Running real bad > optispark?

[scbird1]

I have a 93 z28 that has the original opti on it and I was having intermitant problems after it sat for a hour it would start fine but as you got going it felt like it was cutting out but would go away after 30 seconds of driving. I went to start it yesterday and it would barely run like it was fireing on a few cylinders. Did a code scan, nothing did a fuel pressure test holds a 40 with key on and slowly fades over several hours. I have good spark at coil but a weak spark at each plug that I could reach. I guess my question is do these thing just go out or do they sometime linger before they die? Thanks for any help, Mark

[Z Ya Later]

Sometimes they just die out, sometimes they die a slow and painful-to-you death. Rob (Shoebox) has a good testing procedure on his website to see if the PCM is seeing good pulses from the Opti. Click here for the test. This can help you to see if its the Opti causing the intermittent stumbling and what-not.

[scbird1]

Thanks for the link. I did the tests and it passed on all 3. The only thing was my ICM has a differnt layout but the wire colors were the same. I just hate to change it out and have the same problems but these are known to go out and its the original so whats another $300. and some cut up knuckles right. Looks like you have the same car there steve. Mine is a black m6 but I have put about 3 grand into the engine and another $1200 into the rear end 12 bolt with 3.73`s. Next is a vortec supercharger if I dont go broke. Thanks again for the help and the opti is on order.

Here is my other car> its the sleeper but slower then the Z

[Z Ya Later]

$300 for an Opti?? Where did you find that deal? The cheapest I could find was about $400 from Summit for a GM unit. Be sure its not the vented Opti for your own sake/sanity.

Sounds like you've done a lot of work there to yours. I mainly use mine as a daily driver...the GN is my toy lol. And nice lookin' 'Bird, real clean.

[Injuneer]

Check the other components of the ignition system before jumping to the conclusion that its the Opti. Coil, ICM, wires, plugs, check for corrosion on wire ends, check for damage or corrosion on the Opti harness connectors. Each of those items could be causing the problem, and each would be easier/cheaper to fix than the Opti.

I think the discount GM parts dealers that Shoebox lists on his website sell the unvented Opti for less than $400.

http://shbox.com/1/4th_gen_tech2.html#Dal_and_Jason

[scbird1]

I found a clearance of these non vented optis on Ebay for $280 GM part, new. I got the new opti in and had the same problem. I went back to the computer and rechecked my chip as this was the last thing that was messed with before the problem but the car ran fine for a few days. It fired right up. So im like wtf so I take it out for a little ride, rev it to 4 g in second go to third and no power
it just died so i coast to the side of the road, nothing I can see under the hood starts right back up and I made it home. Now im thinking I have a problem with my chip or wires to my cpu. On a good note I just got the 2007 GM performance parts catalog. I must have a LSX or the ZZ572/620 This engine is nuts 620 hp on pump gas NA

http://www.crateenginedepot.com/stor...93-P16C54.aspx

[scbird1]

Update, just pulled codes again and now code 41 has poped up. Open signal from distributor? Im just going to have a tow truck follow me where ever I go.

[scbird1]

Man this goes from bad to worse. Now I have a rattle that I think is in my cat and my exhaust note has changed to a much quieter note as I have the SLP loud mouth. Its finaly running good not great but I think I now have a abstruction in my exhaust. Still not sure what caused all this as code 41 has not poped up again.

[Jeff_in_Atl]

Did you look closely at the connector to the OPTI for corrosion? They are notorious for corroding. I had to replace mine.

[Injuneer]

DTC 41 refers to the white wire that sends the ignition signal to the ignition module. Check the wire and all the others that go to the ICM, and check the ground straps. I've also seen people claim that they solved DTC 41 by either replacing the Opti, or fixing the harness connector. When checking the Opti harness connector, make sure you check both the one on the Opti and the gray one on the bracket on the passenger side of the intake manifold.

A plugged cat would kill power at 4,000RPM.

[scbird1]

I did check all the wires but not the ones on the pass side intake. Thanks for all the help as I have a crappy helms book and it does not cover these parts well. I also have all new ground straps to everything as I dont think there is a bolt or nut on this entire car that has not been replaced. Only a few things like the opti,tps, were original. Mark

[scbird1]

Looks like its all good now as Its running alot better then it did before. Now to get rid of the cat. Well here it is in one peice.

[Z Ya Later]

Hey, that car looks awfully familiar