93 Opti-spark issue
Thread Starter
Intermediate
Joined: Apr 2013
Posts: 45
Likes: 8
beware. the summit racing optisparks do not have the mitsubishi optical sensor either.
you can add a 95-96 vent harness to a 92-94 optispark by putting on a 95-96 optispark cAp which has provisiona for one of the vent hoses (the air inlet).
you then drill out one of the 3 weep holes to 1/8" and epoxy the other 2 shut) on the base of the unit and use that as the vacuum source.
this is how you retrofit the vents onto a 92-94 optispark.
you can also put on a 95-96 optispark but you need to change camshaft and timing cover. for me, it wasnt a lot of work bc i was putting in a new cam anyways.
you need to find an oem acdelco optispark with mitsubishi optical sensor and add vents to it !!!
look on ebay ! or post here in the parts section that you are looking to buy.
you have to trust me: you are better with a 50000 miles used oem optispark (with mitsubishi sensor) vs. a brand new chinese or msd optispark
you can add a 95-96 vent harness to a 92-94 optispark by putting on a 95-96 optispark cAp which has provisiona for one of the vent hoses (the air inlet).
you then drill out one of the 3 weep holes to 1/8" and epoxy the other 2 shut) on the base of the unit and use that as the vacuum source.
this is how you retrofit the vents onto a 92-94 optispark.
you can also put on a 95-96 optispark but you need to change camshaft and timing cover. for me, it wasnt a lot of work bc i was putting in a new cam anyways.
you need to find an oem acdelco optispark with mitsubishi optical sensor and add vents to it !!!
look on ebay ! or post here in the parts section that you are looking to buy.
you have to trust me: you are better with a 50000 miles used oem optispark (with mitsubishi sensor) vs. a brand new chinese or msd optispark
Race Director
Joined: Sep 2001
Posts: 14,664
Likes: 749
From: NEwhere Ohio
OK I am almost resolved that i need to replace this Opticrap. Now where and what kind. You say OEM Delco but that was what came with it and went bad. Still feel the same? MSD proffers that they have an updated unit that will last and perform better (twice the price as others though). I don't mind paying if this is the last one, I am so done with this distributor. I want to drill a hole in the intake and put in a Mallory duel point distributor. You really think used is a good way to go?
1. because it doesnt have a vent (design flaw). ive explained how to add one to make it reliable
2. the seals shrunk/cracked and allowed water intrusion. i take it apart and apply rtv silicone as a 'backup' in case the seals fail. also note the vent in #1 would suck out and keep the insides clean and help out in this situation
the non-oem units without mitsubishi optical sensor have electronics that cant stand the heat and tough operating environment.
you said something that caught my interest: that msd has an updated design or something.
to be honest, i havent heard lately here about all the msd optispark failures that i used to.
that said, id still rather have a working fine 50000 mile used OEM ac delco optispark (that i took apart, cleaned, inspected, added a vent and put a new 95-96 cap/rotor on it (the cap/rotor replacments are decent quality) vs any other optispark.
Last edited by dizwiz24; Jun 2, 2016 at 10:15 PM.
Thread Starter
Intermediate
Joined: Apr 2013
Posts: 45
Likes: 8
OK Folks, I'm back. I bought a reman Delco Opti and installed it. Good news is that the bearing in the water pump was failing so I replaced it as well. I don't need to tell you all what a SOB it was doing this repair where you can NOT get access and so forth. I took the old Opti apart and it was full of corrosion so it was in fact a bad Opti. I put the car back together and drove it a couple of miles and it was like new with NO ENGINE LIGHT...Yea.
Now the bad news. I took it for a ride to enjoy my now fixed convertible but three miles down the road it started to loose power. Low RPM acceleration is labored and as the engine increased speed it was improved but I did not think I would make it home. I checked the codes and it shows 12 which is "normal no problems" and I do NOT have a check engine light. It idles fine and it never died but throttle response is about 20%. It seems like it will drop dead but does not and as speed increases so does the throttle response. NOW WHAT? New: coil, wires, plugs, opti, wire harness from the opti, water pump, HELP
Now the bad news. I took it for a ride to enjoy my now fixed convertible but three miles down the road it started to loose power. Low RPM acceleration is labored and as the engine increased speed it was improved but I did not think I would make it home. I checked the codes and it shows 12 which is "normal no problems" and I do NOT have a check engine light. It idles fine and it never died but throttle response is about 20%. It seems like it will drop dead but does not and as speed increases so does the throttle response. NOW WHAT? New: coil, wires, plugs, opti, wire harness from the opti, water pump, HELP
