Hesitation and stalling

[SilverXJ]

Where is the primary resistance taken from? I tested the pins and I don't recall what their values were, but I got nothing from the spark plug boots themselves. What is the testing procedure for the ASD relay?

I'm really leaning toward the PCM having an issue. I had unplugged the MAP and IAC and the PCM never set a code.. I really didn't pay attention to that until today when I pulled all the O2 sensors and sims and the PCM didn't say anything about it. it had 0 O2 sensors plugged in and it didn't throw a check engine light.

[Jeep4xb4u]

I'm not sure what they mean by Primary resistance. I have a 2002 WJ 4.0l sitting in the garage right now i can compare some stuff for you if you would like. But here is exactly what they state in all data.

This would be odd if this is the problem but i guess anythings possible @ this point. They do state that your coil rail gets it power directly from the ASD relay. AKA Automatic Shut Down.

[SilverXJ]

I can't figure it out. Its going to the dealer tomorrow. Lets see what they say.

[SilverXJ]

Dealer thinks the PCM is damaged. I also spoke to the company that programmed it and they believe the same thing. I think the most obvious thing is that no codes were throw when the O2 sensors were unplugged.

Anyone have any luck with companies that sell PCMs?

[dwg86]

I haven't bought any PCM's lately. Any idea what caused the PCM to be bad?

[gradon]

So if you bought another pcm, kolak would tune it for free?

[SilverXJ]

I think the PCm went bad when the battery drained and I jumped it a few times.

I talked with the person that kolak uses for the program. He would reprogram a new PCM for $150. I'm going to hit kolak up about that though. He also though that the PCM is faulty.

[SilverXJ]

I went back to check that the O2 sensors didn't give a code when disconnected. They didn't. I let it run for 10 minutes after I unplugged the O2 sensors an no code nor light came on. So, it seems there is a problem with the O2 circuit in the PCM

I got a used PCM and dropped it in. It started up then died. The stupid sentry key system is telling the PCM to kill the engine. From research the Sentry key is looking for the correct SKIM key stored in the PCM, which isn't present.

Now, the fun part is that there was a Jeep dealer across the street from my storage unit. It is one of the Jeep dealers that DC dropped. They still have DRBs for diagnostic purposes. I took it to they and they came tot he same conclusion, that the PCM was some how damaged between the battery being drained and the jump starting. Now, because they are no longer a Jeep dealer they can't change the settings in the used PCM for me. The DRBs require an internet connection to DC for that. So.. I now get to drive 45 minutes on a faulty PCM to the nearest Jeep dealer.. nice huh? Thank you DC.

So I have an appointment to get the PCM reset on Monday, which I need to take off work for.

[SilverXJ]

The dealer programmed the PCM today.. guess what... it didn't fix the problem... What now? Everything else checks out but the coil rail.. the O2 sensors seems to be operating correctly as well. Could the coil rail cause this? What about the ignition capacitor.. which I am not even sure of its function.

At least I have a spare PCM now.

[SilverXJ]

Pulled the plugs and they were black with carbon build up.

[George Dickel]

What ever came of this???

[SilverXJ]

It was the Comp Cams cam going flat. Don't know why it would cause a hesitation of that sort, but it did.

[Team Willys]

Hey man, I am brand new on this site. I have built several 4.6/4.7 Strokers, but I am new to the whole OBD2 fuel injection thing, the others I have built have been in Carbed YJs...

Anywho, I am currently building one for a 2000 XJ. It will be a pretty mild build, a Comp XTreme 4x4 cam, stock intake w/ 62 mm TB, banks header, 24 lb mustang injectors, and a full 2.5" exhaust with only the first 2 cats.

Im glad you got your issue figured out, but I have a simple question for you: Before your cam failure, did you have any special electronics to make your engine run correctly? I noticed in you mentioned some sort of piggy back? What is this and was it required for you to get it to run properly? Did it run ok before you put the piggy back on?

I am kinda on a tight schedule and just wanted to know if it will even run decently without computer mods. Just wanted to know if it would run well enough to be able to drive it.

[SilverXJ]

The Apexi piggy back was only for fuel correction. Nothing else was needed.

[dwg86]

Hey man, I am brand new on this site. I have built several 4.6/4.7 Strokers, but I am new to the whole OBD2 fuel injection thing, the others I have built have been in Carbed YJs...

Anywho, I am currently building one for a 2000 XJ. It will be a pretty mild build, a Comp XTreme 4x4 cam, stock intake w/ 62 mm TB, banks header, 24 lb mustang injectors, and a full 2.5" exhaust with only the first 2 cats.

Im glad you got your issue figured out, but I have a simple question for you: Before your cam failure, did you have any special electronics to make your engine run correctly? I noticed in you mentioned some sort of piggy back? What is this and was it required for you to get it to run properly? Did it run ok before you put the piggy back on?

I am kinda on a tight schedule and just wanted to know if it will even run decently without computer mods. Just wanted to know if it would run well enough to be able to drive it.

I don't have an air/fuel ratio gauge on my 2003 stroked TJ, so I don't know what the stock computer is doing, but it runs good. Spark plugs look good(light tan), no pinging. You should be good with the stock computer.