Are you able to repair the computers? We still have the old one but I'm not 100% convinced our reman is not the cause of the fan and high idle issues. I bought it from Flagship one and then read a bunch of reviews that was probably not a good move and not convinced it isn't the cause of the new issues.

I watched the live data and my ECT was going up as the engine was idling and giving realistic numbers so the CTS seems to be working fine. I also swapped around the starter and fan relays but the fan kept running so the new ECU is telling it to stay on for some reason. Soon as the key goes to run position fan is full blast.

The truck is not drivable right now but we've started and let it run for several minutes 4-5 times now and the idle is not coming down at all. I'm hoping once we can drive it around it will relearn.

 

I never have but I've re capped the VIC's and ohc computers with some success. Just got a VIC with 2 shorted caps. Replacing the 63v 100 uF cap thats first from the power pins with a 160v 100 uf cap. The 220 uF 63v Im replacing with a 100v cap. Other caps I have will go in too. Should bring'r back around. When boards get RMA'd in the PC world, they simply replace whats needed to get it functioning. Well a full re-capping is usually in order. Because caps get weak if others were shorted. I would pull the dead PCM apart and re flow the main connector solder joints. Then use the meter in horseshoe mode and probe both legs of each cap. They should have some resistance. 0.000 ohms means shorted cap. You can cross check by going into continuity mode. Caps that are shorted will beep. It is a silicone soaked board so torching the aluminum case to get it out is required. After repair I'd find some thermal conductive silicone and seal'r back up. Heres some guidance on it.

EDIT : When caps are shorted they allow unlimited power through. Like a trim pot failing to all the way open. So it could be just a cap. Or not. Worth checking. Lead free solder was used on these boards which cracks. Use leaded solder or silver mixed solder to ensure it doesnt happen again. If a cap is shorted the new caps uF rating must match but the voltage rating can be higher. The higher the voltage than what was there, the more durable the cap will be in that situation. So upgrading voltage on caps will make it last longer. I recommend Nichicon (audio grade caps that should be in there) or Panasonic caps. Both Japanese OEM as these boards were mostly made by Motorola. If there are a few caps for sale of the same voltage and uF rating that are different sizes measure the one you have and get a matching one as wider shorter radial caps are lower impedance than taller thinner caps. Better for signals.

https://www.jeepforum.com/threads/96...tures.1303589/

 

The PCM we got from flagship one looks like the one in your link. The original PCM looks like the one in the link below. I did open it up and looked over everything with a magnifying glass. I didn't see any broken joints, swollen caps or anything that looked burned or out of the ordinary which is why I waited so long to replace it trying to rule everything else out first. Let me see what FS1 wants to do, if they don't request it back I will gladly trade you for those plugs. If you want to get them anyway I will send you PayPal for them, might as well get the three at the PCM too. If you are able to do that try to cut them as far back as you can reach to give me room to splice. I'd like to stagger the splices so I don't end up with a big ball of heat shrink all in the same spot. I'd go get them myself but the yards around me only have a 1996 and 2000 which I think the wiring is different on both.

Not mine but this is what it looks like opened:
https://www.wranglerforum.com/cdn-cg...6-jpg.4520369/

 

As of right now I only have access to a 96 and 2001.

 

Crap, 2000 is when it switched to coil on plug right? That's what makes me think these connectors would be different from our 97 model.

 

I'm thinking instead of scouring the junk yards trying to find a good OEM harness, I'll just buy one of these Deutsch connectors since the wiring on both sides is jacked up anyway. This will give me the extended length to cut back the bad section of wiring and fix the broken connector all at the same time.

https://www.ebay.com/itm/26473681437...3ABFBM6uLRnMdl

 

Those two issues may be caused by the A/C on signal going to the PCM. Typically the PCM will turn on the E-fan and bump up the idle when A/C is running. A/C is on when the defrosted is selected. If your system is low on refrigerant the pump will not cycle on. Then you are left with high idle and E-fan running.

 

Thank you, I did verify multiple times that the A/C system is completely turned off. I do know that there is no refrigerant in the system as he has a leak in the compressor housing. This shouldn't matter with everything turned off though right?

We again smoke tested the engine for vacuum leaks through the brake booster hose and surprisingly there are none, all hoses the hoses and gaskets are holding.
The TPS is reading around 15% at idle which I've seen a few videos on youtube saying is normal, we can watch the % change accordingly when depressing the accelerator so it looks to be acting normally.
I confirmed that terminal A12 (if I remember correctly) Gray wire at the PCM has no continuity to ground, so the high idle circuit isn't driving the RPM.
We pulled the throttle body and cleaned it, verified the throttle blade is closing all the way, and replaced the gasket with a new one.
As a last resort we threw a new IAC at it with zero change. It is still idling around 1020 RPM in Park / Neutral and drops to around 850 in drive.

We took the intake piping off and ran the engine without it. It sounds like an excessive amount of air is going through the IAC circuit. I stuffed a rag in the IAC port and the idle dropped to 550 RPM and held there confirming we don't have a vacuum leak somewhere else causing this.

As of right now the only thing I can think is there is an issue with the new FS1 PCM programming making it idle this high, or we have to get the truck to a drivable state and put more time on it to where it can relearn the idle. I'm guessing we have 20-30 minutes total worth of idling in the garage and blipping the throttle with zero signs of the RPMS coming down at all. We've gone through several key on/off cycles and full 190-200°F coolant temps.

 

I'm not sure what pin or input signal the PCM is looking for with the A/C on, but it's possible we could have something grounded out similar to how the high idle circuit works even though my A/C is turned off at the dash. I will look at the FSM when I get home. Thanks for the idea!

 

Its possible the PCM is getting the A/C on signal even with it turned off. Possibly a wiring issue or the PCM itself. The symptoms point to that. Does the IAC move? There may be an IAC learn that needs to be performed. Check you service manual. Your new PCM needs to adapt to its new home. This may take a while.

In another direction, its possible the PCM thinks the engine temp is too high. Thus running the E-fan and higher idle.....

Are you able to read live data? If so you should be able to see if the A/C signal is on or off, the engine temp the PCM is receiving and IAC count. This information will give you clues to whats happening.

 

When I pull the rag out of the IAC port it goes wild for a second until it regains control, the IAC is definitely moving. Something is telling it to idle at 1020RPM as it is very steady and repeatable to that speed.
I only have a cheap code scanner that give some basic live data like ECT, RPM, TPS position, etc. I don't remember seeing anything about A/C in the available data but will check again.