Help with optispark

[F.G.]

Hi everyone, I am in need of my LTX family's help. I am in the middle of an engine build and have been trying to find a good opti to use. I have been looking for AC delco and delphi units but can't seem to find any. Delphi seems to be discontinued and A.C. delco only has remanufactured units. I've also read that dynaspark wasn't good for a few years. Any updates on their quality? I was also looking into a 24x conversion but not only is it very expensive but the gauges and traction control malfunction on 92 and 93 vettes when using this system. I have contacted torqhead and they don't have anything for 92 and 93 vettes either. I am at a complete loss right now and really need to find a solution because the car is at a shop and the build is moving quickly. If anyone has any suggestions on a good aftermarket unit or a lead on ac delco or delphi optis please let me know. Also if anyone has a good opti they want to get rid of please let me know. Thank you all.

[BALLSS]

If I needed to buy a new opti today I would get the AC Delco reman

rockauto.com has them for $345 + $30 core

http://www.rockauto.com/en/moreinfo.php?pk=2781866&cc=1041310&jsn=444

the $1xx ones are cheap...but hit and miss if they work

[F.G.]

If I needed to buy a new opti today I would get the AC Delco reman

rockauto.com has them for $345 + $30 core

http://www.rockauto.com/en/moreinfo.php?pk=2781866&cc=1041310&jsn=444

the $1xx ones are cheap...but hit and miss if they work

That's what I was thinking. Maybe get the reman one and put an msd cap and rotor on for the vent. Hopefully it lasts until torqhead comes up with a solution for my year of car. According to the person I talked to they are hoping to have something available by late summer

[ElkySS]

I've been running an MSD opti for 7ish years. The rotor screws backed out once but that's the only issue it's ever had. But that can happen to any opti.

[F.G.]

Thank you, I've been thinking about an MSD opti as well. Decisions decisions

[popo8]

If I needed to buy a new opti today I would get the AC Delco reman

rockauto.com has them for $345 + $30 core

http://www.rockauto.com/en/moreinfo.php?pk=2781866&cc=1041310&jsn=444

the $1xx ones are cheap...but hit and miss if they workThats all i use on all my lt1s. I was buying them from American-Powerhouse until she stopped carrying them, but bothing wrong with the remaned ones.

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[popo8]

That's what I was thinking. Maybe get the reman one and put an msd cap and rotor on for the vent. Hopefully it lasts until torqhead comes up with a solution for my year of car. According to the person I talked to they are hoping to have something available by late summerI wpuldnt even swap out the cap. Ive run vented amd unvented delco remaned optis with no issues. In fact they are nicely sealed from the factory with nice weather pack ends on the harness as well.

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[popo8]

Thank you, I've been thinking about an MSD opti as well. Decisions decisionsIm gonna be a nay sayer amd say dont do it. Had a billet msd opti that was the issue for a high rpm misfire... had msd rebuild it amd sold it upon return... then my ta came with a billet msd opti amd within a few weeks of having it... it was a no start... Tubby Z28 i believe also had msd negative memories.

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[Injuneer]

MSD Opti’s built over the past two years or so have had problems with erratic signals from the optical cam position sensor. There’s a thread on here hilighting this problem and its symptoms. MSD claims they found the fix, but there's no evidence yet to support that. When the problem was prevalent, people were returning units to MSD for rebuild, and the rebuilds were having the same problem right out of the box.

At this point, it’s a matter of statistics - which one seems to have the lower failure rate. Based on tracking the problems on sites like this for 20 years, the AC Delco reman is not perfect, but it appears to be the best available. I would recommend the vented cap. The vent was added by GM to remove the ozone generated by the internal high voltage sparking. Ozone is highly corrosive, and accounts for the rust particles that can blind the optical emitter/receptor.

[fullforce]

Ive had my opti on for a year now from summit with no issues

[SSlowBoat]

STAY FAR AWAY FROM MSD. i sent them a perfectly functioning opti for a refresh due to age/mileage. they charged me $150 for cap and bearings and sent me back an opti that didnt work. it would start idling erratically, revving on its own, etc. sent it back again and they sent me a new opti. guess what, same thing. i ended up reusing an old stock opti full of antifreeze/oil and 180k miles and did dyno day with no issues.

currently im running a $79 dollar amazon opti with a msd vented cap/rotor, no issues thus far

[F.G.]

Thank you all for the good advice. I'll definitely stay away from msd. It looks like the ac delco reman is my best bet.

Has anyone used petris optisarks. They claim to have a Mitsubishi grade optical sensor and convert non vented units to vented via the cap. Heard a few good things about them but unfortunately not a lot of people seem to be running them yet.

[popo8]

Thank you all for the good advice. I'll definitely stay away from msd. It looks like the ac delco reman is my best bet.

