ICM? L98 Not Starting
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 16
Likes: 0
ICM? L98 Not Starting
Hi All,
Based on reading several posts on this forum and others, I believe I have a faulty ICM in my 1985 Vette'. That said, when calling around various parts stores to get quotes, I've been asked "which one" I have because there are two that are available? Can anyone shed some light on this?
Thanks,
Jon
Based on reading several posts on this forum and others, I believe I have a faulty ICM in my 1985 Vette'. That said, when calling around various parts stores to get quotes, I've been asked "which one" I have because there are two that are available? Can anyone shed some light on this?
Thanks,
Jon
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 16
Likes: 0
Took the car out of storage, drove it until it warmed up both on city and highway roads (1st time really driving it since purchasing it in Jan).
Ran very strong, nothing funny in the idle, no discernable surges etc....and on the way home I stalled it (getting used to the 4+3) and it wouldn't start up again...had power (i.e. dash, radio and lights worked) but would not turn on...(not a great explanation, I know, but I think it syncs up with others who have had ICM issues).
As for "which one" - the options seemed to have more to do with function than with grade. The dealership only quoted me one type, GM Part#19179581 - is this the correct part (assuming my ICM is causing the issue)?
Ran very strong, nothing funny in the idle, no discernable surges etc....and on the way home I stalled it (getting used to the 4+3) and it wouldn't start up again...had power (i.e. dash, radio and lights worked) but would not turn on...(not a great explanation, I know, but I think it syncs up with others who have had ICM issues).
As for "which one" - the options seemed to have more to do with function than with grade. The dealership only quoted me one type, GM Part#19179581 - is this the correct part (assuming my ICM is causing the issue)?
Last edited by jonrat; May 2, 2013 at 02:26 PM. Reason: error
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
The ICM only has to do with managing the spark timing and advance.
You are still being vauge...
does the engine turn over with the starter? but it does not fire? does the starter do nothing? When cranking, does the engine turn over easily or struggle?
There is only 1 ICM to a car. Ignition Control Module. Period. Problem here is that YOU know more about the problem than the folks selling these parts these days. C4 tech is long gone and they only now understand what has come about in the last 5 yrs. Sad, but techs and parts guys are plug n play oriented and fairly stupid when it comes to common sense parts/problem diagnosis. Their mentality is swap in a new module.
"Which one?"
"I dunno...the one that does whats not working I guess..."
They MAY be referring to the ESC module...thats mounted by the washer bottle, pass side L-98s. Thats more about an ign sub-system..not the primary ign source like the ICM inside the distributer.
You are still being vauge...
does the engine turn over with the starter? but it does not fire? does the starter do nothing? When cranking, does the engine turn over easily or struggle?
There is only 1 ICM to a car. Ignition Control Module. Period. Problem here is that YOU know more about the problem than the folks selling these parts these days. C4 tech is long gone and they only now understand what has come about in the last 5 yrs. Sad, but techs and parts guys are plug n play oriented and fairly stupid when it comes to common sense parts/problem diagnosis. Their mentality is swap in a new module.
"Which one?"
"I dunno...the one that does whats not working I guess..."
They MAY be referring to the ESC module...thats mounted by the washer bottle, pass side L-98s. Thats more about an ign sub-system..not the primary ign source like the ICM inside the distributer.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 16
Likes: 0
Thanks guys.
Sorry for the ambiguity. When the 'no start' was happening, there was no crank at all. Key would turn, dash lights were on, car just wouldn't start.
Tried it today (sat overnight) and she fired up on the first try without any hesitation.
Cheers,
Jon
Sorry for the ambiguity. When the 'no start' was happening, there was no crank at all. Key would turn, dash lights were on, car just wouldn't start.
Tried it today (sat overnight) and she fired up on the first try without any hesitation.
Cheers,
Jon
Burning Brakes
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line
So u dont have a crank no start.
Do this.
Turn the headlights on and try to start it
If the headlights dont dim at all
Its in the starter curcuit.
Like clutch saftey switch
Starter
Starter sol
Fuseable link by/on the starter
If the headlights dim
Battery
Low battery charge
Loose connection ect
Do this.
Turn the headlights on and try to start it
If the headlights dont dim at all
Its in the starter curcuit.
Like clutch saftey switch
Starter
Starter sol
Fuseable link by/on the starter
If the headlights dim
Battery
Low battery charge
Loose connection ect
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Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 16
Likes: 0
Unfortunately, it did not start up today...makes me think that this could be a case of a bad starter...
At this point I think it may be worth it to have it towed to my mechanic and have him sort it out...just wondering what you folks think could be the problem based on the following video
http://videobam.com/ArQfl
At this point I think it may be worth it to have it towed to my mechanic and have him sort it out...just wondering what you folks think could be the problem based on the following video
http://videobam.com/ArQfl
Burning Brakes
Joined: Mar 2013
Posts: 1,131
Likes: 5
From: Illinois/Wisconsin Line
OK Ill tell you exactly whats wrong because ur pretty smart posting a video. Pretty Smart.
From what happened in the video Its real low on Battery Volts So a Jump should start it right up but it also could be a low voltage symptom due to a loose ground or all ur voltage going to ground through ur starter armature .
