SonnyinVA

i'm still trying to diagnose if it really is my opti or not...
i keep getting wierd and confounding symptoms...
i get a kind of rough, searching, idle with no accessories on, if i turn on the AC it wants to try to die. it seems to run ok at higher RPM but if i'm in low RPM's it stumbles... ok that sounds like opti right?? i checked plug wires at the plug end but can't see diddly at the opti end... they all seem to be on there good and snug.

but check this out!!!

i pulled the ECM fuse for a minute, thinking that maybe i would reset it and just see what happens... after that it ran good, even ran ok for a few minutes after i turned on the AC... whereas before it tried to cut out under load... well now i notice that the AC is only coming out of the defroster and floor vents... the climate controls seem to be working fine but can't get it to switch off of the floor/defrost... after a few minutes it started acting like it wanted to die again. and when i was riding around my neighborhood really slow, i could feel a HUGE difference in the car when i turned the AC on and off... turn it on and feels like somebody hit the brakes..., off and it feels kinda ok...
i think the "AC loading = running like crap" just supports the opti conclusion but what about the not switching off of the floor /defrost??
driving me crazy...
don't want to just replace the opti to find out that's not it and i blew 500 on a opti and waterpump...

SonnyinVA

come on, i know there are opti-pro's in here...
ttt

merrick

I am no opti pro but I think the opti is not the problem. Disconnecting the battery is the right way to reset the ECM, but pulling the fuse may work too? Maybe the TPS out of adjustment.

Ruby6spd

I can describe my opti situation to you and see if it fits,

About 2 years ago I started the car and it idled fine, pulled out of the drive way and drove easy until everything warmed up, the second I put any load on the engine or accelerated hard it began to stumble, it would rev to redline if it let it get up there slowly, but the second I nailed it it would stumble and backfire,, almost like a cat was clogged,, I then realized that my waterpump sprang a leak and took the opti with it, I replaced both and everything is fine.

It sounds as if your having the same symptoms.. anytime your putting load on the engine it falls off via the a/c

as for the a/c not coming out of the main vents I have no idea,, weird electrical mystery on that one

hope this helps

Rick92

My opti demise was the same as rubys :chevy

SonnyinVA

yeah, but mine is all low RPM problems... after about 2000RPM it seems to run fine, and now it really doesn't run that bad at idle either unless i turn on the AC... it actually runs pretty good as long as the AC isn't on...

could it be a voltage regulator??
maybe the AC is drawing too much or something and the reglator isn't providing enough for AC and spark??
am i reaching on this idea?

where is the voltage regulator in a 96? is it in the alt?

C4TOMCAT

Have you checked for a vacumm leak or the "t" fittings being cracked. just another idea to check out without spending any money.

Danger Dave

Sonny,
The symptoms are exactly the same in my car after changing the opti, plugs, wires, fuel filter, clean IAC, new computer (which was bad). When Leo went to BG-CF3, he spoke with Gordon Killbrew who said it sounded like plugged cats. I haven't investigated that yet, trying to find someone local who can drop my exhaust and gut my cats.

You might want to explore that avenue. Your symptoms are exactly as mine, once the RPM's are up she runs okay. When it's below 1800 RPM she just runs like crap. My mileage is way down too since I can't run in OD on the freeway. Maybe we can have a cat guttin party at Greg's house.

SonnyinVA

well, i wanted to get rid of the cats anyway, but i have 2 high flow catco cats installed in the true daul exhaust... so i don't know if they are the culprit...
do you have the AC problem too dave?? AC makes car want to die?

i do know exactly when the problem started... (mine wasn't gradual like some peoples)
it was immmediately after a LONG smokey burnout, all the way thru first and second, in which i hit the rev limiter for a few seconds... (it was sweet)
that's why opti makes sense... i figured it just was on the verge of failure and the high RPM's pushed it over... (but some other symptoms don't make any sense) for example, can anybody explain the AC problem??? i mena, i know the load maight be too much, but waht about not switching vents?? is that just a coincidence? and the fact that it still seems to have good power at high RPM's?? i would think if the opti was dying, especially under load, that high RPM's should have the same effect... but it still tachs up very fast.

of course that is just by the butt meter, might show a difference on the dyno...
maybe i should make another post, just asking for diagnostic help... i think so many people are tired of the opti subject it makes them not read opti posts...

R23HTC

I've only had one car with a clogged cat. It would run fine at lower speeds but couldn't do anything much above idle.

Danger Dave

Well if you have aftermarket cats that's probably not the deal. When i put a load on the car (AC On) or at 1800 RPM or less especially at 55-65 MPH in OD she doesn't run right. There were a few opti's in the C4 parts section for $200, maybe you should just get one of those and a spend few hours and try and see if that is it.

Could it be 02 sensors?

Sticking/misfiring fuel injector?

Ruby6spd

I would get it hooked up to a scanner and see what the o2 sensors are saying, you may find that when you loading the engine some cyclinders aren't getting spark, or spark at the wrong time. I believe that when a opti goes bad you essentially have the spark jumping around inside the unit and not getting directed to the correct plug, I would imagine this would have the potential to make all kinds of weird electircal things happen..

Check all your sensors and codes first, but I would guess you will find yourself replacing that wonderful opti in the end..

Kdrhpe

It sounds to me like you have a vacuum leak