Is this a Opti spark problem?
Team Owner
Joined: Oct 2000
Posts: 96,443
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From: Fort Knox, KY
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Racer
Joined: Sep 2007
Posts: 393
Likes: 0
From: Bartonville Illinois
Thanks for the help, i don't think it goes into limp mode, it runs like its out of gas, i can restart it and work the gas, but i will go about 30 or 40 feet then die out again. It will keep doing this until it sits for awhile then it will start and run fine. (i'm guessing until it heats up again)
You can check connections on the ICM and have it tested. You need heatsink grease on the back of it where it mounts on heatsink. If you clean that area up you will have to have new heatsink compound. Its available at Radio Shack. You don't need a whole lot of this stuff. A thin coating will be fine.
By the way are you getting any trouble codes?
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Because it dies completely, it moves my thought from the opti to the ECM.
Definitely not true. The opti can definitely react to heat. Don’t try to figure this out with logic, these are just the bare facts. Run cold good, run hot bad.
The opti has a multitude of different symptoms which can’t be neatly sealed in one tidy box. You need to be real open on this.
Instructor
Joined: Jun 2007
Posts: 101
Likes: 0
From: San Antonio TX
I have a 93 and mine did the same thing.
It was the opti!!
Would start up fine then would die after it warmed up sometimes it would start back up and sometimes I would have to wait for it to cool down.
It was the opti!!
Would start up fine then would die after it warmed up sometimes it would start back up and sometimes I would have to wait for it to cool down.
Racer
Joined: Dec 2007
Posts: 345
Likes: 0
From: Flint Michigan, #2 in unemployment, #3 in Violent crimes
mine is doing the same thing, I changed the ICM and coil, nothing, next is the opti.
I have a friend with a 95 camaro, and he replaced his opti 4 times (keeps puking) about once a year, has same symptoms and I do, when the opti is changed, problem fixed for about a year, then returns.
he is putting in new GM Units, but they still fail. he is going to be putting in an MSD now.
I just picked one up on the forum here to put in mine. hope it solves it.
Thread Starter
Instructor
Joined: Nov 2004
Posts: 159
Likes: 0
From: Chesterfield Twp Mi
Well, i FINALLY got the time to dig into my car and figure out my problem. As most suggested, i started with the ICM and coil before going straight to the Opti. Turns out it's a bad ICM, and go figure nobody stocks it, so it had to be ordered. So i'm hoping this will be the solution.
Part will be in on Wednesday, so i should know one way or another then.
Thanks for all the help
mine is doing the same thing, I changed the ICM and coil, nothing, next is the opti.
I have a friend with a 95 camaro, and he replaced his opti 4 times (keeps puking) about once a year, has same symptoms and I do, when the opti is changed, problem fixed for about a year, then returns.
he is putting in new GM Units, but they still fail. he is going to be putting in an MSD now.
I just picked one up on the forum here to put in mine. hope it solves it.
Part will be in on Wednesday, so i should know one way or another then.
Thanks for all the help
mine is doing the same thing, I changed the ICM and coil, nothing, next is the opti.
I have a friend with a 95 camaro, and he replaced his opti 4 times (keeps puking) about once a year, has same symptoms and I do, when the opti is changed, problem fixed for about a year, then returns.
he is putting in new GM Units, but they still fail. he is going to be putting in an MSD now.
I just picked one up on the forum here to put in mine. hope it solves it.
Instructor
Joined: Dec 2007
Posts: 156
Likes: 0
From: Powhatan Virginia
Icm ???
By your original symptoms I would guess ICM--outside chance ECM--after reading your last post--I would put a fuel pressure gauge on it and drive it to see if you have fuel pressure when problem occurs--although fuel pumps usually just DIE period---I don't recall seeing a opti with your symptoms.
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Advanced
Joined: Dec 2006
Posts: 74
Likes: 0
From: University of Miami FL
I have the same thing except, that it does not die it just like misfires and won't shift to the 3 and 4 gear. Could it be the same ICM ECM or opti problem?
And it does all that misfire after I would put on 5-6 rpm on hot engine.
And it does all that misfire after I would put on 5-6 rpm on hot engine.
