Dead Opti?
Le Mans Master
Joined: Aug 2015
Posts: 6,086
Likes: 1,972
From: St. Charles MO
DAMN IT, it's not fixed. And I have no idea what's wrong with it. I tried to go racing with it last night. No issues driving to the track. Comes my turn to make my time trial laps, and as I'm coming around the track to take the green flag, going into turn 3, my engine just died (again). Seems that anytime I actually turn high RPMs (5k or more), I lose fire. Car won't restart by letting out the clutch either, but it will restart with the key. It did it 3 times on the way home last night and it's still not throwing any trouble codes (SYS needs to be linking for it have a trouble code correct?)
Racer
Joined: Jul 2017
Posts: 422
Likes: 53
From: PA
I don't know too much about the VATs but could a contact / resistor issue in the key shut the car off with key in the ignition & running? If so try another key? Most of the ignition components would give you some warning, missing & and maybe throwing a code before just shutting the car off, with the exception of the ICM which when it dies it's dead, no intermittent on-off.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
I don't know too much about the VATs but could a contact / resistor issue in the key shut the car off with key in the ignition & running? If so try another key? Most of the ignition components would give you some warning, missing & and maybe throwing a code before just shutting the car off, with the exception of the ICM which when it dies it's dead, no intermittent on-off.
It's more likely to be a loose connection or ignition switch (the switch down the column -not where the key goes), like Matthew said.
1stVette, did you happen to notice what the tach was doing when your engine cut out, but you were rolling in gear...or trying to roll start it?
Last edited by Tom400CFI; May 10, 2018 at 04:22 PM.
Thread Starter
Pro
Joined: Sep 2014
Posts: 588
Likes: 35
From: Smithfield VA
I don't believe that VATS will shut the car off. I believe it only prevents it from cranking. Either way, VATS never cuts spark, so if the car dies while running and doesn't have spark, it's not b/c of VATS.
It's more likely to be a loose connection or ignition switch (the switch down the column -not where the key goes), like Matthew said.
1stVette, did you happen to notice what the tach was doing when your engine cut out, but you were rolling in gear...or trying to roll start it?
It's more likely to be a loose connection or ignition switch (the switch down the column -not where the key goes), like Matthew said.
1stVette, did you happen to notice what the tach was doing when your engine cut out, but you were rolling in gear...or trying to roll start it?
Yes Tom, I did notice. Tach drops to 0 rpms when it stalls out with car in gear (usually in 3rd, but it did stall once in 2nd Wednesday night) and clutch pedal not pressed. If I press the clutch and then let it back out, this is when it backfires and blows a black smoke cloud. If I push the clutch in and turn the key, the car starts with no issue. At least it has every time so far, except when the coil fuse (IIRC) blew. I do remember it was in the far right row, 5th fuse down/4th fuse up in the fuse box).
Last edited by 1stVetteFinally; May 11, 2018 at 09:50 PM.
Cruising
Joined: May 2018
Posts: 11
Likes: 0
H16 intermittent no start
The opti, as with other distributors, is a two-segment device. There's a low-voltage segment that senses camshaft position, velocity and acceleration, and feeds that info to the ECM by way of two pulse trains (low-resolution for position, high-resolution for velocity and acceleration). If there's a fault in this part of the unit, there should be at least one DTC stored in memory. The ECM can run the engine, albeit not optimally, without the high-resolution signals, but it will not fire the coil if a low-resolution fault is detected.
And, there's the high-voltage segment, which distributes spark from the coil to the appropriate spark plug via the rotor and cap. A fault on this side of the unit will not directly trigger a DTC.
In most cases, an abrupt shut-down without any misfiring/crossfiring will not be the result of a failure on the high-voltage side. Most high-voltage side failures will lead to misfire/crossfire from the development of moisture and/or carbon tracking within the cap. Occasionally, something more spectacular goes wrong, such as a rotor that breaks apart, etc.
A fault on the sensor side will often lead to an abrupt shutdown without a lot of crossfiring as commonly occurs with a high-voltage side fault, but it should set a DTC.
Check for stored DTCs, verify the presence/absence of spark, and proceed from there before you start shopping for replacement parts. The opti is often presumed, erroneously, to be the source of trouble, when in fact it isn't. Troubleshoot the problem methodically, then take remedial steps as necessary.
Live well,
SJW
And, there's the high-voltage segment, which distributes spark from the coil to the appropriate spark plug via the rotor and cap. A fault on this side of the unit will not directly trigger a DTC.
