1995 LT1 Camaro,...it would stop running intermittently, the motor just going DEAD,...might start right up, might not,...could run great for days, then other days I was afraid I would'nt make it home from the gym,...two tows home,...three fuel pumps(it needed at least one of them and I have a nice trap door now?!),...I wanted to just give the f**king thing away,...thought I discovered a loose coil connection,...swapped in a new ICM, tried a different coil,...nothing.
I had installed a new Opti in the motor build and there did't seem to be any consistency to the stalling,...I was leaving that one till the very last repair?!.

failing ignition switch, pulled the steering column as per Shbox's tutorial, an easy job really, swapped in the new switch and *drum roll*SOLVED,...FINALLY.

I'm posting this in case someone else like me is looking for a clue.

very hard to diagnose because the car acts completely normal and then is dead,...then normal,.............

I can change a fuel pump now in the dark with one arm tied behind my back,...it might come in handy?!

 

My heart sank today,...barely made it home from work,...stalled maybe 10-12 times,....sometimes started right up, other times only after a dozen tries on the starter,...one time a couple of minutes spent fuming at the road side,...hands holding the hood full open even tho the struts could hold the hood up,...better that way as I just might pull my f##king hair out.

The 4 way flasher works good.

Loose PCM connection?!,...anything but the Opti?!,...I don't want to pull the front of the motor apart.

5,000 miles on a new Chandler Opti installed on a new 383.

Did I say F**k already?!

Here's a stretch,...the original Opti vent harness hoses near the Opti housing were really soft from oil exposure and easily collapesable under pressure,...is that it,...@#!7!!!?#!!

 

So,...most of the stalling happening on days when I'm driving a lot of short trips in town. A lot of low rpm driving.

Thought I did all the electric testing I could but my retired mechanic Father remided me of "load testing" the battery.

Put a charger on the battery last night and the car is running better(?!).

Could it be the battery is not getting charged sufficiently with all the short trips/low rpm driving and is now failing when the engine compartment is getting heat soaked?,...maybe the PCM is not getting the required juice?.


I'll keep this thread updated.

 

Bad battery can do weird things to a car. I suggest taking it to get tested on the car. That way you can get the battery-starting system-charging system all tested at the same time.

 

Installed a brand new battery yesterday morning, fully charged, the car ran perfect till going home last night.
I was running the car hard thru the gears a couple times and getting a miss/stumble in the mid range?, stopped by a frens place to help with his bike brakes, 30 minutes later go to drive home and it stops running right after it starts, restarts in fits and stops, eventually would not start/run AT ALL,...pulled the PCM fuse/reinstalled, pulled PCM and reset the 4 plugs,....nothing.
Left it there last night.
It's got to be a bad Opti I'm thinking.

Went back this AM to pull the car home and It fired right up instantly and ran great?!.

I have the original GM Opti with 180,000 miles of "road seasoning" sitting on the shelf,...

Here's my question for the day guys,...I havn't checked the opti harness connector at the optispark housing,...is there a way to get at that plug and pull it,...I can barely SEE it in there?.

 

crank sensor going bad is my best guess.

 

They didn't have a Crank Pos Sensor until 96.

 

cap and rotor good?

my buddy just had a similar issue on his 3rd gen and the cap actually had broken... and the rotor button was broke as well... funky ****...

its got that corrector cap style cap right?

 

ha! missed the year.

 

I changed out the Opti vent harness with a brand new one today, also changed the Opti electrical harness.

The car was running great,...till I did a couple short trips on this sunny/warm day,...then same old stuff,...a couple coughs(misses) then complete shut down while driving,...no start,...stranded.

I left hood open for an hour or so, wiggled the temp sensor connectors, checked the coil connector/s,...nothing,...took the trap door off and pounded on the fuel pump a couple times,...nothing,...30 minutes later it cranked back to life like nothing had happened?!,...

I've got the original stock high mile Opti and I guess it's time?!.

I'm beyond frustrated now,...zen like,...this has got to be it,...right?

 

Might be the ICM if it's dying after it heats up.

 

basics, basics, basics.

when it's not starting.....

do you have spark?
do you have injector pulse?
do you have fuel pressure?

 

sub'd to this thread, having identical issue

 

It's got to be heat soaking into the Opti and the module failing due to the heat.

The pattern is obvious now. if I can keep driving and having air flow underhhod then no problem,...but throw in a couple stops/short trips and the ignition starts "dropping out",...check THIS out, just found it while surfing for a solution.

