Need some help with my 96 DCM. My wife went through some deep puddles and failed to tell me. A couple of days later as I'm driving my car backfires once at high RPMs. Didn't think much of it until it started getting more and more frequent to the point where it switches gears at high rpms the car shuts off and it sounds like pop corn. Told the wife about it and she told me that she went through high puddles to the point that the car cut off and she was having a hard time keeping it on and getting it started. I got a new Opti and swapped it out. car seemed to be back to normal, waited until it was at operating temp and I hit the main road and it cut off. I was having a hard time getting it to start. Waited a couple of minutes and it would start and I would drive for about half a mile at 20mph and it would cut off again and so on until I got it back home. The code I got after I got it home was p0372 my guess is that the opti is fried or should I look somewhere else? Two of my guesses are the opti plug and the vaccum harness. I'm going to be off for the next couple of days so any suggestions could help. How do I check the plug and harness and what else should I look for?.
First the 372 code does not cause ANY engine issues of any kind. this is just to inform the PCM that all is good on the engines mechanical position of the crankshaft and the cam shaft.
you change that sensor sh*t can happen just adding more confusion...
installing a new OPTI can be a very stressful repair, reason is these are now china crap , a big problem in this world of LT1 ....
I had this 372 code when I replaced my opti .. bad opti improperly assembled key was not properly set .. confirmed as I installed opti with cap off and the old opti rotor position was off by 1//8 IN ...it was a spectra opti made in china .. returned and used my 21 yr old opti .. sealed the gasket ..
I myself had a bad opti due to seal issues. the cap seal on the 5 year old opti leaked causing spark issues .. then the ICM/coil also had small arcing which added to this problem .. on a dry day all good , on a damp day not good.
before replacing the NEW opti I would replace the ICM/coil assy.. It is a PITA but that is a start. reset codes and see if it works if not , then the NEW opti is bad. also the new opti may come with a connector these must be sealed at the exterior wire input to the connector OR it will leak into the optical sensor component .. also ALL new opti must be pressure tested to determine NO leaks .. I use a small hand pump and a gauge to see if it holds like 5 PSI..
the old OPTI may be good .. cleaning it and if necessary new cap/rotor.. my experience is the rotor bearing does wear out this is due to OZONE created by the normal opti operation and then if the venting harness is not properly venting it will kill the distributor due to the corrosive ozone gas.
explain how the old opti looked ,you check the opti venting harness ??? need vacuum gauge..
do not mess with the crank sensor that is not the problem , my guess the new opti is china crap.
driving in puddles is not good on the LT1 ... some put sealant all over the opti to keep the water out..I do not drive my 96 in bad weather or puddles.
First the 372 code does not cause ANY engine issues of any kind. this is just to inform the PCM that all is good on the engines mechanical position of the crankshaft and the cam shaft.
you change that sensor sh*t can happen just adding more confusion...
installing a new OPTI can be a very stressful repair, reason is these are now china crap , a big problem in this world of LT1 ....
I had this 372 code when I replaced my opti .. bad opti improperly assembled key was not properly set .. confirmed as I installed opti with cap off and the old opti rotor position was off by 1//8 IN ...it was a spectra opti made in china .. returned and used my 21 yr old opti .. sealed the gasket ..
I myself had a bad opti due to seal issues. the cap seal on the 5 year old opti leaked causing spark issues .. then the ICM/coil also had small arcing which added to this problem .. on a dry day all good , on a damp day not good.
before replacing the NEW opti I would replace the ICM/coil assy.. It is a PITA but that is a start. reset codes and see if it works if not , then the NEW opti is bad. also the new opti may come with a connector these must be sealed at the exterior wire input to the connector OR it will leak into the optical sensor component .. also ALL new opti must be pressure tested to determine NO leaks .. I use a small hand pump and a gauge to see if it holds like 5 PSI..
the old OPTI may be good .. cleaning it and if necessary new cap/rotor.. my experience is the rotor bearing does wear out this is due to OZONE created by the normal opti operation and then if the venting harness is not properly venting it will kill the distributor due to the corrosive ozone gas.
explain how the old opti looked ,you check the opti venting harness ??? need vacuum gauge..
do not mess with the crank sensor that is not the problem , my guess the new opti is china crap.
driving in puddles is not good on the LT1 ... some put sealant all over the opti to keep the water out..I do not drive my 96 in bad weather or puddles.