In most cases, an abrupt shut-down without any misfiring/crossfiring will not be the result of a failure on the high-voltage side. Most high-voltage side failures will lead to misfire/crossfire from the development of moisture and/or carbon tracking within the cap. Occasionally, something more spectacular goes wrong, such as a rotor that breaks apart, etc.
A fault on the sensor side will often lead to an abrupt shutdown without a lot of crossfiring as commonly occurs with a high-voltage side fault, but it should set a DTC.
Check for stored DTCs, verify the presence/absence of spark, and proceed from there before you start shopping for replacement parts. The opti is often presumed, erroneously, to be the source of trouble, when in fact it isn't. Troubleshoot the problem methodically, then take remedial steps as necessary.
Live well,
SJW
It only lost a few ounces of coolant from pinhole. Thanks
Cruising
Joined: May 2018
Posts: 11
Likes: 0
H16
i replaced optispark a few years ago, low miles, and a few weeks ago water pump failed. After pump replacement all is well. Last night sprung pinhole in small hose from tee to h20 pump. Replaced and next time I try to start, it only cranks. Car ran fine and hose repair was just under throttlebody. If I clear H16 code it’s fine. Randomly again a no start. H16 code stored. Could it be in connector to opti and can I get to it without tear down? Mine in supercharged and labor intensive.
It only lost a few ounces of coolant from pinhole. Thanks
cools down and starts and runs fine. Once it warms up and i shut it off, the intermittent no start reoccurs. Only thing that makes sense is getting coolant on connector. Thoughts?
Racer
Joined: Sep 2012
Posts: 491
Likes: 40
From: Mardi Gras City
St. Jude Donor '19
reman opti working, but after spending $2,496.89 at 2 shops to "fix" ignition (plus new water pump} car surges while trying to drive at steady speed. in 13 months of ownership, cost of repairs and PM has averaged $836 per month . my 1/8 share of an east Texas oil well can't keep up with cost of repairs on a chevy. hope this BS ends soon.
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Racer
Joined: Sep 2012
Posts: 491
Likes: 40
From: Mardi Gras City
St. Jude Donor '19
what kills me is that my CE LT4 is no POS $3k barn find, it is a beautiful Barrett-Jackson car. cost of repairs in a year has exceeded purchase price. AND... it is impossible to see where one single cent was spent, car still looks exactly the same.
Melting Slicks
Joined: Nov 2013
Posts: 3,451
Likes: 336
From: Greater Cincinnati Area.
OUCH!!! Owning a Vette is supposed to be fun. Money like that just sucks the fun right out of it.
Ever consider getting a FSM and doing some of the work yourself? It's as rewarding as it is maddening!
Or maybe ask around on the forum for a good shop or a knowledgeable member near you who does this on the side? Lot of them out there.
Ever consider getting a FSM and doing some of the work yourself? It's as rewarding as it is maddening!
Or maybe ask around on the forum for a good shop or a knowledgeable member near you who does this on the side? Lot of them out there.
Cruising
Joined: May 2018
Posts: 11
Likes: 0
H16 optispark
I will check. Wife was working and needed 2nd hand so I’ll recheck. I’m in denial that distributor can fail so easy. When I changed it maybe 5000 miles ago, I put aftermarket that failed in 1000 miles. Changed it out to ac delco o e opti and cap/rotor
why did pouring water pump not affect it and a few ounces of coolant from hose not affect it until after 1-2 hours of run time. Do I have to pull h20 pump back off to get to connector and what are the chances and tests the connector is problem? I think I am probably gonna pull back apart but don’t want to start throwing parts at it. I don’t have any wiring that looks frayed or anything. Cars in good shape for 24 years and 170k. With ProCharger there’s no room. If I do have to pull it back apart I want to be sure and put on the best. Who sells best/most reliable (with vent kit)?
Last edited by Macvipersd; May 27, 2018 at 02:04 PM.
Racer
Joined: Sep 2012
Posts: 491
Likes: 40
From: Mardi Gras City
St. Jude Donor '19
OUCH!!! Owning a Vette is supposed to be fun. Money like that just sucks the fun right out of it.
Ever consider getting a FSM and doing some of the work yourself? It's as rewarding as it is maddening!
Or maybe ask around on the forum for a good shop or a knowledgeable member near you who does this on the side? Lot of them out there.
