ChrisWoodard
Member
- Joined
- Dec 3, 2019
- Threads
- 3
- Messages
- 12
- Reaction score
- 19
- Location
- White Oak, TX
- First Name
- Chris
- Vehicle(s)
- 2019 Roush RS3
- Thread starter
- #1
I am looking for some advice on dealing with a misfire issue. Sorry it's a long post... but I think the details matter.
A little history... the car is a 2019 Mustang Roush RS3 with an A10. It is a late build so it had the 2020+ phase 2 heat exchanger installed at Roush. The car is completely stock and had a bad motor when I bought it so I installed a new motor. While the motor was out I installed a Boundary OPG set. The car ran perfect without any issues for 650 miles. I learned that I had a set of the "G2" OPG that Boundary had recalled... so I removed the set and replaced them with a new set. They were nice to send a new set of gears... but what a pain to replace in the car. Anyway, after putting the car back together, I noticed that my check engine light came on. Codes P0300, P0302 & P0316 (with an occasional P0304 and P0306) The driveability of the car was fine (maybe a little rough at idle at times but nothing to complain about) and perfect while on the gas. My first step... even though I didn't think it was necessary, was to perform a misfire monitor neutral profile correction... but it didn't change anything. Next step was to swap coils and plugs between #1 and #2 and the issue stayed predominately with #2. Next step was a compression check and all cylinders (197, 197, 194, 197, 197, 199, 199, 200. #1-#8 in order with the engine warm and throttle blade closed). Next step was to replace #2 upstream injector... no changes. This is when I learned of the Roush TSB 22-0215-BA to correct a similar issue a lot of people were having with roushchargers. I had my local Ford service center upgrade to the latest Roush software... and the misfire issue remained. I drained the fuel and put in some fresh fuel and no change. I am frustrated at this point but determined to fix the issue. Next was to pull the supercharger and swap the direct injectors between #1 & #2... and #5 & #6. While I was in there, I replaced the knock sensor harness and both direct injector harnesses. I also replaced the entire engine harness. After putting it all back together, I noticed that I am STILL getting misfires on cylinder #2. When I am monitoring misfires on my scanner, they only occur at idle and only when the engine is under load. The car idles great most of the time... but you can feel the car get a little rough and watch the misfire count stack up on cylinder #2. This rough idle will take place only for a few seconds... and then clear right up and the misfires stop. The CEL is currently off and I am on day 2 without it on... but I can still feel the rough idle at times and there is a P0302 code stored but no light.
UUGH!!! I don't know what else to try. I have installed multiple sets of OPG so I am confident that I timed the cams correctly. If I was off a tooth, I would think it would show up in a compression check. I wouldn't think the tune is the issue since the problem existed both before and after then new tune. Is it a fluke that it happened directly after the oil pump gear install... or are they related. I am ready to throw in the towel but I thought I would check with the experts here to see if anyone had any words of wisdom... before I sell it cheap and get a plaid. =-)
A little history... the car is a 2019 Mustang Roush RS3 with an A10. It is a late build so it had the 2020+ phase 2 heat exchanger installed at Roush. The car is completely stock and had a bad motor when I bought it so I installed a new motor. While the motor was out I installed a Boundary OPG set. The car ran perfect without any issues for 650 miles. I learned that I had a set of the "G2" OPG that Boundary had recalled... so I removed the set and replaced them with a new set. They were nice to send a new set of gears... but what a pain to replace in the car. Anyway, after putting the car back together, I noticed that my check engine light came on. Codes P0300, P0302 & P0316 (with an occasional P0304 and P0306) The driveability of the car was fine (maybe a little rough at idle at times but nothing to complain about) and perfect while on the gas. My first step... even though I didn't think it was necessary, was to perform a misfire monitor neutral profile correction... but it didn't change anything. Next step was to swap coils and plugs between #1 and #2 and the issue stayed predominately with #2. Next step was a compression check and all cylinders (197, 197, 194, 197, 197, 199, 199, 200. #1-#8 in order with the engine warm and throttle blade closed). Next step was to replace #2 upstream injector... no changes. This is when I learned of the Roush TSB 22-0215-BA to correct a similar issue a lot of people were having with roushchargers. I had my local Ford service center upgrade to the latest Roush software... and the misfire issue remained. I drained the fuel and put in some fresh fuel and no change. I am frustrated at this point but determined to fix the issue. Next was to pull the supercharger and swap the direct injectors between #1 & #2... and #5 & #6. While I was in there, I replaced the knock sensor harness and both direct injector harnesses. I also replaced the entire engine harness. After putting it all back together, I noticed that I am STILL getting misfires on cylinder #2. When I am monitoring misfires on my scanner, they only occur at idle and only when the engine is under load. The car idles great most of the time... but you can feel the car get a little rough and watch the misfire count stack up on cylinder #2. This rough idle will take place only for a few seconds... and then clear right up and the misfires stop. The CEL is currently off and I am on day 2 without it on... but I can still feel the rough idle at times and there is a P0302 code stored but no light.
UUGH!!! I don't know what else to try. I have installed multiple sets of OPG so I am confident that I timed the cams correctly. If I was off a tooth, I would think it would show up in a compression check. I wouldn't think the tune is the issue since the problem existed both before and after then new tune. Is it a fluke that it happened directly after the oil pump gear install... or are they related. I am ready to throw in the towel but I thought I would check with the experts here to see if anyone had any words of wisdom... before I sell it cheap and get a plaid. =-)
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