Thread Starter
Instructor
Joined: Nov 2004
Posts: 159
Likes: 0
From: Chesterfield Twp Mi
TTT
Well, here's my update. I installed the new ICM and the problem is still there. I checked the codes and im getting a code 36. Any help with a code 36? My repair manual says Code 36, Ignition system circut error or transaxle shift problem. I just replaced the ICM????
Thanks!![/QUOTE]
[QUOTE=QBLU92;1565930453]My 92 starts fine, and runs good for about 10 miles then it starts to miss and sputter, then die. I can restart it but it still misses and sputters. If it sits for a length of time (prob long enough to cool off) it will start and run fine for about 10 miles, then it starts missing again.
Could this be the Opti Spark? That is what the Dealer told me and they want $1500 to replace it and the water pump! Not to sure about the dealers work, and I would hate to do the replace myself and find it's not the opti!!
Thanks!!! :cheers
Well, here's my update. I installed the new ICM and the problem is still there. I checked the codes and im getting a code 36. Any help with a code 36? My repair manual says Code 36, Ignition system circut error or transaxle shift problem. I just replaced the ICM????
Thanks!!
[/QUOTE][QUOTE=QBLU92;1565930453]My 92 starts fine, and runs good for about 10 miles then it starts to miss and sputter, then die. I can restart it but it still misses and sputters. If it sits for a length of time (prob long enough to cool off) it will start and run fine for about 10 miles, then it starts missing again.
Could this be the Opti Spark? That is what the Dealer told me and they want $1500 to replace it and the water pump! Not to sure about the dealers work, and I would hate to do the replace myself and find it's not the opti!!
Thanks!!! :cheers
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
QBLU92,
not sure what 'repair manual' you have, but it doesn't sound like a FSM.
So, in case this will help...
my FSM for our 1994, notes a DTC 36 as follows:
Distributor Ignition System (faulty high resolution pulse or extra low rsolution pulse detected).
DTC 36 will set when: 40 low resolution pulses occur before any high resolution pulses are detected.
Diagnostic Aids: Th engine does not need the high resolution pulse to operate. If a DTC 36 is present and the vehicle will not start, check for DTC16 and use that chart first.
BTW, a DTC 16 is: Low resolution pulse (7200 high resolution pulses before any low resolution pulses).
not sure what 'repair manual' you have, but it doesn't sound like a FSM.
So, in case this will help...
my FSM for our 1994, notes a DTC 36 as follows:
Distributor Ignition System (faulty high resolution pulse or extra low rsolution pulse detected).
DTC 36 will set when: 40 low resolution pulses occur before any high resolution pulses are detected.
Diagnostic Aids: Th engine does not need the high resolution pulse to operate. If a DTC 36 is present and the vehicle will not start, check for DTC16 and use that chart first.
BTW, a DTC 16 is: Low resolution pulse (7200 high resolution pulses before any low resolution pulses).
Le Mans Master
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
Not entirely true the engine will start but not run well. The high res pulse is used for timing the low res for firing. No timing adjustment will occur if the High res pulses are not present.
Advanced
Joined: Nov 2004
Posts: 63
Likes: 0
From: Birmingham Alabama
My car is also running bad when it gets hot. I changed out the coil with a new one and now the car won't fire at all. I checked for spark at one of the cylinder and got nothing. I put the orginal coil back on...nothing. 
There was second while trying both coils where I tought it almost was going to fire. I'm going to have the ICM tested today.
I'm watching to see how this turns out so I can get mine running again.
There was second while trying both coils where I tought it almost was going to fire. I'm going to have the ICM tested today. I'm watching to see how this turns out so I can get mine running again.
1st Gear
Joined: Apr 2013
Posts: 1
Likes: 0
From: Ridgecrest California
Intermittent No Start Issue
HELP! I have a 93 Vette that only starts when it is cool or cold. Once she starts she runs like a charm. I have had the ecm replaced. I have had the bcm AND pcm's rebuilt and it is still doing the same thing. According to my mechanic, the diagnostic points to the bcm. I am at my wits end right now. Can anyone give me some advice on where to go now? Thank you so much
