1990 245. LH2.4 M47.


-Current problem is lack of power and poor idle. This just showed up the other day. I can drive the car, but it surges at light throttle and doesn't have full power at part or full throttle.

-After I reset the ECU the idle is low and crappy. It eventually turns in to a high or surging idle issue. I can repeat this. Thought it was interesting.

-If idling low and crappy, I can pinch fuel return line and bump pressure and idle goes back up. I assume even a good running 240 would increase idle speed if you skyrocket the fuel pressure to max....


Codes that have shown up in last few days:

1-2-1 (MAF). was from me unplugging
2-3-1 Lean or rich at part throttle
2-2-1 Lean at part throttle.

Cleared them out.

Got a 1-4-4 code later from EZK (signal from LH missing). Cleared it out.

NOW I have 1-1-1 on both but problem is still there.


I pinned out terminals at ECU plug per greenbook and all checked good there.

I am guessing the MAF or the ECU at this point....

 

the LH 2.4 ECUs' have a very low failure rate. not saying they never fail, but its sure not common.

Offhand, I'd say your symptoms could be from air leaks in the intake OR exhaust manifold, from a sticky idle air controller, or a bad MAF.

 

Took it for a DRIVE with MAF unplugged and found power.

Installed newish Bosch MAF today and now have buttery idle and all my power back!

 

does this car get damp inside in wet weather? like, is there condensation on the interior ? thats what was killing our old 240, dry it out and its fine. its a 1987 with a bajillion miles and a broken odometer, and I'm pretty sure the windshield is leaking due to some rust at the bottom corners.