Protection Posted December 22, 2012 Report Share Posted December 22, 2012 My car (97z28) runs fine, then u turn the key off and try to crank it back up and it gets no spark. I've replaced the icm and coil. No refire during the cool down period.. Fuel pressure is fine. The body to engine grounds look bad. I'll prob go out in the morning and it'll fire right up.. I'm lost. I haven't tried the opti or crank sensor. No codes pop up Quote Link to comment Share on other sites More sharing options...
DTM Brian Posted December 22, 2012 Report Share Posted December 22, 2012 My guess is the Opti. Quote Link to comment Share on other sites More sharing options...
Geeesammy Posted December 22, 2012 Report Share Posted December 22, 2012 Optiturd Quote Link to comment Share on other sites More sharing options...
Buckeye1647545503 Posted December 22, 2012 Report Share Posted December 22, 2012 Opticrap Quote Link to comment Share on other sites More sharing options...
Patterson Posted December 22, 2012 Report Share Posted December 22, 2012 Water Pump is leaking on the Optispark. Quote Link to comment Share on other sites More sharing options...
DTM Brian Posted December 22, 2012 Report Share Posted December 22, 2012 Remove LT1 - Install LS1 Quote Link to comment Share on other sites More sharing options...
Mr. Jones Posted December 22, 2012 Report Share Posted December 22, 2012 Remove LT1 - Install LS1 100% best solution. Quote Link to comment Share on other sites More sharing options...
Protection Posted December 22, 2012 Author Report Share Posted December 22, 2012 Sounds like a plan on that ls1! Quote Link to comment Share on other sites More sharing options...
Geeesammy Posted December 22, 2012 Report Share Posted December 22, 2012 5.3 Swapping would forever solve the issue of Opti....and have more HP :gabe: Quote Link to comment Share on other sites More sharing options...
Patterson Posted December 22, 2012 Report Share Posted December 22, 2012 Honestly swapping in a different motor is a bit overkill. Get a new distributor get a few other parts while you are in there and problem solved. I've said it before and I'll say it again the LT series isn't all that bad. That being said LS motors are not without their issues either. Did someone say janky Oil Pump? Quote Link to comment Share on other sites More sharing options...
Cordell Posted December 22, 2012 Report Share Posted December 22, 2012 Honestly swapping in a different motor is a bit overkill. Get a new distributor get a few other parts while you are in there and problem solved. I've said it before and I'll say it again the LT series isn't all that bad. That being said LS motors are not without their issues either. Did someone say janky Oil Pump? Really? That is not a common issue, usually oil pump failure is a byproduct of misinstallation. Quote Link to comment Share on other sites More sharing options...
Geeesammy Posted December 22, 2012 Report Share Posted December 22, 2012 It is overkill, but never hurts to consider :lolguy: Quote Link to comment Share on other sites More sharing options...
Richard Cranium Posted December 22, 2012 Report Share Posted December 22, 2012 Swapping the Opti is not the easiest thing to do, but it really isn't that bad with the right tools. There are hundreds of write ups on the internet on how to replace it. The big thing is to get a quality part since replacing it again would really suck. I don't have any ideas for you on troubleshooting it. If you see bad grounds though, I would fix those. Like you said, the CPS and the Opti are the only parts still there. I would try a crank position sensor first though. The problem you are describing was exactly the same problem I had with a different car and turned out to be the CPS. It threw a code 1 time out of 100 attempts to restart. While you are tearing stuff apart though a tuneup and swap the water pump might be in order if they are original parts. They will fail eventually. Quote Link to comment Share on other sites More sharing options...
Geeesammy Posted December 22, 2012 Report Share Posted December 22, 2012 The big thing is to get a quality part since replacing it again would really suck. I know I read somewhere when I was really into the LS/LT game that someone made a vented Opti. I believe it was MSD. I've heard the Opti's like to get condensation in them, whether it be from a slight leak on the WP or wherever, and that's when the issues start obviously. Not sure if it's made anymore if it ever even was, but just figured I'd throw it out there for food for thought. Quote Link to comment Share on other sites More sharing options...
Patterson Posted December 22, 2012 Report Share Posted December 22, 2012 Really? That is not a common issue, usually oil pump failure is a byproduct of misinstallation. LS1's and 2's. you betcha. Quote Link to comment Share on other sites More sharing options...
Protection Posted December 23, 2012 Author Report Share Posted December 23, 2012 Can you just snap the icm on the pigtail connector or do you have to mount it to that metal bracket for a ground? When I bought the new icm I just unplugged the old one and plugged the new module in after it kicked itself off. When I switched them, still no fire. Quote Link to comment Share on other sites More sharing options...