Has anyone used petris optisarks. They claim to have a Mitsubishi grade optical sensor and convert non vented units to vented via the cap. Heard a few good things about them but unfortunately not a lot of people seem to be running them yet.Never heard of them...

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[Injuneer]

Petris has been selling an Opti for many years. Initially, it was just a GM Opti with their vent system (some tubing and a tee fitting in the three vent holes) on the base of the unvented base unit. Appears now they assemble their own units, with an optical module they claim is "a MITSUBISHI-GRADE OPTICAL SENSOR MODULE" (their caps, not mine).

http://petrisenterprises.com/optispark-distributor/

This unit appears to be more popular with the Corvette folks. Petris is a Corvette specialist shop, and does a lot in terms in providing tech help to the community. I have only seen one or two people on F-Body sites even mention Petris, have seen no feedback on the quality of the units. There was a big blowup on one of the Corvette boards by a guy that claimed his Petris was faulty right out of the box, causing DTC 16, and that the replacement Petris sent did the exact same thing, producing DTC 16 and no start. He then claimed he bought a Chinese cheapie and the DTC problem went away. Petris was on the site and got extremely defensive, claiming he had NEVER had a problem with one of his distributors. It turned into a pi$$ing contest, with a lot of he said-she said back and forth, threats of legal action etc. It got so bad that the site just closed the thread and told them to take it offline, so I never saw and outcome.

[Brandon++S]

Yes Petris is definitely geared more toward Corvettes but seems to know there stuff.

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[F.G.]

I think I've settled on an ac delco reman. I have a long story about this car and the build that I will write about on my build thread.soon.

[Injuneer]

Apparently the early Corvettes had a 5-wire Opti harness, not the 4-wire like F-Body and B-Body. The extra wire was intended as a shield wire to minimize high frequency interference, possibly because of the Corvette non-metallic body. Eventually the Corvette changed from 5-wire to 4-wire at some point, but I don’t know when.

[F.G.]

I didn't know about that either. Does that mean the connector on the opti itself is different than F-bodies?

[Fastbird]

Petris has been selling an Opti for many years. Initially, it was just a GM Opti with their vent system (some tubing and a tee fitting in the three vent holes) on the base of the unvented base unit. Appears now they assemble their own units, with an optical module they claim is "a MITSUBISHI-GRADE OPTICAL SENSOR MODULE" (their caps, not mine).

http://petrisenterprises.com/optispark-distributor/

This unit appears to be more popular with the Corvette folks. Petris is a Corvette specialist shop, and does a lot in terms in providing tech help to the community. I have only seen one or two people on F-Body sites even mention Petris, have seen no feedback on the quality of the units. There was a big blowup on one of the Corvette boards by a guy that claimed his Petris was faulty right out of the box, causing DTC 16, and that the replacement Petris sent did the exact same thing, producing DTC 16 and no start. He then claimed he bought a Chinese cheapie and the DTC problem went away. Petris was on the site and got extremely defensive, claiming he had NEVER had a problem with one of his distributors. It turned into a pi$$ing contest, with a lot of he said-she said back and forth, threats of legal action etc. It got so bad that the site just closed the thread and told them to take it offline, so I never saw and outcome.

I think you just summed up the Corvette Forum in this one post.

[popo8]

I think I've settled on an ac delco reman. I have a long story about this car and the build that I will write about on my build thread.soon.Good call brotha.

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[Injuneer]

I have a Corvette Fuel Injection Manual w/ a GM part #. Has the schematics for all years 82-01. The 92/93 LT1 scematic shows 5 wires from the ECM to the intermediate (called "test") connector. The connector pins are labeled A, B, C, D, F. That would seem to indicate it is a 6-pin connector, with no wire in pin E. The "short" Opti harness from the intermediate connector to the Opti has to connect to that (presumed) 6-pin connector. But the Opti end of the short harness still has the same 4-wire "short" plug connector used on all Corvette and F-Body unvented Opti's.

By comparison, all years of the F-Body (93-97) have a 4-pin intermediate connector, and all 4 pins (A, B, C, D) are filled. I believe I have seen a discussion of how to connect a 4-wire harness to the 6-wire Corvette connector, and they discussed repinning the Corvette harness to a 4-pin connector, or using some sort of adapter. 94-96 schematics show the Corvettes are the same 4-pin as the F-Body.

In the old days, a new Opti didn't come with a harness, you just reused your stock harness to plug into the Opti. But many of the newer Opti's come with the short harness already direct wired to the body of the Opti. It's a newer version that would cause you a problem.

EFI Connection MAY have something to address this.... not sure, looks odd - if it isn't, you might want to contact them and see what they do have:

https://www.eficonnection.com/home/product/optispark-adapter-harness

For reference, this shows an F-Body 4-pin intermediate connector:

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

[F.G.]

^^^ dang brother you're a big help. Tomorrow I'll go to the shop and see if I can use that adapter. I also found an replacement opti harness for the 92 corvette, so i may be able to use that