P0321 Intermittent Issue
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P0321 Intermittent Issue
Alright. I have a 1994 Oldsmobile 98 3.8l with 175k on it.
I have loved this car since the day I got it. Never had a problem with it, until now. A month ago I took it on a little road trip. On the way up, it had no problems. While I was at my location, no problems. Came home, the drive home was fine. After I parked it and went to leave for work the next morning, once it was started, the engine light was on. I almost shed a tear because in the 10 years i'veowned this car, I have never seen the light on and I was beginning to think it would never be an issue. Codes revealed P0321 and a few others but the guy who scanned it only told me P0321.
I have been chasing my tail back and fourth for a month now trying to figure this out. If I disconnect the battery for a few seconds, the problem will go away. Until I shut the car off and re-start it. The light only comes on at startup, never while driving. If I drive the car with the light on, it will stumble on acceleration, it will take longer to shift from 1st to 2nd, and when at cruising speeds (55mph, on a highway) you can feel it stumble. This morning when I went to work, i started it and the light was off (not unusal for it just go away randomly) but while i was buckling my seatbeat i noticed the car missing. It would miss for a few seconds, and then idle fine, then miss, then idle fine. And once i got to work and it was warmed up, it didn't miss anymore.
I have tested a few different things, changed the wires (they were due) changed the coils because i had a set laying around. Havent dug much into wiring yet though.
Just looking for opinions.
Thanks so much!
I have loved this car since the day I got it. Never had a problem with it, until now. A month ago I took it on a little road trip. On the way up, it had no problems. While I was at my location, no problems. Came home, the drive home was fine. After I parked it and went to leave for work the next morning, once it was started, the engine light was on. I almost shed a tear because in the 10 years i'veowned this car, I have never seen the light on and I was beginning to think it would never be an issue. Codes revealed P0321 and a few others but the guy who scanned it only told me P0321.
I have been chasing my tail back and fourth for a month now trying to figure this out. If I disconnect the battery for a few seconds, the problem will go away. Until I shut the car off and re-start it. The light only comes on at startup, never while driving. If I drive the car with the light on, it will stumble on acceleration, it will take longer to shift from 1st to 2nd, and when at cruising speeds (55mph, on a highway) you can feel it stumble. This morning when I went to work, i started it and the light was off (not unusal for it just go away randomly) but while i was buckling my seatbeat i noticed the car missing. It would miss for a few seconds, and then idle fine, then miss, then idle fine. And once i got to work and it was warmed up, it didn't miss anymore.
I have tested a few different things, changed the wires (they were due) changed the coils because i had a set laying around. Havent dug much into wiring yet though.
Just looking for opinions.
Thanks so much!
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code refers to a faulty crankshaft position sensor
this is a common problem on these cars, in most cases, the car will stop running, in some cases, it will randomly start to missfire..
so get a new crankshaft position sensor and your ride should be back to normal
this is a common problem on these cars, in most cases, the car will stop running, in some cases, it will randomly start to missfire..
so get a new crankshaft position sensor and your ride should be back to normal
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Thanks for your reply, I could make a valid case for the crank sensor being bad, because looking down at the connector it seems to be in the path of an oil leak and is covered in oil.
Another symptom I forgot to mention is that when the engine light comes on, the "Traction Off" light comes on and I wont have traction control. But if the light goes off like it does, so will the traction light. Just thought I'd mention that while i was thinking about it.
Thanks!
Another symptom I forgot to mention is that when the engine light comes on, the "Traction Off" light comes on and I wont have traction control. But if the light goes off like it does, so will the traction light. Just thought I'd mention that while i was thinking about it.
Thanks!
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From: Windsor, Ontario / Detroit, Michigan
A failing/failed crank shaft position sensor does not result in misfires. CPS failures are very common on the 3.8, but when they happen it shuts the engine down like someone flipped a switch. I think it more likely this is a PCM or an ICM issue. 1994 and 1995 have a high failure rate on PCM'*. I would start by checking and cleaning the electrical connections at the PCM and the ICM (misaligned pins, broken pins, corrosion, etc.)
