80LS1T Posted April 3, 2009 Share Posted April 3, 2009 Well I replaced my first optispark when I rebuilt the engine way back in like 03'....since then I have only put maybe 5000 miles on the car. Last spring I found that water had gotten past the connector on top of the opti and corroded the inside of the whole darn thing(found this after I chopped it up!). So now with maybe 1000 miles on this opti its junk again! The engine keeps stalling at random at idle and misfires once and a while in the upper RPM range. It's also throwing a DTC 16 for the low res signal from the opti. I have checked the wiring and its all good to and from the ECM. So I called summit racing where I got my AC Delco Opti(OEM) and talked to them. They said GM performance parts are not usually covered. The guy on the phone also asked me if I checked the rotor......I'm like um no this is not a typical distributor, its for an LT1.......then he goes "ohhhh" in a voice of disgust LOL! He talked to his boss and they said they would cover it for me and to just send back the old one! God I was soooooooooo happy not to have to drop another $310 on another opti! I swear to god if this one takes a crap in a year this motor is coming out and getting replace with something bigger and better! Guy Quote Link to comment Share on other sites More sharing options...
MoNkEyT88 Posted April 3, 2009 Share Posted April 3, 2009 Wow, that sucks. Does MSD make anything for the LT1 application? Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 3, 2009 Author Share Posted April 3, 2009 Yeah they do but it doesn't sound like they are any better. The MSD unit can adjust timing aparently but I wouldn't use that feature anyway since I change my timing through the ECM. Quote Link to comment Share on other sites More sharing options...
gvincent Posted April 3, 2009 Share Posted April 3, 2009 Wow you have had bad luck with your Opti. I have zero miles on my replacement motor in the Z right now as it is still going back together and I swapped the original Opti on this motor even though it had only 80K on it when I pulled if from a good running Caddy. My sons Formula has close to 90K on the original with just a new cap and rotor 3K miles ago, still running strong, Friend has a Caddy with 175K on the original Opti, I thought all the problems were with the 93-94 non vented. My original motor was a 95 Trans Am with 85K and original Opti, I put a MSD cap and rotor on it but it spun a rod bearing while still on Jack stands so really zero miles there. I think we both need a new run of luck, if this LT1 throws a bearing I am going back to old school with a 406SBC! Quote Link to comment Share on other sites More sharing options...
jack46 Posted April 3, 2009 Share Posted April 3, 2009 Condolences. I thought it was boost that made my optis fail, I struggle with the Opti and wish there was a ‘cure’. I do seal the opti cap with RTV to avoid water in it, but that seems to help very little… Well at least they covered the replacement for you. The cost is not that important to me as much as the time to replace, down time and the lack of feeling secure with an opti. Quote Link to comment Share on other sites More sharing options...
jack46 Posted April 3, 2009 Share Posted April 3, 2009 Wow you have had bad luck with your Opti.I have zero miles on my replacement motor in the Z right now as it is still going back together and I swapped the original Opti on this motor even though it had only 80K on it when I pulled if from a good running Caddy. My sons Formula has close to 90K on the original with just a new cap and rotor 3K miles ago, still running strong, Friend has a Caddy with 175K on the original Opti, I thought all the problems were with the 93-94 non vented. My original motor was a 95 Trans Am with 85K and original Opti, I put a MSD cap and rotor on it but it spun a rod bearing while still on Jack stands so really zero miles there. I think we both need a new run of luck, if this LT1 throws a bearing I am going back to old school with a 406SBC! It seems like the adage if you have a good one it lasts a long time is true. But once they are rebuilt they just don't seem to be worth spit... Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 6, 2009 Author Share Posted April 6, 2009 Ok I got the "old" opti off today and sent it back to summit racing. When I got it off I spun it and found that it was binding and making a lot of noise from the insided. I didn't take it apart but I'm pretty sure the rotor came loose inside. WOW what a piece of junk! Can't want to get another to see how long this one lasts.... Guy Quote Link to comment Share on other sites More sharing options...
jack46 Posted April 7, 2009 Share Posted April 7, 2009 Did you install the rotor on the opti or was it already on the unit? I use locktite on the rotor and never had one come off. I do always worry that the rotor will fall apart or off, but I use MSD rotors and caps and I have never heard of an MSD falling apart... Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 7, 2009 Author Share Posted April 7, 2009 I didnt do anything to the whole opti except install it last time. It was a brand new AC Delco unit. I should be getting my new one on Thursday so burnout and donuts should be happening this weekend! HAHAHA! Quote Link to comment Share on other sites More sharing options...
rsicard Posted April 7, 2009 Share Posted April 7, 2009 80LT1: If you have to replace the Opti again, use the MSD unit. Put one of these in my 1994 Buick Roadmaster that has a LT1 and the quality if MUCH better than GM. Quote Link to comment Share on other sites More sharing options...
