So I was having some idle/hesitation issues. My mech says that the stepper motor isnt closing up when it should, causing high idle. Also the hesitation / bucking is caused by lean mixture backfires due to the same.
He has swapped out steppers & everything runs fine, but after the truck is shut off, the computer commands the stepper to open up, in preperation for more fuel on starting. Then it doesnt want to close properly...
He is 95% sure it is the ecu, but is waiting for one to come in so he can swap them out & try a different one.
Also, there is evidence of the previous owner messing around with the ecu, probably to try to correct the same problem I have! There was a wire piggy backed into the ecu fuse.
So... Any suggestions as to any other areas to look at? If I can be 100% that the ecu is the problem ill fix it, but dont want to go chasing ghosts with hard earned $$$... I dont think the ecu is something that breaks down every day.
S.

 

Has your mechanic hooked up a scanner and pulled codes?. You could try cleaning the connectors on the ECU, as sometimes in extreme off-road use moisture can find its way to that location. But without codes it's kinda tough to nail down the problem.

regards,
Geoman
www.eurotekapg.com

 

There was no codes when the problem started. There Was however water & mud in the ECU (woops!). We cleaned the connectors & all that...
A code did pop up at one point but I cant remember what it was... Im trying to get ahold of him again to ask. They were all cleared without anything done about it by the previous owner...
He got ahold of me earlier & said that he swapped the ecu with one from a 98 in the shop & problem solved! So now im trying to find one that wont break the bank...
S.

 

I have a good used one out of a California 1997 Discovery for $250, but I'm not sure it can be re-programmed to work on your vehicle as I think there was a evaporative system change in 1998/1999 that this ECU does not address. Check with your mechanic and PM me if interested.

Regards,
Geoman
www.eurotekapg.com

 

I have one of a 96 discovery. What is the year of your vehicle?

 

Mine is a 99. The ecu needs to be from a 98/99, due to the evap system...
He swapped out for a 98 & it seems to have cleared everything up. But that was just a loaner so im still hunting for a new ecu...
S>