Yeah,and/or a broken wire. The point is that I can unplug the crank sensor,and the car will start,and run perfectly fine. Before replacing a bunch of stuff,verify the wiring,and connectors are in good shape.
J-'s writeup and train of thought is pretty good at tracking the problem of poor quality control in non-oem Optis. There is no code for "You just installed a crappy aftermarket Opti with all-too-common misaligned optical reader".
If you never had one of the codes related to the CPS BEFORE you did an Opti r&r, then there is a definite logic flow that the CPS is not the cause of the code. It's likely whatever OTHER components communicate with it that is the root cause. The issues J- outlines have taken a while to accumulate based on the combined impact of guys ending up replacing their 20-year old distributors and the discontinuation of AC originals (with their associated quality control).
Too many of the aftermarkets are winding up with lo quality and poor assembly so that the only indication you have of problem is that trace code. I currently have a similar P0336 which came with the car from the seller who stated he had just paid $1,100 to have "a genuine dealer Opti" installed. The car runs great, but even AFTER I replaced the CPS ($50) the code remains. For reference, this supposed "genuine dealer AC Opti" has a black back (not yellow as an AC does), so the poor seller got reamed and I'm running a piece of junk Opti until digging in and swapping it out with a real AC oem I have from my old FWB along with new cap and rotor. I have to get at it because the car is due for inspection nect month and they won't give me another waiver.
So there. The only reason throwing so much detail is the thread title is perfect for future (probably definitely increasing) searches.
And of course what 1slow- added for another permutation on the same theme. For reference my wires leading away from the CPS rearward toward the starter are stiff and brittle like a boxed noodle. I bought the new plug/pigtail but it's only 3" long.
Ok here is an update. Went out and got an new Crank sensor and deleted the code. Symptoms remain the same. Starts right up when cold without no proplems. I let it get to operating temp and took it out for a spin around the block. Half way back is stalled and I couldn't get it started. Waited and after several more attempts it started back up. Drive a couple more hundred feet and stalled again and so on until I got it home. This time I had no codes. I took a vid of me attempting to start the vehicle
Ok so here are some items that I'm going to buy. Opti spark or should I just get a new rotor and cap? New optispark harness. New ignition control module and coil. Anything else I should get?
first just change the ICM/coil components.. the arcing in the old distributor will damage the ICM.. the coil should also be replaced if it is 21 yrs old esp where you live in high humidity ... then see if it runs good with not dying .. then if the 372 code comes back the opti must be replaced.. having gone thru this 372 with install of new opti it may take some time to throw the code.sometimes very fast..
so if you do have to replace the opti due to the 372 code install opti only .. do not put water pump on .. with a scan tool connected start engine see if it runs good and check for any codes .. run for like 20-30 sec.. only... if all good then complete the repair ..
what will happen on the 372 code the PCM will read the error as pending ,,,, then at a later time throw the CEL light on and label the failure as confirmed ... tricky
This makes sense, the coil will work fine until it's hot enough and then craps out, sends no spark and car shuts off. When trying to restart, it wont turn on because it's damaged and hot. Finally when cooled off the car will start back up. thanks.
For the OP, I'm just making sure we're all tracking the same through this with you. All those opti pics you posted are just the 20-year old distributor you took out, right? Not a whole lot to apply to progression of events beyond that, or pertaining to the suspect new Opti you have in there now except to show obvious and unusual scoring (not cracking) of the rotor, right?
If you're asking whether to ditch the crap new opti (you'll never get a refund, just another potentially crap replacement), or worth reusing the old opti with new parts then I'd seriously explore the Skip Wiess rebuilt solution for ? $100 ??
Yes, the assumption is that it's a 20 year old opti. The motor is a 355 so it has been taken off before. Yes, that scoring is unusual and kind of hard to figure out where it came from. When I first took it off the copper scoring was shinny like if it just happened. Not sure the route to go on the opti. I was asking due to me seeing a bunch of name brand opti's cap and rotors for about $150.00. Do you have a link to these rebuilt optis?
