Hi all,

I've got a 1990 DA (originally OBD0) converted to run an OBD2a ECU with a HA Motorsports conversion harness. No MIL during driving, but in service mode I scan code 14 and 20 and suffer from a creeping idle that goes from whatever base idle should be (850) up to 1200rpm. I swapped IACV's, same problem. IACV definitely working. Led me to to believe my problem is without an ELD, the ECM is getting 0v, and asking the alternator for full field, and thus my idle is creeping up.

I'm trying to figure out how to deal with this situation. Adding an ELD seems very complicated. Fooling the ECU seems easier - perhaps feeding it 2.5v which is the middle of the accepted 0-5v range I've read.

Curious if there is anyone knowledgeable on this out there that could help point me in the right direction as most old threads don't lead to any solutions and I haven't found anyone out there with an OBD2a ECU in an OBD0 car without ELD.

Thanks!