Doesn’t run with Maf connected, checked all the possibilities. No changes, runs right with maf disconnected I understand the purpose. Have changed maf from a known running D1 no change. Bought new Aftermarket still no change. It’s a the mechanic shop and tech is says bad maf he replaced with another new maf and test drove 10 miles called said it was good to go. Picked up this morning was assured it was done It wouldn’t get out of its own way. Still in shop tech says he got a bad MAF. Any ideas out there? Thanks

 

First, the Disco will only accept a Lucas MAF, aftermarket are junk Chinese knockoffs made to accept your dollar and nothing else. If they do work it isn't for long. Stick with Lucas, the known good swap you tried. Do you have another ECM you can swap into the Disco? If not go to a pick and pull/bone yard and yank one from a 98 or 99. Now try the swapped MAF. If that fails you really need to dig into the wiring in between the two parts to find why it's not reading the MAF. Usually just pin corrosion. The fact that the truck ran like crap with an aftermarket is not a big surprise but it's not conclusive it's the MAF, the ECM may not even be seeing one connected......eh.

 

4 years ago I replaced the MAF with Aftermarket and it lasted till a few weeks ago it hadn’t skipped a beat. Remembering that it was just a plug and play however now after 3 mafs it’s not right. I agree with your comments, my tech says all the electrical signals are correct and pointing to maf. It was suggested that harness to the maf could be faulty. You mentioned that ECU may not see the maf. Unplugged maf no stall, plenty of power, only stumbled to start. Confused

 

When the MAF is disconnected the ECU reverts to a A/F table that will allow the motor to run although it will run rich. The Rave doesn't state this but most modern engines default to limp home mode when the MAF fails. If it was mine I would hit the MAF's wire loom plug with electronic cleaner and then apply a dab of dielectric grease to the pins. The dielectric will bridge loose female pin holders. I'd try on your known good MAF again and see what pops. The MAF return signal is in milliamps so any loose connection is going to have an effect on signal. I don't know what brand the shop installed which failed but I assume aftermarket.

 

Could the alternator not be giving the ECM the right signal to communicate with the Maf? Tech says MAF is not problem, tried another maf from running D1. Is the tech close or not?

 

ECU had burn smell when removed and opened up. Replaced with a known good unit with matching alarm it immediately ran correctly. Power restored also replaced Maf and noisy alternator. D1 is back in business. 😎

 

Glad it’s resolved. Sounds like the ECU and the other equipment was just maintenance items.

 

Replaced the ECU with alarm now the key fob is not working is there a quick fix or did the tech forget to program hand sets. (Fobs)?