Today was the day, I wanted my baby back but it was not as successful as I thought it was going to be.
I got off work at 730am an went straight to O'reily and picked me up a ICM and coil. took the old one off which was the OE and bought some new plugs as well . I cleaned up the base and the heat sink. Put everything back together and started it up. waited till it was at operating temp and took it twice around the block without stalling. Was pretty happy at the time so I took it to the main road and after a 1/4 of a mile the engine stalled again and I rolled it to a near by parking lot where it is currently sitting. I decided to leave it there due to traffic and I had someone pick me up. headed to O'reily again and picked up a new opti spark and a new CTS. I'm going to wait until tonight to bring it home when there is no traffic. No codes were triggered.
Here are some pictures of the old ICM, Coil an spark plug. the white housing cracked.
Here are the new parts. the base and heat sink cleaned and put together.
and last but not least the new Opti with new plug which looks pretty decant with Life Time Warranty and new CTS. Ill be installing this prob tomorrow.
AC Delco electronics are what many here recommend. Discount parts houses use "lifetime" warranties to sell parts that few would install otherwise. If they function for a year,consider yourself fortunate...
Problem is that you still won't know. Use the diagnostic flow charts in the factory service manual. If you don't have a set,get them. Having the "real" manual(s) are critical if you plan to work on this type car.
the ICM mounting requires a conductive compound / called thermal compound . this is NOT grease/dielectric grease but a paste that is used like on your computer processor and other electronic components that require a heat dissipating metal ..
I understand that many people confuse this product withe the silicon that is used inside spark plug and distributor connections. This is why you need to see the word heatsink in the product.
As this is a high heat (underhood) automotive application I suggest GM's recommendation. There may be better products but some melt out of the area and cause more problems.
Juancolchado my comment was made because not all parts suppliers give you the heatsink silicone grease and you have to buy a packet of heatsink silicone grease separately.
Here is something that i noticed bringing the car home in the morning. With the new coil and module the car won't take as long or as many attempts to restart, three to five tries as in before It would take 5 to 10 minutes before it would even sound like it wants to start.
Because it does start faster , but not on the first crank it can be the plugs are fouled due to the weak poor spark with the old coil/ICM. I did replace my plugs after the coil/ICM replacing .. the plugs had 30K on them . they did not look all that great with the tip color.. engine starts now on the first crank perhaps 2 revs quick start and smooth.
so does the engine now run better and not stall... ?
Quick update. Put the new opti in, ran fine for a good while and I was scared so I then decided to push it and floor the gas pedal and the car shut off with the low oil pressure light coming on. I didn't think of anything at the time so I turned it back on and drove it cautiously. It was running good and code p0372 came back on my way to getting gas, I cleared it and got a new crank sensor. Drove it for a good 30 miles and noticed the new symptoms. When I would try and accelerate at a fast pace the car would feel like it would run rough and feel like it would shut off. If I would accelerate at a slow pace the car would feel fine and I managed to get up to 100mph on the highway with no hiccups. got it back home and a new code came up (P0336 crank sensor). I looked under the hood and noticed a bunch of oil all over the engine. The new seals failed and this would explain the reason for the ****ty feel when I would accelerate and loss of pressure. Today I got all new parts including a new opti, seals and gaskets. The opti seal and the back of the opti was dry so my guess is the water pump seal was the one that failed. I got everything off today and cleaned everything and prep to install for tomorrow. hopefully this is it.
Also I got a scan tool that reads live data.
Thanks to everyone that gave me suggestions and all the help. I really appreciate that. I love my baby.
I want to install new spark wires but I have edelbrok headers and the wires are running through the stock location and brackets. Passenger side is a mutha.... any tips or do I just re-route them from above and away from the headers?
Good heads-up and may add that to the list. On the wires overall I recall from the last time thinking if the ENTIRE change-out doesn't chew up at least 4 hours, -- then you didn't do it right. lol
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Chevy Impala SS Forum
1.9M posts
42.7K members
Since 2000
A forum community dedicated to Chevy Impala SS owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, maintenance, and more!