AK to HI engine code every new part gets worse

[Ecomike]

Well you earlier reported 135 for #1, now it is 145?

Since #2 is 160, 135 is too low and 145 is OK. 160-145=15 which is OK and 160-135=25 which is too high


Question is why was it 135 earlier on #1?

Otherwise that looks OK.

 

[SBpunk]

Sorry I posted it up without the paper in my hand early in the morning. Its 145 on number 1. 0400 is my wake up time for work so Im about half dead and need to stay off the forums until 1200+ lol

 

[Ecomike]

Have you used a noid light yet to see if #1 flashes the noid light?

If the noid light does not flash with the new harness, it is likely a burned out injector firing circuit in the PCM board.
The old, bad wiring harness may have damaged the PCM

Or if it flashes, then maybe you have the spring issue others had. Spring swap is pretty easy!!!

 

[SBpunk]

I havent hooked up the NOID since the new harness has been in but I'll go do that here in a second. Seems like all signs are pointing toward the PCM but I want to save that for the last resort. Its hit or miss getting a new one in. Guy on eBay is selling them pretty decent priced and a lifetime warranty. Rather spend money on a 7$ part first though.

 

[SBpunk]

Trying to find a good write up for the valve spring swap but nadda so far. Ill see if Checkers has some springs and try to do it this weekend

 

[Ecomike]

Don't forget the old posts I made below on changing the springs. Link to the spring compressor tool, $17 and link to the you tube video. 5/16-3/8" nylon poly rope shoved in through the spark plug hole, fill it up, then turn the crank on the bolt on the crankshaft-harmonic balancer to take the piston to TDC, and the rope keeps the valves from dropping into the engine, while you swap the springs, one cylinder at a time.

 

[SBpunk]

I got a spring compressor the other day when you sent it just incase I needed it. Hopefully I'll be able to knock it out this weekend. I'll let you know how it goes

 

[SBpunk]

Just an update. Went around this stupid island all day and no one has the springs here. NAPA didnt even have a part number for it. So I ordered from WeRMopar. Should be here in a few days hopefully. Got 12 springs 6 intake / exhaust seals

 

[Ecomike]

A short magnetic tip grabber is real handy too. See the video.

 

[SBpunk]

Ok so its been awhile since I've updated due to some other projects that came up. I just got my XJ back today and swapped out the PCM. Its now throwing an instant P0743 code. What bothers me is everything I've read the code usually takes awhile to come back. I'm ready to throw a grenade in this thing and push it off a cliff. Its either that or take it to the dealership. Kind of lost in what direction to go now.

 

[Ecomike]

http://engine-codes.com/p0743_jeep.html

LOL, the grenade and cliff might be cheaper.

Sell it? LOL

Don't give up just yet. Someone with a full blown scanner system, like the Snap on one that can test things step by step may be the way to go, since it still sounds like bad wiring (harness) stuff somewhere.

I take it still had issues, so you swapped the PCM?

But is the PCM a known good swap? It is saying that there is either an open wire or short on solenoid #3 in the AW4, or the wiring from the solenoid to the PCM, or a bad ground. Solenoid #3 locks up the torque converter.

 

[Ecomike]

Pull the PCM back out first and make sure a pin did not get bent during assembly to the bulk wire connector.

Not sure what year, but I read recently about one OEM case or mounting screw being too long on one of the late model years that screws up the PCM data. Screw just needs to be shorter.

Does the engine run better with this PCM? Or not?

 

[Ecomike]

Also, does this jeep have an alarm system, aftermarket, or custom electrical gadgets that might be dorking with the wiring?????

 

[SBpunk]

Its pretty much the same Mike. Only difference I can see is that if I pull the number 1 injector connection off it actually changes the engine. Its still shaking and bogging down though. The PCM came from an online shop with a lifetime warranty. I'm going to swap them back and see if I still get the P0743 code. If I do then I know its not the PCM. I shouldve hooked up my scanner before I swapped it.

It has the overhead console so I'm assuming stock it came with an alarm / keyless. Could the alternator surging do this? Screw with the wiring I mean? Im not really sure how it would but if someone told me my exhaust was two inches to long I would be out there with a grinder if I thought it would work. Anyway I'll take apart the PCM and see if I bent anything.

 

[Ecomike]

I thought my NSS was bad for a long time, years, had no back up lights, finally replaced the NSS when I replaced the transmission and noticed a bent pin in the NSS bulk harness side connector near the dip stick, when I was connecting it all back up, LOL.

So why the question about the alternator?

If the PCM is making a difference, how much is the difference? Could the #1 injector wire be partially shorted in the harness somewhere, and finally damaged the original PCM, and the new PCM is trying to run it but having a problem with a partial short?
The best dealers do have high tech diagnostic electronics systems that might help find a bad wire faster, but finding such a dealer is another story. I hate stealerships....

 

[SBpunk]

The harness has been swapped out for an entire new working one. I still havent got to swap the PCM's back over see if it makes any difference. The reason I asked about the alternator is I swapped to a 136a alternator (upgraded the wires). I was having problems before the swap but not sure if its been causing more issues.

I'm going to run out and see if I can swap these PCM's to see what code I get. Hopefully its the same and I dont have a bunk PCM. I really dont want to take it down but im running out of ideas. The dealership will charge me for the 80 things I've already done before they figure out what the problem is.

 

[Ecomike]

The dealership will charge me for the 80 things I've already done before they figure out what the problem is.

That is true!

You did the valve springs and seals already too?

If the old PCM does not throw the code, it does not mean the new PCM is bad!!!

Been a while and multiple threads, forgot about the W-harness swap.

This is a tough one!!!!

 

[Ecomike]

You might want to verify the serial number on the new PCM and make sure they gave you the right one!!!! Ask a dealership parts guy, give him your VIN # and the PCM number.

Alternator topic, I not the expert here on them, but the later years, yours included have the voltage regulator in the PCM and not the alternator if that helps.

But nothing you posted before gave any indication of a problem in that direction that I recall.

 

[SBpunk]

Ok swapped the old PCM in and cant get a code but the engine is still weak and shaking. Only put in 1 screw to see if it was a grounding thing and nadda. I did notice something when I looked under. My passenger side UCA seems to have flexed into my fuel lines and oil pan. The fuel line that goes into the rail is almost kinked off. I'm not sure if fuel issues could cause a code but its something I hadnt noticed before. Any thoughts on that?

 

[Ecomike]

Don't know, I doubt it, but I fix any fuel line issue first, and test fuel pressure before and after, at idle and at say 3000 rpm (during the TPS sweep from one to the other).

The is another computer, the TCU that talks to the PCM and the AW4 that I think should be telling the PCM if there is a solenoid problem or not. Might try the new PCM again, but pull the battery connection for a while to clear the TCU memory (and the PCM memory) after the install!!!!

Have you cleaned and refreshed the 2 bulk wiring connectors to the AW4 NSS and transmission solenoids, they are near the oil dip stick!!