Bartman Posted April 7, 2009 Share Posted April 7, 2009 Guy, Sorry to hear about your Opti issues, and I hope your back on the street soon. 80LT1: If you have to replace the Opti again, use the MSD unit. Put one of these in my 1994 Buick Roadmaster that has a LT1 and the quality if MUCH better than GM.So what data do you have to substantiate that the MSD unit is any better than the genuine GM unit? I searched before buying mine and couldn't find anything that indicates the MSD unit is any better than the genuine GM Opti. Quote Link to comment Share on other sites More sharing options...
jack46 Posted April 8, 2009 Share Posted April 8, 2009 I hoped the MSD opti would be better it seems like an improved design...BUT from what I read it doesn't last any longer than stock... Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 8, 2009 Author Share Posted April 8, 2009 I hoped the MSD opti would be better it seems like an improved design...BUT from what I read it doesn't last any longer than stock... Yeah and its $200+ more! The guy at summit racing tried to upsell me on the MSD one but I passed. I'll take the free one and go from there! UPS tracking shows it will be here tomorrow so hopefully I'll be back in business tomorrow night! Guy Quote Link to comment Share on other sites More sharing options...
jack46 Posted April 8, 2009 Share Posted April 8, 2009 Yeah and its $200+ more! The guy at summit racing tried to upsell me on the MSD one but I passed. I'll take the free one and go from there! UPS tracking shows it will be here tomorrow so hopefully I'll be back in business tomorrow night! Guy If the MSD was guaranteed to fix it I would GLADLY pay the extra $200! BUT from what I have read many have problems with the MSD, many have good luck but seems to be the case for all optis. A good one works a long time. In my latest setup I have a one way valve and when on vacuum I just have a vacuum leak. This way I will maximize the air flow through the unit and hope...with boost and an MSD box I need to vent the cap more agreesively so I am hoping this will work. The trims at idle are off, but I tuned around it so it seems ok Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted April 9, 2009 Share Posted April 9, 2009 I'd seriously think about switching to MegaSquirt and running a toothed wheel setup. I am trying to decide whether I want to base my '75 on an LT1 (reverse cooling flow is good for turbo's), or going with an LSx based engine. Either way it will be MS - that is what I'm using on my '83ZXT.... Quote Link to comment Share on other sites More sharing options...
slown280z Posted April 9, 2009 Share Posted April 9, 2009 ^^You don't even have to do that, you can get MicroJolt (I think that's what it's called), it's an ignition controller built around the megasquirt hardware, but it's way smaller. Then you can run EDIS-8 and get rid of the damn opti! Quote Link to comment Share on other sites More sharing options...
rsicard Posted April 9, 2009 Share Posted April 9, 2009 Bartman: I ordered a MSD opti spark distributor from Summit Racing and got the wrong one. Took it apart and the GM distributor and visually compared the two. The optical wheel was MUCH better secured on the MSD unit. The GM unit looked WEAK in this aspect. The MSD unit included an mechanical adjustable pickup and the cap and rotor were MUCH sturdier according to visual inspection. The 1994 Roadmaster still get 24 MPG on road trips. Quote Link to comment Share on other sites More sharing options...
MikeJTR Posted April 9, 2009 Share Posted April 9, 2009 The opti spark fails for a number of reasons. One of the reasons the opti-spark can fail is because of improper venting. The earliest LT1 Corvettes were recalled because a vent hole was mistakenly sealed. Later LT1's ran a hose from the crankcase ventilation system to suck air through the opti-spark. If you don't have the hoses hooked up, this can cause problems. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 9, 2009 Author Share Posted April 9, 2009 Ya i have the "updated" version. I got it all buttoned up last night and she runs great now! I'm so happy summit covered this one! Time to get out and do some burn outs! Guy Quote Link to comment Share on other sites More sharing options...
MoNkEyT88 Posted April 9, 2009 Share Posted April 9, 2009 lets race. although I maybe pulling the motor out to install a light flywheel and fix some exhaust leak issues. And wiring.. fab up a new brace.. yeah, lets not race. Quote Link to comment Share on other sites More sharing options...
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