Rough idle...
 

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!

Re: Rough idle...
 

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

Re: Rough idle...
 

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

Re: Rough idle...
 

check your biss to make sure it's there

Re: Rough idle...
 

it is....

Re: Rough idle...
 

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

Re: Rough idle...
 

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.

Re: Rough idle...
 

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

Does anyone on here replace Caps?

Re: Rough idle...
 

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

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

Re: Rough idle...
 

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

Re: Rough idle...
 

I would do a boost leak test.

Re: Rough idle...
 

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

Re: Rough idle...
 

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.

Re: Rough idle...
 

I care i have the same problem