Richard Cranium Posted December 23, 2012 Report Share Posted December 23, 2012 GM changed from the unvented to the vented style optispark I think in 95. So the 97 would absolutely need a vented style replacement. MSD does make a billet optispark that seems like it would be the best think on earth, but a lot of us LT1 owners think they are junk. I have one on the Camaro, but if it dies I'm going to replace it with an OEM unit. The first MSD only lasted about a year, then crapped out on me 2 days before a track rental. The second seems to be holding up. The ICM mounting bracket I think is just that, a mounting bracket. I don't remember any metal showing around the mounting holes where the bolts might make metal to metal contact for a ground. I do remember some ground wires on the harness right there running to the ICM bracket for a ground though. One simple upgrade is to put a couple washers behind the ICM bracket so that it stands out from the head just a little and keeps some of the heat from the head from cooking the ICM. Just a slight bit of airflow behind the ICM should make a big difference in heat transfer. A REALLY good source of information is Shoe box's website. http://shbox.com/1/4th_gen_tech1.html Quote Link to comment Share on other sites More sharing options...
Protection Posted December 23, 2012 Author Report Share Posted December 23, 2012 Thanks, Rick. I just did the washer mod yesterday and re ran new ground wires. Quote Link to comment Share on other sites More sharing options...
Protection Posted December 27, 2012 Author Report Share Posted December 27, 2012 I'm going to send it to my local shop. Runs for about ten mins, just dies like u turn the key off.. 3-6 hours later will fire back up like nothing is wrong.. Quote Link to comment Share on other sites More sharing options...
Protection Posted December 28, 2012 Author Report Share Posted December 28, 2012 Changed my mind. I'm going to do the opti swap. Should I just replace the cap and rotor or the whole thing? Funds are somewhat limited. Quote Link to comment Share on other sites More sharing options...
Cordell Posted December 28, 2012 Report Share Posted December 28, 2012 Changed my mind. I'm going to do the opti swap. Should I just replace the cap and rotor or the whole thing? Funds are somewhat limited. The whole thing, the opti's pickup is in the distributor not the cap and rotor. Quote Link to comment Share on other sites More sharing options...
Richard Cranium Posted December 28, 2012 Report Share Posted December 28, 2012 If you can afford it I would replace the whole thing with an OEM unit. If you can't then an OEM cap and rotor would be my second choice. It won't be cheap either way. Easiest and biggest mistake you can make is to forget the little water pump drive shaft when you put everything back together. There is a spline drive shaft coming out of the block for the water pump. There is a matching spline drive shaft coming out the back of the pump. Between them needs to be a short metal sleeve with reverse splines to connect them. If you forget that the water pump will not turn and you'll have to pull it back off to correct the problem. You will need a puller to get the crank pulley off the hub adapter. I think I used a medium sized 3 jaw the last time I had mine off. When you put it back on I think the bolts are long enough to pull it back on. Just get each one started and turn each one a little at a time to get it back on straight. Leave the hub adapter on the crank, that one is a pain in the ass to deal with. 3 bolts out and use the puller to get the pulley off. It's press fit, but not awful. If you're getting frustrated remember you have an F-body. If it was a vette there would be a frame cross brace 2 inches in front of the pulley and you would be hammering on the pulley to get it off instead of using a puller. If you do the cap and rotor you will need a funky little reverse torx head screwdriver to get the 4 tiny little bolts out that hold the cap to the body. With my Impala we broke at least 2 of them off. They have been in there a long time and may seized. In fact I think GM might have lock-tighted them in place. If you do you can drill them out and I used some long screws and nylon locking nuts from the hobby shop. If you have headers or are thinking about it for the future, this would be a good time to switch to over the valve cover plug wires. The stock routing location behind the exhaust manifolds sucks to replace the wires. Make sure to secure them tightly otherwise you'll have to replace wires again when they make contact with the manifold and burn through. Message me if anything comes up, I'll see what I can dig out to help. Make sure to read the writeup on shbox.com He has nothing but great information on that site. The job sucks, but is very doable. Quote Link to comment Share on other sites More sharing options...
Protection Posted December 28, 2012 Author Report Share Posted December 28, 2012 I also noticed I have an slp intake, the vacuum tube that goes from the opti to the port on the intake is NOT hooked up and is hanging. The rubber hose was about 8" too short and looked like it broke. I'm going to extend that vacuum and see if it makes it run longer Quote Link to comment Share on other sites More sharing options...
Richard Cranium Posted December 29, 2012 Report Share Posted December 29, 2012 That could be a pretty decent vacuum leak, but I wouldn't think it would be enough to stall a running engine. There should be 2 tubes for the Opti, one that runs to the intake manifold, and one that runs to a port on the intake tube somewhere. Quote Link to comment Share on other sites More sharing options...
Archie Posted December 29, 2012 Report Share Posted December 29, 2012 That LT1 is a beast just replace that pile-of-shit opti, see if you can buy them in bulk Quote Link to comment Share on other sites More sharing options...
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