Dreaded new icm/new coil no spark
#1
Dreaded new icm/new coil no spark
Last week my 93 TA went through pineapple express up here in the PNW. Actually drove it through a large puddle, but the car acted fine immediately after and the next day. 48 hours after the puddle event, It had a hard start and died. Restarts fine so I go get lunch and it dies coasting into a shopping center. I try it a few times with no luck. 2 hours later It starts up after I unplug fuses. Within 3 miles it dies while coasting. Restarts after some fuse play. I make it home. Kill it, then restart it right away for giggles. 24 hours later, same thing no start, but starts after fuse play. I drive it and decide to floor it, down shifts ramps up to 3k rpm pops and dies. Finally restarts and drives fine. Eat lunch. Hard start again after more fuse play, make it home and it hasnt moved or started since, no response to fuse play. Once or twice the tach breifly fluttered erractically the last time it drove. No SES lights, paperclipped no codes either.
What I've done since: installed new master pro ICM (new delco wouldve been a 2 week wait) and my old old working coil. No start. Fuel pump primes every time/fuel shoots straight up from the shrader. Inspect coil wire for spark/ none. Unplugged the closest plug wire, put in a plug and again no spark or arc. Ran out of time to test my ICM.
The car is now garaged and I'll get back to it in 5 days, hopefully it can dry out some if that's the problem. First thing is I'll scour shoebox and start tests when I get back and test my ICM.
Could the swim take this long to kill the opti? I have some side notes of odd behavior the week before her swim that I can share, but these are the main facts.
Ideas?
What I've done since: installed new master pro ICM (new delco wouldve been a 2 week wait) and my old old working coil. No start. Fuel pump primes every time/fuel shoots straight up from the shrader. Inspect coil wire for spark/ none. Unplugged the closest plug wire, put in a plug and again no spark or arc. Ran out of time to test my ICM.
The car is now garaged and I'll get back to it in 5 days, hopefully it can dry out some if that's the problem. First thing is I'll scour shoebox and start tests when I get back and test my ICM.
Could the swim take this long to kill the opti? I have some side notes of odd behavior the week before her swim that I can share, but these are the main facts.
Ideas?
Last edited by Gtpguy; 12-24-2019 at 08:36 PM.
#2
Re: Dreaded new icm/new coil no spark
Run this check:
4th Gen LT1 F-body Tech Articles
Whatever got soaked with water may be starting to corrode.
4th Gen LT1 F-body Tech Articles
Whatever got soaked with water may be starting to corrode.
#3
Re: Dreaded new icm/new coil no spark
Thanks Injuneer. Always a help. I'm away from the car for 5 days now. The day before this all started happening I replaced the dimmer switch in the column. I've been searching and people have been experiencing symptoms like mine related to the ignition switch. Since I was right there before all this happened, and the fact the car drove fine through the puddle and after for 2 days, I might have to get back in there and investigate. What do you think about that as a possibility? Merry Christmas btw.
#4
Re: Dreaded new icm/new coil no spark
Shoebox has a writeup on the ignition switch. The first paragraph describes the symptoms of a bad switch. This is becoming a fairly common problem as the 4th Gens age.
4th Gen F-body Ignition Switch Replacement
Merry Christmas !
4th Gen F-body Ignition Switch Replacement
Merry Christmas !
#5
Re: Dreaded new icm/new coil no spark
Got it installed and still no start. Getting a voltmeter tmw and will try my hand at testing opti and pcm. Do I need a 2nd person or can I leave key on and test?
Last edited by Gtpguy; 12-31-2019 at 07:42 PM.
#8
Re: Dreaded new icm/new coil no spark
Update. I pulled the trigger and removed the opti. Couple questions. Do all GM optis have yellow caps? This one has a black cap and online any new gm cap and rotor is black but every GM opti I've seen has a yellow cap. It looks like it has been taken apart before because whatever sealant they put around it has been rotting off. 2nd question, the bearing doesnt have play but when it spins its not smooth and silent like my spare vented opti I still have. It's more course sounding. I will take it apart later this week when I have time. Been searching online for a new one I might be converting to my vented opti or going with torqhead system. Anyways heres an update
#9
Re: Dreaded new icm/new coil no spark
Took apart the opti and it was filthy. Debated going with TorqHead but I decided having a fully functional time machine once its fully restored would be pretty cool to own. So I decided to clean it out and reseal it. The bearing was rough sounding so I put some grease in it as best as I could. Still I didnt want to be stuck if it didnt work. So I waited and searched every day and finally found a guy selling a working parts lady opti. Once I got it, I opened it up and it had the Mitsubishi sensor. Sweet! Cleaned it and resealed it. I first put the 'black' opti on and it didnt start. Quickly removed it and threw on the parts lady opti. It started. 6 weeks down and it sounded so good to hear it fire up. I'm going to pull apart the black opti and frame the dissected pieces. Should be pretty cool to hang up in the garage.
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