Rough idle...

s1ngletracker · 03-15-2006

Hey, i've got some idling problems in my 92 AWD talon, which seem to be different than the usual ISC problem.

First off, the idle is really rough... its lumpy and doesnt like to rev in the low RPM range.

Second, the idle isnt relaly "catching" after I rev it. IE I release the clutch from cruising in gear at 3000 rpm, and it likes to go straight to 0 RPM and die if I dont feather the gas pedal.

So far i've replaced spark plugs and wires, to no avail. What else could be causing a rough idle? coils? some other ignition component? Oxygen sensor?

Has anyone had experience with this?

Thanks!

iceminion · 03-15-2006

Sounds to me like a melting ECU, had the same problem, and after replacing the ecu, all my problems went away.

s1ngletracker · 03-15-2006

reallly.... do 92 ECU's still have the capacitor leaking problem?

Steeltwo · 03-15-2006

check your biss to make sure it's there

s1ngletracker · 03-15-2006

it is....

s1ngletracker · 03-15-2006

i'd just like to repeat, does the 92 AWD DSM's have the same leaky capacitor/frying ECU problem?

SuperSleeper · 03-16-2006

Could be the TPS failing as well.
And yes, all DSMs can have leaking capacitors... it's always wise to replace them after a while... regardless what year it is.

s1ngletracker · 03-16-2006

Wouldnt I get an engine code if my TPS was failing? how do I tell?

Does anyone on here replace Caps?

TurboDomestics · 03-16-2006

http://www.dsmtuners.com/forums/showthread.php?t=191137

http://www.dsm.org/how-tos/tttt/tttt3.html

x-pride · 03-16-2006

Quote:

Originally Posted by s1ngletracker

i'd just like to repeat, does the 92 AWD DSM's have the same leaky capacitor/frying ECU problem?

Yes they do! Even Mitsue ECU in Geo tracker (1992-1997) have the same problem.

**JET** · 03-16-2006

I would do a boost leak test.

acidrumz · 03-17-2006

do a couple of these ....boost leak test, chk the ecu for leaks, chk the timing at base, clean your tb, ...to name a few

gluck
yy

s1ngletracker · 03-20-2006

alright... updates (if anyone cares)

-I got a new O2 sensor (it may have been the original and was pretty grimy!)
-cleaned TB (was pretty clean anyway)
-tested ISC (#1 coil is bad, resistance around 60 ohms, looking for another, post if you have one you can sell me) I think this may be the cause of my idle not "catching" on quick slowing of RPMs.
-checked/reset TPS (.90 ohms closed). Looks to be functioning fine.
-Checked EGR, not clogged, looks OK.
-Checked ECU, the caps have been replaced and appear to have been soldered on acceptably.
-I did find a missing stud in my exhaust manifold, and i found a leak on the other side. Need to remove manifold, easy out the stud, and swap on a new gasket. This may be contributing to the bad idle. Thinking about doing a 2G ported manifold swap at the same time... also, does anyone know who makes/sells a good aftermarket O2 housing? Might as well do that too.

Conclusions/further stuff to do:
-I think I may have some vacuum and boost leaks. I realized my car isn't pulling much vaccum at idle, i really hope its not compression but i'm going to test that.
-Plan for tonight/tomorrow is to pressurize the system to check for boost leaks.

Hopefully fixing the leaks will mostly solve my problem.

turbotalon1g · 03-20-2006

I care i have the same problem