victor.m

I know, I know, "another jumpy idle thread? check your vaccum lines and IACV", but I think I might have a bit of a different problem..

For beginners my 94 ej1 has a jdm d15b, automatic. The idle problem seems to occur sporadically, but only when the car is not in gear. What I mean by this is if the lever is set to D, D3, 2, 1, or R, it won't have the jumpy idle. But if I'm in P or N, the jumpy idle happens, some times, but not all the times. Sometimes it'll go a while without doing it and then start doing it all of a sudden. Somehow it seems that when I turn on the A/C it stops the problem with the jumpy idle, but I'm not 100% sure this is a solution, just seemed to stop it last night when I tried.

Anyone have any idea why it'd be jumping on Park/Neutral but not when in gear? Also, something else I've noticed is that my RPM will sometimes trickle down to below 600 and then the car will stutter a bit and jump back up slowly, not the abrupt 1000-1500 jump it usually does. Anyone know what might cause this? Something else that's weird is that if I slightly take pressure off the accelerator, the RPM will jump way down and then come back up a lot, seems kind of too much of a drop for a slight release of the accelerator, and only happens at low RPM (sub-2000).

Appreciate any input you guys might have, and thanks in advance!

victor.m

bump?

94EG8

The only thing specific to an automatic i can think of is the shift interlock under the dash (blue box) it ties into the ECU, this is what makes it so you can't shift out of park unless your foot is on the brake pedal, the other part of this is that the car must be at idle. I destroyed one of these modules a week before i did an auto to manual swap on my sedan, (its a long story, but in a nutshell i accidentally drove the clutch pedal through it) I took it apart and bridged all the traces i broke and put it back together and it worked fine in terms of letting me take the key out and allowing me to shift out of park, but the car had similar idle issues until i got the manual tranny and ecu in.

victor.m

Thanks for the tip dude, gonna check that out.. someone on clubcivic apparently has the same problem but the other way around, he has a b16 auto. Unfortunately can't do much on the car today, tropical storm and all here in FL!

94EG8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by victor.m &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the tip dude, gonna check that out.. someone on clubcivic apparently has the same problem but the other way around, he has a b16 auto. Unfortunately can't do much on the car today, tropical storm and all here in FL!</TD></TR></TABLE>

Actually mine may have been causing me trouble in gear, to be honest its been a long time and i forget, but it definately had idle problems that were related to that interlock box. I'd pick one up at a junkyard and try it.

UgP

I have the same exact problem victor. have you looked into if it is the iacv or not yet? i'm not sure what my issue is. my car was sitting for a few months and i finally go it back running but with a messed up idle.