Sid

im stumped, new to the site sorry if its hard to follow the post, got a 93 LT1 camaro, not much aftermarket done to the engine other than an slp intake and aluminum elbow, got it about 6 months ago, ran like a dream other than ses light due to bad coolant temp sensor in water pump, made it run rich, replaced it, couple weeks later opti went out, put a new opti, msd coil, and ICM on it, couple weeks later flexplate snapped and also ate starters nose cone, and on top of that the opti went out again, fixed all that, drove for a couple days, ignition switch shorted out causing QDM fault 1 and also no cooling fans, blower motor, or turn signals, fixed that drove three days ran perfect, sittin in a parkin lot after driving it all morning and it just shut off didnt sputter, fired right back up did it about four times and didnt do it anymore the rest of the day, next mornin didnt want to start finally did after about five minutes, drove it to town sittin there idling and it died again and wouldnt restart, towed it home, put another opti in and it fired right back up but was dieing like it was before didnt drive it next mornin went to start it and do some troubleshooting but wont start!!!! thinkin maybe the opti harness, but want some help and ideas, thanks in advance

Injuneer

Welcome to CamaroZ28.com! Always great to see another LT1 owner on the site.

You need to post "tech" questions on the correct technical forum. I'll copy your post to "LT1 Based Engine Tech".... lots of knowledgeable people there.

You need to scan it for codes, shorting the ALDL pins to flash the codes on the SES light.

http://shbox.com/1/dlc2.jpg

shoebox

What kind of diagnosis are you doing before replacing stuff? You can find opti and harness info here. When you say doesn't start, you need to be more specific (ex. won't crank, cranks but won't start, etc.)

And, yes, a post that is a long paragraph with nothing but commas for punctuation is hard to follow. That can make people more inclined to just skip over the post, rather than reading it. Something readable makes your post more likely to get responses.

Sid

Now that i look at the first post it is hard to follow, sorry guys.

No codes, all it flashes is code 12. The car just cranks, ive used a spark tester and it shows no spark. When it would idle i had a fuel pressure gauge hooked to it and read about 48 pounds at prime and 40 at idle.

I pulled the ICM back off and it tested good and i wouldnt think it would be the msd coil since its only a couple months old.

Injuneer

Based on the number of failures I've seen reported here, I don't think the MSD coil is as reliable as the stocker.

When you replaced the Opti (twice already) what brand did you use? What failed in your original Opto to make replacement necessary? What failed in your first replacement to make a second replacement necessary? Have you been applying Loc-Tite to the rotor screws in the Opti?

Sid

im using an a1 cardone opti, and its been warrantied with the same brand for the other two. The first one i had a heater hose rupture and then about a week later it just died and i pulled the cap off and the rotor was corroded, and the second one im not sure but when you would crank it the tach would jump to 7 grand and bounce inbetween 5 and 7 grand.

Ive been buying a complete opti so ive never took the cap or rotor off i just put the assembly on.

Injuneer

You are buying poor quality. Even the good ones - AC Delco, GM Performance Parts and Delphi - need the rotor screws reset with Loc-Tite.

Sid

i took your advice and bought a new AC Delco opti and harness, so i should still pull the cap and rotor off to loc tite the rotor screws on the AC Delco?

RamAir95TA

Yes, that's correct. Do NOT overtighten the E4 inverted torx screws when you reassemble it.

Sid

any special torque pounds? or just tighten using my own judgement?

RamAir95TA

I would say MAX 30 to 36 in-lbs.

Injuneer

Did you follow Rob's suggestion on testing for Opti performance? What diagnostics did you do to determine you need a new Opti? Not clear from your posts.

Sid

I havent had a chance to measure volts and resistance due to my meter being at work in another guys box, but i put my old oem coil back on which i know is good and had the icm tested again and it shows good on both high and low rpm levels. I put a spark tester on all four wires from drivers side and have no spark, so that has to mean opti or harness right? Or is there something else in the ignition system that could be causing a no spark problem?

RamAir95TA

So you're saying you have spark out of the coil but not out of the opti, is that correct?

Cap/rotor or coil wire connection would be my guess.

Sid

I have fire to the opti but not out, i replaced the harness and still wouldnt start so when i get a day off ill replace the cardone opti with the delco opti i got