Right I have a Jeep in for drivability fault. Stored codes when dropped in related to a faulty glow control module and an implausibility on the MAF sensor. The glow plug module was tested and found to be faulty and replaced along with the glow plugs as on had shorted possibly causing the module to fail. The live readings checked for MAF and for the duration looked OK. The intake was smoke tested and an air leak found in the intake system. The offending pipe was replaced. Great I thought fixed, WRONG! The car was taken on road test and all fine for about 10 miles then the performance problems came back. Lack of power and what seemed to be timing issues with the engine as it was coughing and kicking.

Back in the workshop live data was pulled back up and found to show that the MAF was all over the place. Going from 8kg/H to 60kg/H on idle. I was expecting about 50kg/h but it was up and down like a yoyo. I scoped the MAF sensor and found that at idle it was showing 2.37kHz on idle and up to about 8kHz when revved. The output was stable on idle only deviating when the EGR was actuating. I got no deviation on this like I did on live readings so next step is to find the ECU and check the wiring to the ECU I.E. see if the same frequency is at both ends of the cable.

Anybody know where the ECU is on one of these as I have no real data for this lump. ESi is taking me to Merc and not coming back to Jeep. Also have these any known issues with ECU's as if the wiring checks out I think it could be a duff ECU.