Ever consider getting a FSM and doing some of the work yourself? It's as rewarding as it is maddening!
Or maybe ask around on the forum for a good shop or a knowledgeable member near you who does this on the side? Lot of them out there.
Cruising
Joined: May 2018
Posts: 11
Likes: 0
H16 hot stall
its long fast crank, setting h16 code. It’ll start now but if I warm it to 180* and turn offend wait 1/2 hour, it won’t start till all the way cooled down.
I will check. Wife was working and needed 2nd hand so I’ll recheck. I’m in denial that distributor can fail so easy. When I changed it maybe 5000 miles ago, I put aftermarket that failed in 1000 miles. Changed it out to ac delco o e opti and cap/rotor
why did pouring water pump not affect it and a few ounces of coolant from hose not affect it until after 1-2 hours of run time. Do I have to pull h20 pump back off to get to connector and what are the chances and tests the connector is problem? I think I am probably gonna pull back apart but don’t want to start throwing parts at it. I don’t have any wiring that looks frayed or anything. Cars in good shape for 24 years and 170k. With ProCharger there’s no room. If I do have to pull it back apart I want to be sure and put on the best. Who sells best/most reliable (with vent kit)?
After cooling 2 hours starts right up, then when warm it dies or if I shut off it won’t restart. How does o e unit go 160k but 2nd oe unit go 10k
crap I don’t wanna do this again nor do I have $ for it right now.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
My OEM one failed in a similar fashion. It would get hot and die... cool and run fine. I proved it here:
Sounds to me like you're going to have to pull the distributor again. You can get the plug off the opti with a hook or pick tool... I doubt that's the problem.
I bet the first dousing is what did it...finally made it's way into the lenses. Take it apart, clean it all out, run kleenex through the lenses, and test it like I did in my vid. I bet it works.
Sounds to me like you're going to have to pull the distributor again. You can get the plug off the opti with a hook or pick tool... I doubt that's the problem.
I bet the first dousing is what did it...finally made it's way into the lenses. Take it apart, clean it all out, run kleenex through the lenses, and test it like I did in my vid. I bet it works.
Burning Brakes
Joined: Sep 2003
Posts: 866
Likes: 22
From: Savannah GA
I was out removing my opti today, doing a 24x swap on the Z.
I had an AIP unit in there. 10 miles on it, and it would run a few minutes and die.
I'm using older EFI connection stuff on my Z. I'll be sending in it's old PCM to order up a torqhead setup for my C4 eventually.
I had an AIP unit in there. 10 miles on it, and it would run a few minutes and die.
I'm using older EFI connection stuff on my Z. I'll be sending in it's old PCM to order up a torqhead setup for my C4 eventually.
Cruising
Joined: May 2018
Posts: 11
Likes: 0
My OEM one failed in a similar fashion. It would get hot and die... cool and run fine. I proved it here:
https://youtu.be/T2rh35e8-qU
Sounds to me like you're going to have to pull the distributor again. You can get the plug off the opti with a hook or pick tool... I doubt that's the problem.
I bet the first dousing is what did it...finally made it's way into the lenses. Take it apart, clean it all out, run kleenex through the lenses, and test it like I did in my vid. I bet it works.
https://youtu.be/T2rh35e8-qU
Sounds to me like you're going to have to pull the distributor again. You can get the plug off the opti with a hook or pick tool... I doubt that's the problem.
I bet the first dousing is what did it...finally made it's way into the lenses. Take it apart, clean it all out, run kleenex through the lenses, and test it like I did in my vid. I bet it works.
ok ok thanks so much. How do I bench test, I’m not getting how connections are made to optispark. As much as I’d like to throw a new one I’m gonna follow you advise and remove, clean and test. Electrical spray cleaner ok for inside?
any test info appreciated. Thanks again
Cruising
Joined: May 2018
Posts: 11
Likes: 0
H16
hoping in can disassemble and epoxy after cleaning?
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
ok pulled it apart, when optispark was replaced, it came w harness shrink wrapped to unit. Apparently either when h20 was reinstalled or when I put new one on recently I must have banged connector with water pump cuz it’s broken/loose/wobbly
hoping in can disassemble and epoxy after cleaning?
To test the opti, simply plug the 4 pin "opti harness" into the distributor, take your coil wire (connected to the coil) and position the opti end of the wire near ground -like I had done in my video. Turn the ignition ON, then spin the distributor...it should throw a good spark(s).