Fuel injector ECM terminals

[ectech]

Since the black on those plugs goes up the threads, that hints at an oil issue, not a running rich issue (though maybe it still is just running rich). The correct Denso plugs work just as well as the correct NGK plugs. Most 5vz's came from the factory with 3 of each...

What year is the truck? Since you talked about the wrong ECU pinout, I'm assuming you have a '96-'98.

Interesting to see such bad short term trims - but I guess the long term trims just haven't had a chance to adjust yet since it hasn't spent much time in close loop.

It is easy to miss the air assist hose, so maybe that's where your air leak is coming from (if that is the issue!). I suppose it could also be a bad O2 sensor always reading lean, so the engine over-fuels? Stuck injector(s)?

-Charlie

It's a 98.

I did a smoke test yesterday and I have smoke coming from the iac valve and slightly out of the PCv grommet.
It's not coming from where the iac valve meets the throttle body but from where the plastic piece with the plug meets the body of the iac valve.
Not sure if it's related but if I have the vehicle over 1300rpms either by using the pedal or adjusting my throttle cable to increase the idle, the misfire seems non existent and I don't have a flashing cel at higher rpm. I am going to run some test on the iac valve that I found from Timmy the tool man and if everything checks out, see about resealing where the smoke was coming from to rule that out. I'm not sure if the iac is as sensitive as the MAF sensor but I did take the iac valve off and clean it when I was doing all the original work.

I've confirmed it's not the injectors through swapping them around and also having the ones I have on sent off and cleaned and tested.

What's the best way to test the O2 sensor? Can I tell from the readings on my obd data?

I've confirmed all the vacuum lines are plugged in multiple times and I'm sure of that. However, even though I labeled everything, I have questioned if I accidentally hooked a hose up wrong. I feel like they only way I can confirm this is by having someone with the same vehicle come by to compare. I haven't found any diagrams that have been very helpful.

I appreciate your input

 

[phattyduck]

What's the best way to test the O2 sensor? Can I tell from the readings on my obd data?

I've confirmed all the vacuum lines are plugged in multiple times and I'm sure of that. However, even though I labeled everything, I have questioned if I accidentally hooked a hose up wrong. I feel like they only way I can confirm this is by having someone with the same vehicle come by to compare. I haven't found any diagrams that have been very helpful.

I appreciate your input

And OBD-II reader that does live data should be able to read the ECU's version of the O2 reading for the main and sub O2 sensors. That will be a start. You may still need to break out the multimeter to be 100% sure.

The sticker on the hood should cover *most* of the vacuum lines, though not all...

-Charlie

 

[Robb235]

IWhat's the best way to test the O2 sensor? Can I tell from the readings on my obd data?

And OBD-II reader that does live data should be able to read the ECU's version of the O2 reading for the main and sub O2 sensors. That will be a start. You may still need to break out the multimeter to be 100% sure

If the upstream sensor hasn’t been replaced in a long time, or if you don’t know the last time it was replaced, I would just put a new one in as part of preventative maintenance. Denso p/n 234-4162 (or 234-4161 if manual transmission, different length wiring harness on the sensor).

 

[ectech]

If the upstream sensor hasn’t been replaced in a long time, or if you don’t know the last time it was replaced, I would just put a new one in as part of preventative maintenance. Denso p/n 234-4162 (or 234-4161 if manual transmission, different length wiring harness on the sensor).

I'm going to give this a go when I get back to it, since it's past due anyway. I've been told that wouldn't cause it by more than one person but also the one thing I haven't tried. I'm not coming across any record of testing the O2 sensor and don't recall if I did either. Now, being able to get my fuel trims and doing some research I'm learning the O2 sensor could cause the exact issues I'm having but seems I should be getting codes for more cylinders. I didn't check my pending codes to see if maybe there were other cylinders pending.
Appreciate your input.