I wish our injectors were cheaper.. 135$ x 6 for oem injectors is pretty expensive for a guess. I might try to find a shop that tests the spray pattern and cleans them

Do you have any exhaust leaks?


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I did notice a very small pin hole leak in the muffler the other day. But that being quite a ways behind all the 02 sensors would that cause an issue? I was just planning on throwing some weld over it.

Yes. That's why I suggested the fuel filter and rail pressure. This verify your fuel pump is working properly. Eliminating that as a possible cause.

Fuel injector cleaner is fairly cheap and a few tanks of gas should have your injectors clean if they are starting to clog slightly.

Our torque converter lock at highway speeds. Basically all vehicles have locking TC after 1982. That can be tested via the FSM. I doubt that's the issue though.

Also when was the last time the atm fluid was exchanged and the pan magnets cleaned with a filter change.

Atm fluid gets full of contaminants and thus stops lubricating and turns until almost sandblasting material with all the metal microscopic particles etc.

So with 300k on the tranny, I would at least check the fluid and see what it looks like.

Low atm fluid can cause issues too. Which I saw another user say about a shifting solenoid. Very possible dirty fluid and sticking valves in the atm causing it.


Lots of possibilities that you going to have to use process of elimination to solve the issue.


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I did a transmission fluid change and filter when i did the JDM swap 5ish years ago. Since then i have just changed fluid out. But i will change out the fluid again and probably drop the pan and look things over regardless. Thanks for the ideas guys! i just need a list of probable causes to look at.
Any idea how to check the torque converter?

Reversion will suck fresh air in the exhaust stream. Screwing up the O2 sensor readings.

Put the MAF PID and the LTFT for bank 1 sensor 1 in your ScanGauge.

When it dogs down what is your percent load?

If you turn on your ignition and watch your TPS position without starting it does the position increment smoothly when you slowly depress the throttle to the floor?

How much tension is on the TV cable going down to the transmission? Too much is not good. At idle position you should have a slight amount of slack.

I think I found the real time Air Fuel Ratio for the 96-98 automatic ECU but need some to test and verify it. I feel it’s real time and behaves as I’d expect it to. You could try that too and watch what it’s at when you loose power.

First thing I’d look at is the TPS. If you got 300k miles on it......at highway speeds it could be reporting a lower or higher position than actual causing the ECU to chose the incorrect fuel map and spark table.


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At 50mph I had 19% throttle and around 48% load on as flat of a road as I could find. 55mph was not much different. Say 19 to 21 for TPS and 48 to 51 for load.


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At 300k miles on this trans and 5 years since a drain and fill; I would definitely drop the pan, change the filter, then do a complete fluid change (flush). Timmy has a good video on it using a pump. I found a $17 Walmart pump to work just fine.
YouTube

I do the trans flush on every used vehicle I buy. Hardly anyone changes the brake, power steering, diff, or trans fluids like they should.

I was going to suggest checking the transmission kick down cable as well.

Dont those occasionally bind and cause issues too.

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The Factory Service Manual [FSM] has a testing procedure in it.

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Did you say your running mud tires? 33s? Have you switched tires? Maybe heavier wheels and tire combo??

Yes I’m on 33s but it did this when I was on 31s as well. Has been an issue for awhile now


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Sorry just getting back. Been changing out knock sensors and wiring harness to fix a po330 code I’ve been having. (Ended up being a short in the harness). Also did valve cover gaskets and all the seals while I had it apart. Changed out pcv valve as well. Got it all back together now so I tried tour test with my scan gauge.

I’m reading the same as you are at 50mph and 55mph. 19-21 TPS and the LOD varies between 42-50.

I tried a test at 70 as well. TPS @ 30 and LOD at 64ish. Other than an initial spike when my torque converter unlocked (RPMS jump from 2200 to 2600) I got the about the same readings when at 2200 (locker torque converter) and at 2600RPM (unlocked torque converter) once it leveled out.


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With ignition on and engine off my THrottle position sensor is at 12 without my foot on the gas (idle), goes up smoothly from there as I slowly depress the throttle and maxes out at 75 TPS at full throttle. Is that normal?


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