idle problem - Third Generation F-Body Message Boards

mystikkal_69 · 10-25-2002, 01:40 PM

my damn iroc(88' 350 TPI) even after replacing the cap, rotor, wires, plugs, injectors, pickup coil, O2 sensor, MAF sensor and all intake gaskets my car idles kind of rough. it sounds like it has a little miss to it. it has had this little problem for a while. before i started changing out parts. i really hate it. what else could cause this rough idle? i'm trying to track down this damn problem. thanks people.

RMK · 10-26-2002, 11:51 AM

Have you tried cleaning the IAC?

mystikkal_69 · 10-26-2002, 04:34 PM

i "rebuilt" the throttle body(new gaskets + cleaned). the IAC is clean and lubricated. thanks for the reply

. can a loose timing chain cause these symptoms? that's what i'm leaning towards right now.

72LT1VETTE · 10-27-2002, 01:15 AM

Did you clean the IAC plunger and seat or only the plunger.

Benny · 10-27-2002, 01:27 AM

Did you check your distributor, I realize you change your module, cap, rotor but the distributor itself could be bad. just a thought.

A friend of mine had the same kind of problems with his '87 350 IROC, changed distributor and problem went away.

mystikkal_69 · 10-27-2002, 07:37 AM

72,
the IAC plunger and seat were a part of cleaning/rebuilding

.

Benny,

that's a thought. the distributor may be mechanically worn. i just thought that timing since the damn thing has 100K on it. those stockers get loose afer maybe what, 10k? i will have to look into that as well. what about the igniton coil? could it be going out? or how do igniton coils go out? all of a sudden or progressively? symptoms? thanks again guys.

Vader · 10-27-2002, 09:07 AM

You might want to consider an injector problem. Perform a power balance test by isolating injetors and you might learn something.

mystikkal_69 · 10-27-2002, 11:01 AM

Vader

forgive my ignorance but how do u perform a injector load balace test? disconnect one injector at a time listen to the engine & see if it run's differently? i would hate to have a bad injector since i just replaced them

should i perform the ohm test on the injectors? what are valid resistances for the injector coils? cold? hot? thanks again

Benny · 10-27-2002, 12:55 PM

Sometimes on injectors you can take a stesescope (like a doctors) and put the pointer on the injector and listen to the pulses (like a heartbeat) this could give you some kind of indication. You can buy an engine stesescope (spelling??) at any auto parts store for about $15. As for the coil these things usually go out at once, usually not progressively. Good luck.