Live data p0172 p0175

[Ksat]

I've never done the test on my Lib, but usually you're looking for a pulsing ground on one of those wires when the engine is running. That would be the control signal coming from the PCM commanding the coil to turn on/off. By the way, it would be a good idea to unplug the injector plug on the same cylinder when you're doing this, as you don't want unburned fuel in the cylinder (or in the cat).

 

[Jhkj04]

Seams odd to have no positive on pin 1-3 of the coil plug and on iac ground and faint ground never pos. At this point I feel I could have required the entire pcm/ecm and all these sensors. LOL I’ve had another project sucking time and I’m back to the Liberty.

 

[Jhkj04]

P0068 came up. Did some testing on the intake sensors. Throttle position sensor affects the running when up plugged, map and the iac do the same. The air temp does not so I tested it and watch the scan tool. It’s temp while retesting on the scan tool does not change the fuel trim. Temp
Was 90 with a heat gun 215 and no change in fuel trim or running. Unplugged it goes to -20 no change. I’ve also ordered a new ecm. $170 vin programmed.

 

[CRD-Joe]

For what it's worth I had issues in my gasser back in the day. Turned out my new fuel injectors I put in were defective. I purchased a refurbished set and my fuel trims went back to normal. Unfortunately we sometimes get bad parts. I too chased everything else down, before deciding to rebuy the injectors, but used refurbished OEM ones. That's what solved my problem.

 

[Jhkj04]

That’s not a bad idea. I did get generic injectors. I’m now passed the cancel timeline on the ecm so gonna try it when it arrives in 4/5 days plus I’m rebuying the intake temp sensor only a mopar unit and the map as a mopar. I’m feeling the ecm should do something when the air temp sensor changes.

 

[Ksat]

You want the ASD relay to be plugged in when you test at the coil's connector plug. The ASD is there to provide +12V (when conditions are met) to all 6 coils, so plug it in and see if power is making it to one of the pins there. I would imagine the ignition should be in "on" position as opposed to having the engine running when testing, as you might not measure the proper value (or have your test light illuminate fully) because, in the latter scenario, the coil is continuously being pulled to ground. The second wire on the coil plug should be your pulsing ground trigger from PCM (when engine is running).

The service manual doesn't appear to go into what the third wire is, but typically that's (steady) ground, which is utilized by the coil's embedded transistor.

Let us know what you come up with. I have a similar looking "logic probe" to the one you showed and I could try it out on my '06 to see what I get. The wiring on your '04 should be the same.

 

[Jhkj04]

With the asd relay in and starting the coil plug 1/3 pin left and right are zero nothing the middle jumps around on volts.when just the key is on asd in 1/3 are dead the middle is ground until cranking.

 

[Ksat]

Okay. I'll make a point to check the wires on my kj this week and let u know what I come up with.

 

[Jhkj04]

Thanks, I swapped the map to a mopar unit. Fuel trim seams closer at -8 to -17 at idle. Ecm still on the way.

 

[Jhkj04]

New info, so my code reader I felt only had fuel trim for short and long on bank 1/2. Under the 02 sensors it shows a short term fuel for each 02 and both banks rear sensors show 99% and does not move for fuel trim the 02 shows slow moving 780-860v but not allot of movement. Bank 1 sensor 1 02 shows v .780 to .035 short fuel trim the highest of .08 mostly all negative. Bank 2 sensor 1 shows about the same activity.

 

[Jhkj04]

New ecm came today. Big disappointment. Was not the issue same codes same fuel trim. What’s scrap metal bring per pound these days?

 

[DadOSix]

New ecm came today. Big disappointment. Was not the issue same codes same fuel trim. What’s scrap metal bring per pound these days?

Really silly wild guess - but - are you or have you run e85 fuel in your jeep?

i ask because I saw a vid on YT from South Main Auto on a truck that had P0172 and P0175 codes and wild fuel trims.

The ECU on that job had decided that the alcohol content of the fuel was about 36% rather than less than 10 or 15.

They recalibrated the ECU and alll was well. I dont know how it applies to KJ's but found the info interesting.

 

[Jhkj04]

Not a terrible guess, I have been running 90-91 to clean out the tank and lines so not sure I have any e85 in it.

 

[DadOSix]

It’s a 3.7. New- injectors, head gaskets, timing chains etc, iac/mopar , Mass air and map not mopar, 02- Ngk, plus Ngk/ntk, coils mopar, pcv, coolant temp sensor, cam sensors, intake gaskets, valve cover gaskets, fuel rail new o rings, took out cruise and blocked the vacuum line. Before it was running on 5 cylinders as one had a stuck open intake valve with a thrown rocker pass side number 6 and a bad gasket and coolant leak into the exhaust on driver number 5.

new - injectors - were these oem or generic? i’ve been sifting some yt about 172 175 codes.

some education on fuel trims here - https://youtube.com/playlist?list=PLq_Q0mT6-rcd8KtjDICHa0itIm4kwBa8C

Mike is a genius on these.

also - my SMA Eric O had a gm product that they threw the whole parts store at to find the owner had multiple issues, but non oem - generic injectors were the cause

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[Jhkj04]

Well that’s my life in video. Hate it but I’ll swap injectors again back to stock. I think my factories had a couple broken ones can I run remanufactured mopar or Bosch units?

 

[DadOSix]

Well that’s my life in video. Hate it but I’ll swap injectors again back to stock. I think my factories had a couple broken ones can I run remanufactured mopar or Bosch units?

if you have a parts yard nearby, you might want to see if any 3.7 are there. I got 4 ’self pulled’ injectors from the only 3.7 on the lot. I hook them up to a 9v battery and spray carb cleaner thru the inlet til i get a good pattern.

not saying this is the best way for you, but i am a cheap b*stard at heart and will try ’things’ to make it work. My 06 was quite happy with 2 refitted injectors.

i ‘ think ‘ the oem are bosch - should be no trouble either way.

take notice that he replaced the new generic MAP / MAF / etc back to oem stock items, even though they were used. Unfortunately, today, new does not mean good. I am redoing brake calipers on my 2014 T&C van, as a new reman blew the dust boots right off on our maiden voyage. quality— - - where is it anymore?

 

[Jhkj04]

All helpful guys, on the journey I swapped the map and air temp/maf back to mopar the iac new mopar the tps new mopar I’m down really to injectors being new but generic. With is being both bank 1 and 2 it doesn’t sound far fetched just a bumper.

 

[DadOSix]

All helpful guys, on the journey I swapped the map and air temp/maf back to mopar the iac new mopar the tps new mopar I’m down really to injectors being new but generic. With is being both bank 1 and 2 it doesn’t sound far fetched just a bumper.

Appreciate the update! We just want to see you get this solved!

 

[Jhkj04]

Same, been a project. Should have started with the motor and not the lift but knew I wanted it all done for this year. Trying to go to Colorado in June. Just ordered these I’ve been away from the garage so couldn’t look at part numbers.

 

[DadOSix]

Same, been a project. Should have started with the motor and not the lift but knew I wanted it all done for this year. Trying to go to Colorado in June. Just ordered these I’ve been away from the garage so couldn’t look at part numbers.

should work just fine. the set i lifted from the donor engine was out of a dakota.