issue?

Detailed summary of issue:
-Vehicle sometimes stutters or sputters when going from full stop to go, at red lights, stop signs, etc.
-Stutter or sputter feels likes engine stops or pauses for a moment (~1 second) then it recovers or it stalls.
-If it stalls, no CEL is thrown and I have been able restart immediately, so far, and keep driving.
-It has stalled 4-5 times.
-No stutter, sputter, or power issues once it is moving.
-On cold start, RPMs at idle can surge up and down a bit until they settle.
-Last night CEL came on, OBD II reads P0120.

Actions taken so far:
-Cleaned MAF

I haven't stalled since cleaning the MAF (72 hours ago), but it has sputtered a couple of times.

Next steps?
Was going to clean throttle body next and change fuel filter next.

Your thoughts, experience, and expertise are appreciated!

 

[spartacus]

For the last month, my 3rd gen (1997, Automatic, 2WD, ~100k miles) has had a very intermittent power loss, stutter, and stall issue when stepping on the gas (in drive) from full stop.

Last night it threw the first CEL: code P0120.

So far I've cleaned the MAF sensor, but trying to figure out what's next. Issue is so intermittent that I haven't had success in bringing it into the mechanic.

Any thoughts on what else I can do to diagnose or fix this issue?

Detailed summary of issue:
-Vehicle sometimes stutters or sputters when going from full stop to go, at red lights, stop signs, etc.
-Stutter or sputter feels likes engine stops or pauses for a moment (~1 second) then it recovers or it stalls.
-If it stalls, no CEL is thrown and I have been able restart immediately, so far, and keep driving.
-It has stalled 4-5 times.
-No stutter, sputter, or power issues once it is moving.
-On cold start, RPMs at idle can surge up and down a bit until they settle.
-Last night CEL came on, OBD II reads P0120.

Actions taken so far:
-Cleaned MAF

I haven't stalled since cleaning the MAF (72 hours ago), but it has sputtered a couple of times.

Next steps?
Was going to clean throttle body next and change fuel filter next.

Your thoughts, experience, and expertise are appreciated!

p0120 is the tps sensor code. Test the tps but there are instances when it's within specs and not functioning properly. Here is a fsm for testing.

 

[spartacus]

Cleaning the throttle body will help but sometimes leads to high idle for a while.

cleaned throttle body and holy c**p!!

 

[Malcolm99]

^That is for the 4 pin TPS 2001-02 and TB test procedure, here is the test procedure for the 96-00 3 pin TPS, if you take apart the TB, remove the IAC and clean it properly you shouldn't have high idle after cleaning the TB doing it this way, you will probably want IAC gasket Fel-Pro #61087. My TPS tested fine but had drop outs of signal from 10%-20%, the TPS should range from 10%-75% on live stream OBDII or scangauge.

 

[spartacus]

These part # are for 2000 sr5 so when orderin check against your Vin to be sure.
Throttle body gasket 22271-62040
Tps sensor 89452-35020

 

[19963.4lsr5]

Replace your TPS.

In my experience with this code by the time get the 120 code you already had signs of it going bad.

With a scanner reading live data and key on engine off the tps position should start at 10-11% and increase linearly to around 75%.


Sent from my iPhone using Tapatalk

 

[INDwinak]

Thanks all.

I'm going to order parts. Just to confirm, I am going to:

(1) Take off throttle body and clean it and the IAC valve.
(2) Replace my TPS.
(3) And since I'm there I'll do my PCV valve too.

Here's what I'm ordering, please let me know if I missed something or got something wrong.

Throttle Body Gasket (#2227162040)
IAC Valve Gasket (#2221562180)
TP Sensor (#8945235020)
PCV valve (#1220462010) , hose (#1226162041), and grommet (#9048018001)
JIS screw driver for IAC screws
Throttle body cleaner

 

[Malcolm99]

I didn't go over your part#'s, but if you're going OEM, the dealer with your VIN is best incase something is ordered incorrectly, (cross ref to what you've dug up) and that way you can just return it and ask for the correct part, but I would put off the PCV grommet for when you do the VC gaskets, it's has a tendency to crumble even if you warm it up and parts of it fall into the VC baffle and valve train and then you get to do VC gaskets anyways.