Daniel6718

ok heres the deal...friend just go this car together form a motor swap with new cam...(shortblock and head swap)

ok car ran perfect now hes got a moe bailey tuned bret bauer cammed stock motor...he got it back together and it had opti and map codes..(low res, and map was voltage low)

we fixed it by idleing it up(batt wasnt charging) and codes are gone

been running great for 2 weeks or so then started randomly dying because of no spark, give it 3-5 mins and it would restart and run...so i thought icm..but car finally quit and wont restart...got a new icm and car still didnt run..new coil still didnt run...so i checked and the cam sensor went bad...got a new opti and put it on the car ran great for a few mins and then died and wont restart...so i think it fried this opti too problem is why???

83tpi_3rd-gen(sri)

what kind of opti's are you using?

Daniel6718

it was a brand new gm one we just got an oreilleys one put it on ran for a minute and stopped wont start got another one and about to try it

Daniel6718

got another new one and no start...its like something was getting hot shutting down then finally ruined it....but its not icm pcm coil or opti?

83tpi_3rd-gen(sri)

how does the pigtail going to the opti look?

94SLUG

I have had very bad luck with opti spark as well! I bought a new GM from the dealer it was bad, bought another it to was bad, got a 3rd from dif state worked great! Just recently that one died, I had to order two this time as well... I noticed some of the new optis still have the brown tint to the plastic, and some are graphite the graphite has treated me better. Maybe luck maybe not..

Did you ck voltage under shoebox ref guide?

Daniel6718

im goana have to check according to shbox but i cant believe this so far...and opti pigtial is in good shape

Guest47904

Before you go throwing more money at the problem, you need to understand a few things regarding spark, the optical distributor and the engine shutting down. First we assume you are talking about the car in your signature that is OBDI. Second we assume your "SES" light works normally.

The opti has 2 sections, a low voltage feedback side and a normal (albeit weird cap) high voltage distribution side. Of the low voltage feedback signals, ONLY the low resolution signal on the feedback side will shut the engine down. Not the high resolution signal. This would render a DTC16 but will NOT set a "SES".

If this code is active, it will disable the injectors and fuel pump. So guess what, if you have consistent fuel pressure, you don't have a problem with the low voltage side of the opti. Understand?

A problem with the hi resolution signal of the opti WILL set an "SES" but will not shut anything off. So if you don't have an "SES" light, you don't have a problem with the hi resolution side of the opti. Unless of course the "SES" light is inoperative for some reason.

That leaves the high voltage distribution side of the opti. That only requires spark into and out of the opti. Pull the coil wire going to the opti out of the opti and check if for the presence of spark while cranking. If it's there, check each of the wires going to the plugs. Incidentally, just pulling the wires off the plugs and checking to the block for spark may NOT tell you the entire story. If for some reason the plug is not firing, this method will not detect it. That is why an inline spark tester is better. Capish? FYI only testing a few plugs can be wrong too. It only takes 3 plugs not firing to keep a SBC from firing up.

Savannah Dan

He said in the first line of his OP that it's a friends car.

Daniel6718

its was obd1 and first thing we did was pull coil and check for spark...no ses light...and does ahve fuel pressure and injector fire...

w tracked it down to a bad factory wire(wire losing connection inside the plug that goes into the coil) we had to get another one and soldier it in and all is good now...weird that it happened out of the blue...