The new Opti-Spark distributor has a limited lifetime warranty. The real enemy of the O.E. Opti-Spark unit is heat. Sandwiching any distributor between the engine block and the water pump just begs for trouble. In the shop we have discovered that several failures typically occur; distributor shaft support bearing being the most common. The lubrication for the small diameter distributor shaft support sealed bearing dries up and then the ball bearings gradually turn to metallic dust. The intense heat from the failed or failing bearings eventually overheats the Opti-Spark module creating the second most common failure. The Opti-Spark modules are tough, but they can only handle the heat for so long before they leave you on the side of the road wondering why the engine just quit.
If you have cleaned your engine and then experienced problems or had a water pump fail you are probably aware of another common failure. GM placed a cooling system bleeder at the water outlet above the distributor. Attempting to open that bleeder valve can leave you walking. The heat attacks the distributor cap and housing seals leaving multiple areas for water intrusion. Our ventilation kit provides clean cool airflow throughout the entire distributor to dissipate the heat.
How do you know the Opti-Spark is failing? Let's say you are out in city traffic. As heat builds under the hood you notice a minor misfire initially, then stalling occurs. At first the engine usually starts right back up, but as time goes by the wait time is longer before the engine will start. After a while the engine will run when it is cool but as soon as heat builds it dies. Then it will not start no matter what the temperature is.
What about coolant leaks? If the water pump or any hose fails and dumps coolant on the Opti-Spark you will probably end up walking. Our ventilated unit will succumb to massive amounts of water but in general a coolant leak would not leave you stranded.
The Opti-Spark itself is challenging to install, but the ventilation retrofit kit installation is easy. Do not be surprised if you find that your water pump bearings have failed (the bearings will be visible when the pump is removed for Opti-Spark replacement).


Exactly whats happening to me, the warmer that Opti gets the less it works.

I've got the original GM opti but it's really high mile, 180,000 miles or so.

I'm thinking about swapping the original GM module into the low mile Chandler Opti ????,...

 

I have a complete set of extra components, swapped all, one at a time other than the Opti with no luck.

 

Hey guys,...how about this?

Quote:
I had a similar problem, car starts fine cold, runs 20 min, until fully warm then dies. Won't restart until fully cooled down. It was the connector to the ICM. When it was cold it would make contact with the pins inside, when warm they moved just enough so there was no spark. I started the motor and began jiggling all the connectors under the hood, when I jiggled the connector to the ICM the motor stumbled, when I moved it again it died. I opened the connector and bent each pin slightly, problem solved. Worth a try, good luck.

 

I had that problem with mine, too, after the opti died and I replaced it. Worth a checkout.

 

Pulled the Chandler Opti off today,...not such an ordeal,...car up on jack stands. With the front wheels hanging in the air there was lots of room to work over the top and under the front end.
Drained the rad,...careful not to spill too much antifreeze,...everything came off pretty easy.

Earlier in the day I had taken apart the Hi mile(180K Miles, worked great) Original GM opti to check it out,...I used a screw off the top of an LT1 throttle body to get the E4 size male torx screws off.
There was a little clean looking oil inside, not enough that it prolly affected the opti. the rotor and cap looked well used, signifiicant signs of arching/wear between the rotor and cap electrodes,...one of the spark plug lead connectors on the cap also looked like it had a lot of arching type corrosion.(loose plug wire connection?),...all in all it looked like it had been working as designed, and it had never let me down.

The original Hi Mile GM waterpump looking mint, no signs of leaking(?!)

I took the 5,000 mile Chandler opti apart,...

first off it was obvious the rubber seal between the outermost cap with the plug terminals and the "middle" plastic cap was absolutely not installed correctly and that water/oil COULD have been totally free to drain right into the opti if it was there anywhere near the top of the opti. The square O-ring was twisted and obviously pinched in between the two housings.

A little clean oil was inside the opti, just like the GM Opti, but again pretty obvious that it was'nt enough to cause problems.

The rotor was on tight and everything looked mechanically perfect.

I swapped the Opti optical sensor modules using a 5/32" socket to loosen/tighten the sensor mounting Torx screws(Could GM not have used standard fasteners on this entire piece ?!).
Cleaned up the inner workings carefully with a microfiber cloth and rubbing alcohol and bolted it all back up.
I used red loctite on all the fasteners and a good silicone sealer at every single seam/O-ring, and then again over every seam on the outer aspects of the opti.
Missed the parts store for new waterpump gaskets so called it a night. Not bad as the silicone will harden up overnight.

So, I'm going with the original GM opti sensor in the Chandler Opti,...all loctited and sealed,...be back tomorrow night with the results.

 

i'm not saying anything about its functionality.....but i've always HATED WITH A PASSION when i had to do those dam things. who was the friggin rocket scientist that put that **** down there like that? it's almost like a ford engineer went to work for gm when they made that stupid ****.

 

Not to mention all the retarded fastener choices. I was extremely pissed off at having to go buy a 3/8" allen socket to swap my brakes, then buying an e4 socket for the opti cap screws, and a t8 for the rotor screws so I could loctite them, and I'm looking forward to finding another obscure socket I need. Fck you, GM.