Started up Ruby for the season. I did not get rank filled before winter. Sputtered when I would get on it. Made it to Shell and put over 16 gallons in and sme ams oil fuel additive in. As long as I didn't step on it, sounded okay. Went 15 miles for ice cream and left for home and it quit. It kept cutting out.
I don't think it is a fuel problem but a electric issue.. Either the battery is getting old or the ICM. I have a replacement ICM and coil. Took the ICM off my spare on the heat sink and thin amount of thermo grease on it. Had a packet of grease I put on. Thinking about putting a bead of rtv around the edge of module to help seal it in.
Getting bots loose on coil bracket and power steering is the problem now with the lower bolt. Wires, plugs and hose's in the way.

Getting to old, can't see what I'm doing.
And now getting to hot to work on it!!!

The battery is probably 8-12 years old even though it started right up when I flipped the shut off on.
Onci get the coil and ICM off, I will be curious of the thermo grease, which I think will be dried out causing the problem.

 

I’d say you’re on the right track. Since you already have the parts, throwing those at it can’t hurt. Especially given the symptoms. It definitely COULD be the ICM and is the place I’d probably start. Hopefully someone who has done the job before can chime in on a way to access the area better.

 

Some wobble extensions make it easy. Also you don’t need to remove the lowest power steering bolt. Just loosen it some and you can get the power steering reservoir/bracket off of the the stud that has to be removed to pull the coil/bracket.

Your problem doesn’t really sound like ICM or coil but of course could be the problem. Did you pull codes or check fuel pressure at the rail?

What did your tach do when it died but the engine was still spinning?

 

I did not pull codes like I normally would. Can't find my code reader and can't see up close to hook up paperclip.
YEs, everytime it sputtered tach would cut out drip to zero.
​zero.Had a similar problem when I first got icar at 76,000 miles. Let it cool and restart would run for a few minutes and quit.
It still could be the battery not holding a charge. I will once I get I started check to see if it runs on the alternator.
I forgot to mention I replaced opti at 107,00 miles with a new Dynaspark I had on hand when I had the issue back in 2008 with the ICM.
Have about 4,000 miles now at 111,000 miles.,
Had spare coil and ICM on hand on the Bracket. I took the ICM off and way back then may have used dielectric grease as it was clear and thin, dried out.
I used most of the little packet of thermo grease on it , tightened to where it just begun to squeeze out. . I use slightly longer screws with double nuts on the m.
I also use a nylon washer between the coil bracket and heatsink so as not to absorb heat from the engine.
You mention the bolts for power steering.
.got top one loose, but can't get lower one. Have a 6 point 9/16 universal impact socket on it and an extension. Was going to use my breaker bar on it with a longer pipe for leverage.. I did get a new right angle cordless right angle 3//8'skobalr impact wrench that will work if space to do so.
I should pull those bolts out and put some never seize on them.
I'll get some picture when I get it off of both.

 

Yeah the bottom bracket bolt I didn’t have much trouble breaking loose, I just ran a long wobble extension through the wires etc and it broke free with a normal ratchet.

As to the heat sink my understanding is the (hot) engine head is actually part of the heat sink… so not sure if using washers to isolate the heat sink itself helps or hurts. Ie is engine temp cooler than what the ICM would get to if not attached. I need to get one of those heat guns to measure!

I saw someone on Camaro forums claiming 20-30 degree less temp by standing off the coil’s bracket from the head. However I question the test. If this was done at idle that is not a proper test…the ICM works harder the higher the RPM. so we’d have to check at say 3k continuous to see what would happen.

Of course these are all educated guesses/hearsay. If I get up the motivation and a laser heat measure gun maybe I’ll check that someday!

 

Got the lower bolt out but had a stud to take out on top bolt behind pump bracket.
Got it and ICM off. ICM slightly tacky. My other one was like that and replaced With new thermo grease. Durlast SL203
This bracket I did not have the nylon washer on.
Will need drill some new holes to move heatsink 1 inch down from coil.

Not sure why I can't post a picture or a video????

 

 

 

This is the old one I had from another engine.

 

Was able to pull codes today. None were noted. Will reinstall coil and ICM. Put new thermo grease on ICM. Used Dura ast SL203. From AutoZone.
WI'll add some dry gas to fuel ad try to start and check fuel pressure. The other thing will be to charge the battery. Can't see the date on it. A Napa legend battery. .
Will replace fuel filter if pressure is lo

1. Bad Fuel, water???
2. Fuel filter
3. Battery

 

Got it back together, but it wouldn't start.
put in another ICM and it started.. tried a third one wouldn't start. Went back to second one that has started but now doesn't!
Hmmm!

 

What is your fuel pressure? Need to confirm what you are missing (spark or fuel)

 

I think that a fuel pressure issue would cause a long start or no start, not intermittent no starts and stumbling. A bad one way valve in the fuel pump can result in no/low pressure which would be a no start or a slow build of pressure which would cause a long start. On a gauge, you’d see it build slowly as it cranks and then drop immediately. A bad pressure regulator would typically bleed off a little slower. Long story short, I don’t think it’s a fuel pressure issue. If you don’t have the equipment, I would have someone test the opti for ground and 12 volt power. If there’s a good ground and power is erratic or nonexistent, something is going on inside the unit, particularly with the optical sensor. Based on the car’s symptoms, it could be the opti and I’d have it tested. This will take all the wondering and throwing parts at it out of the equation. I hate it when the finger is automatically pointed at the opti but it sounds like it could be the problem.

 

Was not able to find anyone to test the ICM. So bought a new one from car quest as a store near me had it in stock
today I got it installed including a new coil.
Engine started and sounded ok.i checked codes, there was none and fuel pressure was 43 psi.
I Took it down the road a short distance and got on it and it started sputtering and dying. When I got it back in the garage still did not have any codes. Started it back up and kept trying to rev it up. Finally service light came on.
Checked codes had 18, 36, and 42.
My opti is a Dynaspark unit I bought in 2008. Did not install it until 2015. I've put less than 13,0000 miles on it. Stored in November 2021. Started a few times but didn't drive it all last year.
Because I thought it might have been a fuel problem even though I had stabilizer in the fuel.
Don't look forward to removing the opti.omorrow
Will call Dynaspark tomorrow.
They are located in Fort Wayne about 120 miles south of me.

Bob Hogan is the name I have for them.
They open early, so hopefully he will give me some things to check that I may have missed????