After you check and clean the wire connections, take your car to the local parts store and ask them to scan for diagnostic trouble codes. Most parts stores will do this at no charge to you. Record all the codes, and report back here with the findings. Those "few others" you did not record could be very relevant.
If not a wiring issue, I am leaning toward a bad ICM. Most people would tell you to get one from a junk yard but at $140 (rockauto.com) for a new one I would put a new one in.
If the ICM is not the problem, you probably have to replace the ECM. Since this was a common failure for the 94'* and a lot of vehicles used the same ECM, there are lots out there. I would go the junk yard route on this one. You can use any of the compatible ones if you simply pull the access cover and change the blue eprom chip with the one from your ECM.
In any case, inspect and clean the wire connections first, then have the car scanned for DTC'* and report the findings. Don't start buying parts yet.
After you check and clean the wire connections, take your car to the local parts store and ask them to scan for diagnostic trouble codes. Most parts stores will do this at no charge to you. Record all the codes, and report back here with the findings. Those "few others" you did not record could be very relevant.
If not a wiring issue, I am leaning toward a bad ICM. Most people would tell you to get one from a junk yard but at $140 (rockauto.com) for a new one I would put a new one in.
If the ICM is not the problem, you probably have to replace the ECM. Since this was a common failure for the 94'* and a lot of vehicles used the same ECM, there are lots out there. I would go the junk yard route on this one. You can use any of the compatible ones if you simply pull the access cover and change the blue eprom chip with the one from your ECM.
In any case, inspect and clean the wire connections first, then have the car scanned for DTC'* and report the findings. Don't start buying parts yet.
Last edited by 2kg4u; Aug 10, 2016 at 08:45 AM.
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A failing/failed crank shaft position sensor does not result in misfires. CPS failures are very common on the 3.8, but when they happen it shuts the engine down like someone flipped a switch. I think it more likely this is a PCM or an ICM issue. 1994 and 1995 have a high failure rate on PCM'*. I would start by checking and cleaning the electrical connections at the PCM and the ICM (misaligned pins, broken pins, corrosion, etc.)
After you check and clean the wire connections, take your car to the local parts store and ask them to scan for diagnostic trouble codes. Most parts stores will do this at no charge to you. Record all the codes, and report back here with the findings. Those "few others" you did not record could be very relevant.
If not a wiring issue, I am leaning toward a bad ICM. Most people would tell you to get one from a junk yard but at $140 (rockauto.com) for a new one I would put a new one in.
If the ICM is not the problem, you probably have to replace the ECM. Since this was a common failure for the 94'* and a lot of vehicles used the same ECM, there are lots out there. I would go the junk yard route on this one. You can use any of the compatible ones if you simply pull the access cover and change the blue eprom chip with the one from your ECM.
In any case, inspect and clean the wire connections first, then have the car scanned for DTC'* and report the findings. Don't start buying parts yet.
After you check and clean the wire connections, take your car to the local parts store and ask them to scan for diagnostic trouble codes. Most parts stores will do this at no charge to you. Record all the codes, and report back here with the findings. Those "few others" you did not record could be very relevant.
If not a wiring issue, I am leaning toward a bad ICM. Most people would tell you to get one from a junk yard but at $140 (rockauto.com) for a new one I would put a new one in.
If the ICM is not the problem, you probably have to replace the ECM. Since this was a common failure for the 94'* and a lot of vehicles used the same ECM, there are lots out there. I would go the junk yard route on this one. You can use any of the compatible ones if you simply pull the access cover and change the blue eprom chip with the one from your ECM.
In any case, inspect and clean the wire connections first, then have the car scanned for DTC'* and report the findings. Don't start buying parts yet.
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True Car Nut
Joined: Sep 2006
Posts: 4,816
Likes: 245
From: Windsor, Ontario / Detroit, Michigan
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