suspect opti death - please help me verify
06-13-2017, 11:18 PM
#1
suspect opti death - please help me verify Hi guys,
I got a 93 Formula about 1-2 months ago and 3 weeks ago while driving my rpms dipped then came back. Started to head home and it died. Restarted, died. Get past the light, start it up, and dies again. Had to tow it home.
When I got home I did the pin jump and got 16 - OptiSpark low resolution pulse not found, 28 - Transmission range pressure switch fault, 46 - PASS-Key II circuit.
My security light is always on, so I am guessing that is related to 46. But what is going on with my optispark and the transmission range switch?
ANYWAYS, I finally had time to really look at it - 3 weeks later and this is what I tested.
Following the shbox guide: http://shbox.com/1/4th_gen_tech2.html#opti_test
Removing the ICM connector I got 12vdc on terminals A and D. I tested terminal B on AC and got maybe .05 volts while cranking. C shows 0 ohms.
I tested the coil and got 8.22K ohms on all 4 terminals.
As for testing the opti harness I am not sure. I am a little confused by shbox. Am I right that I am supposed to remove the harness from the opti, leave it attached near the top of the motor and test from the opti side of the harness. Or do I remove the harness at the top of the motor, and test the harness while still connected to the top?
So thus far it looks like I confirmed that the ICM AC voltage is a problem..
Anyways after I was done I decided to try firing it up again and shockingly it started okay and idled as it should for about 10 seconds then went back to its usual low rpm idle. Then the CEL kicked on (never did before). I left it run for a minute then died with a lot of stumbling.
I checked the codes again and along with 16. I now have the dreaded 36 (Distributor ignition system (faulty high resolution pulse or extra low resolution pulse detected).
Seems like at this point its definitely the opti and or harness since now I have both 16 and 36.
At this stage is there anything else worth checking? I feel like I can almost certainly say its either of those now since 36 appeared.
I got a 93 Formula about 1-2 months ago and 3 weeks ago while driving my rpms dipped then came back. Started to head home and it died. Restarted, died. Get past the light, start it up, and dies again. Had to tow it home.
When I got home I did the pin jump and got 16 - OptiSpark low resolution pulse not found, 28 - Transmission range pressure switch fault, 46 - PASS-Key II circuit.
My security light is always on, so I am guessing that is related to 46. But what is going on with my optispark and the transmission range switch?
ANYWAYS, I finally had time to really look at it - 3 weeks later and this is what I tested.
Following the shbox guide: http://shbox.com/1/4th_gen_tech2.html#opti_test
Removing the ICM connector I got 12vdc on terminals A and D. I tested terminal B on AC and got maybe .05 volts while cranking. C shows 0 ohms.
I tested the coil and got 8.22K ohms on all 4 terminals.
As for testing the opti harness I am not sure. I am a little confused by shbox. Am I right that I am supposed to remove the harness from the opti, leave it attached near the top of the motor and test from the opti side of the harness. Or do I remove the harness at the top of the motor, and test the harness while still connected to the top?
So thus far it looks like I confirmed that the ICM AC voltage is a problem..
Anyways after I was done I decided to try firing it up again and shockingly it started okay and idled as it should for about 10 seconds then went back to its usual low rpm idle. Then the CEL kicked on (never did before). I left it run for a minute then died with a lot of stumbling.
I checked the codes again and along with 16. I now have the dreaded 36 (Distributor ignition system (faulty high resolution pulse or extra low resolution pulse detected).
Seems like at this point its definitely the opti and or harness since now I have both 16 and 36.
At this stage is there anything else worth checking? I feel like I can almost certainly say its either of those now since 36 appeared.
Last edited by timaishu; 06-13-2017 at 11:59 PM.
06-15-2017, 05:55 PM
#5
seems like the common thread is opti codes....
ICM can test good cold but fail when hot...so better to test it when hot
when a engine stumbles, has intermittent ignition problems sensors on the motor can interpret that as knock or transmission, etc.
Get the car running, likely opti, and clear the codes (disconnect battery for 10 min) see if any of the others return and if so move on to whatever that might be
ICM can test good cold but fail when hot...so better to test it when hot
when a engine stumbles, has intermittent ignition problems sensors on the motor can interpret that as knock or transmission, etc.
Get the car running, likely opti, and clear the codes (disconnect battery for 10 min) see if any of the others return and if so move on to whatever that might be
06-16-2017, 07:51 PM
#6
https://www.facebook.com/groups/LT1Nation/files/
Browse these docs.
Browse these docs.
06-16-2017, 09:23 PM
#7
Pulled the harness and tested it and it was fine! Let the battery stay off for 30 min to clear codes.
Fired it up and it ran okay for 30 seconds then went crazy again. Code 36 this time, 16 hasnt come back yet.
Pretty sure I have ruled out everything but the opti.. And knowing mine is a kragen special, I opted to roll the dice and just buy a replacement off ebay. Found a guy who refurbs them, so we will see.
I dont want to pull the kragen, clean it and maybe make it work and have it die later on. This this opti only had maybe 1k miles on it...
Ill update this once I have my new one in hand and installed!
Fired it up and it ran okay for 30 seconds then went crazy again. Code 36 this time, 16 hasnt come back yet.
Pretty sure I have ruled out everything but the opti.. And knowing mine is a kragen special, I opted to roll the dice and just buy a replacement off ebay. Found a guy who refurbs them, so we will see.
I dont want to pull the kragen, clean it and maybe make it work and have it die later on. This this opti only had maybe 1k miles on it...
Ill update this once I have my new one in hand and installed!
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06-16-2017, 10:12 PM
#8
TECH Veteran
Seems like this pretty much explains where you test:
"At the end of the optispark harness (disconnected from the opti) with the key ON, you should see:"
Your're checking everything you can from as close as you can get to the opti back to the PCM.
If you are replacing a Kragen special opti with an Ebay special opti, I'm not sure what you are gaining. The only real way to tell what an opti is doing is with an oscilloscope.
"At the end of the optispark harness (disconnected from the opti) with the key ON, you should see:"
Your're checking everything you can from as close as you can get to the opti back to the PCM.
If you are replacing a Kragen special opti with an Ebay special opti, I'm not sure what you are gaining. The only real way to tell what an opti is doing is with an oscilloscope.
06-16-2017, 11:03 PM
#9
Seems like this pretty much explains where you test:
"At the end of the optispark harness (disconnected from the opti) with the key ON, you should see:"
Your're checking everything you can from as close as you can get to the opti back to the PCM.
If you are replacing a Kragen special opti with an Ebay special opti, I'm not sure what you are gaining. The only real way to tell what an opti is doing is with an oscilloscope.
"At the end of the optispark harness (disconnected from the opti) with the key ON, you should see:"
Your're checking everything you can from as close as you can get to the opti back to the PCM.
If you are replacing a Kragen special opti with an Ebay special opti, I'm not sure what you are gaining. The only real way to tell what an opti is doing is with an oscilloscope.
The seller used a new body + msd cap + new mitsubishi sensor. I figure I am kinda gambling since I didnt test with an o-scope. But from just reading around and the tests, I feel like my hunch is pretty close..
Hope it all goes well!