Do this turn ur headlights on
Look at them on the wall and try and start the motor
If headlights go dead
Jump it
Before u jump it
Grab each terminal connection with ur hand and try and turn it
If u can They r loose and tighten them
When ur jumping ur battery
turn on the headlights on the brights
and jiggle ur jumper cables until headlights are good and bright so u know u've got a good connection
After u start it up check ur dash to make sure u got at least above 12.9 volts and or u can hear ur alt whistling.
I bet it needs a jump and or battery connections r loose
From what happened in the video Its real low on Battery Volts So a Jump should start it right up but it also could be a low voltage symptom due to a loose ground or all ur voltage going to ground through ur starter armature .
Do this turn ur headlights on
Look at them on the wall and try and start the motor
If headlights go dead
Jump it
Before u jump it
Grab each terminal connection with ur hand and try and turn it
If u can They r loose and tighten them
When ur jumping ur battery
turn on the headlights on the brights
and jiggle ur jumper cables until headlights are good and bright so u know u've got a good connection
After u start it up check ur dash to make sure u got at least above 12.9 volts and or u can hear ur alt whistling.
I bet it needs a jump and or battery connections r loose
Last edited by cudamax; May 4, 2013 at 09:32 PM.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
Just watched the video....
LARGE help !
thats just low voltage..not a big deal.
as stated previously by Cuda...
charge battery. Must have 11.5V to crank easily. IF the dash gauge is showing 11V or more as you turn the key,. and the voltage drops wayyyyyyy down..like below 9..then I'd say the starter is toast OR the cables to the starter. I just replaced a starter that had a cracked solenoid...and sometimes worked...sometimes NOT. Usually NOT when it was raining.
IF the dash gauge shows less than 11V...the battery may be junk and/or the alternater may be junk. See what the gauge shows when the eng is running...that tells you if the alt is producing the 14V after start-up that it must. Normal running charge is 13+. If the car drives with less than 13v on the gauge @2000 rpm the alt is probably junk...
These batterys are the absolute minimum that it takes to start a SBC....they are too small for the car so they wear out quickly if they are not maintained well. A good 5 yr battery only last maybe 2 yrs without a trickle charger staying on it.
LARGE help !
thats just low voltage..not a big deal.
as stated previously by Cuda...
charge battery. Must have 11.5V to crank easily. IF the dash gauge is showing 11V or more as you turn the key,. and the voltage drops wayyyyyyy down..like below 9..then I'd say the starter is toast OR the cables to the starter. I just replaced a starter that had a cracked solenoid...and sometimes worked...sometimes NOT. Usually NOT when it was raining.
IF the dash gauge shows less than 11V...the battery may be junk and/or the alternater may be junk. See what the gauge shows when the eng is running...that tells you if the alt is producing the 14V after start-up that it must. Normal running charge is 13+. If the car drives with less than 13v on the gauge @2000 rpm the alt is probably junk...
These batterys are the absolute minimum that it takes to start a SBC....they are too small for the car so they wear out quickly if they are not maintained well. A good 5 yr battery only last maybe 2 yrs without a trickle charger staying on it.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Unfortunately, it did not start up today...makes me think that this could be a case of a bad starter...
At this point I think it may be worth it to have it towed to my mechanic and have him sort it out...just wondering what you folks think could be the problem based on the following video
http://videobam.com/ArQfl
At this point I think it may be worth it to have it towed to my mechanic and have him sort it out...just wondering what you folks think could be the problem based on the following video
http://videobam.com/ArQfl
4th Gear
Joined: May 2007
Posts: 4
Likes: 0
From: Burdett NY
No Start?
A friend with a 91 just had the same problem. Good power but no starter- turned out the ignition switch was the problem- some of the steering columns had loose bolts that eventually cause problems. Key clues were removing the key and chimes still ringing and the engine would stall sometimes. It happened in a parking lot, bit drove there fine! Chev dealer in Albany, NY fixed it.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The clicking is the classic symptom of bad battery cable connections or a low battery.
The solenoid pulls in but the extra current draw causes a voltage drop and the solenoid drops back out. With the solenoid released the load goes away and the voltage comes back up. The solenoid pulls in... and it goes click...click...click.
The sound is the solenoid engaging and releasing. You'll note that the engine does not crank while this is going on, as the load of the starter is too high and the voltage at the starter is too low.
The solenoid pulls in but the extra current draw causes a voltage drop and the solenoid drops back out. With the solenoid released the load goes away and the voltage comes back up. The solenoid pulls in... and it goes click...click...click.
The sound is the solenoid engaging and releasing. You'll note that the engine does not crank while this is going on, as the load of the starter is too high and the voltage at the starter is too low.
Thread Starter
Heel & Toe
Joined: Jan 2013
Posts: 16
Likes: 0
Thanks all - the vette is stored away from where I live so I can only tinker with it on the weekends...that said, I was able to jump start it this weekend and it drove around just fine..
this weekend I will check out BOTH ends of the battery cable (i've cleaned and secured the cables on the battery-end) and check out the ignition switch as well.
thanks for your help!
this weekend I will check out BOTH ends of the battery cable (i've cleaned and secured the cables on the battery-end) and check out the ignition switch as well.
thanks for your help!
Last edited by jonrat; May 7, 2013 at 08:21 AM. Reason: typo