4.0 Questions

**dadstoy** · 08-19-2006, 12:45 PM

Ok, I thought this would be the best place to ask some questions about the 4.0/auto I just installed in my Jeep. The donor was a 95 Grand. It was involved in a roll over accident. I have the motor and tranny installed in my YJ, but am having issues. Finally got the start circuit figured out and it runs, but only for about 10 seconds then dies.

This is at idle only. If I apply fuel, it will stay running, but run rough. Let off the gas, it dies.

I am not sure if the Grand had the security on it or not. I won't be able to find out until Monday. Someone suggested the TPS or the CPS. Any ideas? Any help is greatly appreciated.

Dave

PugetHound · 08-21-2006, 04:33 PM

did you swap the ECU also ?

**Woody** · 08-21-2006, 10:08 PM

I bet the ECU has a security system built in. You probably don't have the proper wiring from the BCM (body control module) to give it the signal it wants to confirm the alarm has been disabled.

You may have to order a new ECM without the security.

PugetHound · 08-22-2006, 10:39 AM

An ECU from a manual shift vehicle plugged into an auto would do the same thing I think.

**dadstoy** · 08-22-2006, 12:26 PM

Turns out it was the security/anti-theft that was the problem. I tried a ECM from a YJ 4.0/auto and it ran fine. I ordered another last night.

Thanks

PugetHound · 08-22-2006, 12:34 PM

Glad you fixed it !

08-21-2006, 04:33 PM	#2
PugetHound Registered User Join Date: Jul 2006 Location: Olympia Washington Posts: 174 Profile Gallery Classifieds My Jeeps	did you swap the ECU also ?

08-22-2006, 10:39 AM	#4
PugetHound Registered User Join Date: Jul 2006 Location: Olympia Washington Posts: 174 Profile Gallery Classifieds My Jeeps	An ECU from a manual shift vehicle plugged into an auto would do the same thing I think.

08-22-2006, 12:34 PM	#6
PugetHound Registered User Join Date: Jul 2006 Location: Olympia Washington Posts: 174 Profile Gallery Classifieds My Jeeps	Glad you fixed it !