If ya got coil pack's then ya are only using the one side to fire the injectors,correct?

 

I believe that is correct but if the opti craps out then it will send you a bad signal, that car has an ignition problem somewhere, that sound i've heard from my own car plenty of times, I would take that opti off and replace it. I've had them crap out after only being a month old. I could have a good cap and rotor but the backside you can buy at autozone for 130. I'd say that's the problem, nothing else is wrong, coils good, plugs good, wires good, tune/pcm is good, nothing mechanical from the sound of it. I will correct myself, you don't need the cap/rotor, it doesn't send the signal. You need that bottom piece of the opti.

Also were you getting off the ground on stock tires? or drag radials?

 

If there are coil packs the opti has nothing to do with firing the plugs....
The OTHER part is firing the injectors and no need for a cap and rotor.

 

Yeah I checked and all the coil packs are firing.

Was who getting off the ground? Not me...

I hate to spend that much money on an Opti unless I can prove that it is in fact the problem...the signal side doesn't really go bad...and I can't see it going bad all of a sudden. Will a scanner tell me anything pertinent?

 

Sometimes the opti will fire a code and sometimes it won't. Eliminate everything else and then do the opti. If everything checks out, then replace it. Or, find someone with an old/extra one you can borrow to pop on and see if it fires up and runs good.

 

Borrow/rent trailer, take car to A&S Automotive in Forth Worth (TX), leave car and credit card, come back in a week or two, get a perfectly running dyno tunned car. Good Luck.

 

Replace the optical sensor inside the opti and see what that does.

 

Boy I remember filming those drive bys at 3am! Thing definately sounded much better then than the videos of it now.

It's definately rich now and it sounds like the plugs are good now too. I'd get that A/F adjusted so you don't have to go back and redo the dam plugs.

Bret

 

I've had the back part of the opti go out plenty of times and misfiring just like your car does, you've basically eliminated everything else. Just because they are firing doesn't mean they are firing at the right time.

 

What's that loud clacking noise?

 

Comp Pro Magnum roller rockers...I hope!

Haha yeah that was funny...no ins, no reg, no inspection...and WAY too many cops out! Yeah it sounded badass then...now it just sounds, like, well...***

So you think it's just Rich? What can I look for that may have changed to cause it to run good before then all of a start running rich?

Looks like a few votes for replacing the optical side of the opti...but is there anyway to check it to verify?

I've got a truck & trailer...but I don't think I have the money to drop it off somewhere...

 

I think it's rich and fouling out the plugs, so it runs well at first then goes down hill.

I have a buddy up here who knows about optis and how to check them, i'll get his e-mail and send it to ya.

Bret

 

The only way I know to check them is to remove them, and if everything else is fine, it leads you to it. It it's running too rich, that's either the tune, o2's (considering no codes then that's not it), and/or the air is restricted somewhere.

 

Are you sure the preload on the rr's is set right? Could a couple be too tight and holding a valve or two open? Im sure you probably have that right as much as you've been working on it.

The other thing that causes similar symptoms in engines I work on is intake leaks. Maybe put a vacuum guage on there and see what it reads. Maybe an intake gasket is leaking? That can cause irratic idle, poor throttle response, and make it stay at a high idle after a rev.

Other than that Id say timing. As long as your timing chain didnt slip and screw up valve timing, it would probably be the optical sensor screwing with ignition timing.

OPTI TEST: http://shbox.com/1/4th_gen_tech2.html#opti_test I dont know how much this will help since yours starts, but you may be able to pick up a weird signal from one of the opti outputs.

 

Ive got a couple spare optical sensors laying around the house if you want one. No charge