Misfire issue. Yep, I need help...
#1
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Misfire issue. Yep, I need help...
2004 MSM with 22,000 miles. A few upgrades: FM intake, FM downpipe, FM O2 signal modifier (the old kind), ebay intercooler, MBC. We rarely drive the car so it sits 3-6 months at a time (yeah, I know). We are currently getting CELs concerning misfire issues. It started as P0304 (misfire on #4) and occasionally P0301 (cylinder #1) or P0300 (multiple cylinders). I figured it was the #4/#1 coil so I replaced it. Since then I started getting misfire on other cylinders so I changed out the plug wires and CAS (crank sensor - set to around 1 credit card gap from the crank "****"). Still having the issue. Any ideas???
#5
2004 MSM with 22,000 miles. A few upgrades: FM intake, FM downpipe, FM O2 signal modifier (the old kind), ebay intercooler, MBC. We rarely drive the car so it sits 3-6 months at a time (yeah, I know). We are currently getting CELs concerning misfire issues. It started as P0304 (misfire on #4) and occasionally P0301 (cylinder #1) or P0300 (multiple cylinders). I figured it was the #4/#1 coil so I replaced it. Since then I started getting misfire on other cylinders so I changed out the plug wires and CAS (crank sensor - set to around 1 credit card gap from the crank "****"). Still having the issue. Any ideas???
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Edit:
WOW, found a new cam sensor on Ebay for $16 and used a $12 paypal bonus so $4 shipped. Nice (they are $90 at AutoZone).
I'll let you know how it works...
Last edited by rmcelwee; 07-05-2015 at 02:30 PM.
#12
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Just changed the Cam Angle Sensor. Took the car for a drive. Started out slow and kept out of boost (negative pressure). Ran the car at 5000 rpm in 3rd for a while with no problems. Approached 6000 rpm and still no problems. Gave it a little gas (I'm assuming it blipped the PSI) and it threw a "cylinder #2 misfire" and "random cylinder misfire". It seems like it has something to do with the car going into boost.
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I've never had it off (22k miles on the clock). As I said, I can drive you around all day at 5000 RPM and you would never notice a problem. I'm going to try to find an OBDII datalogger of some sort and see if I can visually see what is going on.
#15
Are the plugs gaped properly? Could be spark blow out. Also, do you know how close you are to maxing out the stock injectors? What do you have the MBC set to? Any way you can get a datalog of a pull / the event?
Edit - I see you got your comment in before mine about the datalogger, that would be extremely helpful.
Edit - I see you got your comment in before mine about the datalogger, that would be extremely helpful.
#16
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Are the plugs gaped properly? Could be spark blow out. Also, do you know how close you are to maxing out the stock injectors? What do you have the MBC set to? Any way you can get a datalog of a pull / the event?
Edit - I see you got your comment in before mine about the datalogger, that would be extremely helpful.
Edit - I see you got your comment in before mine about the datalogger, that would be extremely helpful.
Still have not found any datalogging software. They say Torque Pro will do it but I have not seen any info about that.
#17
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I banged off my rev limiter for 30 seconds or so as a test and it didn't throw a code.
The second test was very interesting and will probably lead to the solution...
I backed my MBC out (to around 5-6 PSI) and could not get the car to throw a code. Maybe I need to look at the plugs again (blowing the spark at 12PSI or whatever I was running)??? Suggestions on what plug/gap to use (for those of you who have it memorized)?
The second test was very interesting and will probably lead to the solution...
I backed my MBC out (to around 5-6 PSI) and could not get the car to throw a code. Maybe I need to look at the plugs again (blowing the spark at 12PSI or whatever I was running)??? Suggestions on what plug/gap to use (for those of you who have it memorized)?
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I was having a random miss while cruising. In my brief thread, someone suggested coils or CAS. I removed all connections, made sure they were clean, and reconnected. Not sure what actually did the trick, but it seems to be gone.
I'd check coil connections, including the wires into the igniter connector itself, and the wires going into the CAS connector. Something must have been just loose enough to be making poor contact.
I'd check coil connections, including the wires into the igniter connector itself, and the wires going into the CAS connector. Something must have been just loose enough to be making poor contact.
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Ok, after a few hundred in parts (new coils, plugs, wires, Crank Angle Sensor, Cam Angle Sensor, etc) it seems like boost pressure may have been the issue the whole time. I cannot get the car to throw a code now. I'm running around 8 PSI now instead of the 11 or whatever I was running before. I'm calling this fixed...
Oh, thanks to all you guys who helped. I really appreciate it!
Oh, thanks to all you guys who helped. I really appreciate it!