Please help optispark woes
Thread Starter
Advanced
Joined: Dec 2020
Posts: 80
Likes: 4
From: New York City
Please help optispark woes
So I just replaces the plugs and opti on my 94 lt1. Car dropped to 0 revs on the highway so had it jumped. Worked for 30 mins then died again. Had it towed to a shop and they replaced the opti. It'd start up fine no roughness but any acceleration would cause it to backfire and wreak of gas. The shop thinks it might be fuel injectors but that makes little sense to me since it idles well. The shop tested the spark and all 8 passed but the injectors would die after a few seconds of revs. Any clues as to what this might be? The gas is about 3 months old since it's been sitting this winter, plugs and opti are oem replacements, and it's run fine until this incident. Thank you in advance!
Drifting
Joined: Nov 2018
Posts: 1,783
Likes: 579
From: Mays Landing, NJ
So I just replaces the plugs and opti on my 94 lt1. Car dropped to 0 revs on the highway so had it jumped. Worked for 30 mins then died again. Had it towed to a shop and they replaced the opti. It'd start up fine no roughness but any acceleration would cause it to backfire and wreak of gas. The shop thinks it might be fuel injectors but that makes little sense to me since it idles well. The shop tested the spark and all 8 passed but the injectors would die after a few seconds of revs. Any clues as to what this might be? The gas is about 3 months old since it's been sitting this winter, plugs and opti are oem replacements, and it's run fine until this incident. Thank you in advance!
Le Mans Master
Joined: Feb 2000
Posts: 9,060
Likes: 214
From: Epping NH
Gas isn't the problem, most top brand gas will last 6-12 months even without stabilizer...although if you have water in the gas that would cause issues. As mention pull the codes https://tech.corvettecentral.com/201...trouble-codes/ for a start. Although I'd be a bit surprised if the shop you brought it too didn't do that step.
Thread Starter
Advanced
Joined: Dec 2020
Posts: 80
Likes: 4
From: New York City
Why do you think it is the optispark? Obviously your shop was incorrect in their diagnosis since still having issues. Since you are getting spark now was the spark checked before they changed it out? Did you pull any codes? Since you do have spark it sounds like the next logical step would be to check fuel pressure.
Thread Starter
Advanced
Joined: Dec 2020
Posts: 80
Likes: 4
From: New York City
Gas isn't the problem, most top brand gas will last 6-12 months even without stabilizer...although if you have water in the gas that would cause issues. As mention pull the codes https://tech.corvettecentral.com/201...trouble-codes/ for a start. Although I'd be a bit surprised if the shop you brought it too didn't do that step.
Drifting
Joined: Jun 2020
Posts: 1,355
Likes: 396
From: Northwest Ohio
Check your own codes…. It literally will tell you “optispark no worky” rather than blind guessing. I think a lot of perfectly good optisparks end up in the trash. Make sure you get the old one back!!!!!!
Just because it starts now it could actually be the ICM/coil and wires being jiggled or having lower resistance.
Any other diagnostics should involve pulling codes and the shop should have an OBD 1 reader to check O2 sensor readings etc… check fuel pressure etc
you also mentioned “having it jumped” so could be bad grounds or again weak coil or ICM…or you have a bad FPR
who knows, get codes and don’t let the shop throw parts at it
Just because it starts now it could actually be the ICM/coil and wires being jiggled or having lower resistance.
Any other diagnostics should involve pulling codes and the shop should have an OBD 1 reader to check O2 sensor readings etc… check fuel pressure etc
you also mentioned “having it jumped” so could be bad grounds or again weak coil or ICM…or you have a bad FPR
who knows, get codes and don’t let the shop throw parts at it
Heel & Toe
Joined: Apr 2021
Posts: 17
Likes: 0
From: Seneca Falls, NY
I had the same problem with my 92. I replaced the opti because the water pump was leaking on it and I thought it has to be that. But it ran like yours once it was done. I then replaced the fuel pressure regulator and runs like a champ.
