Spark blowout/misfire / p305 cylinder 5 code
#1
08-26-2017, 05:51 PM
Join Date: Apr 2016
Location: Houston
Age: 42
Posts: 8
Rep Power: 0 
Spark blowout/misfire / p305 cylinder 5 code
Here is the story:
Vehicle: 2001 turbo, flash (1bar, not sure what company) and exhaust (I put on). I have owned the car for about 18 months and have put on about 3k miles (2001 turbo/44k miles).
- Car seemed to develop a slight miss after adding my exhaust (speed tech competition pipe with cats) which was only noticeable under light acceleration (around 3k) from time to time.
- Recently pulled hard a couple times to redline on the way to work. Parked the car and all seemed fine. When I went to drive home that evening (~95F outside), I accelerated onto the freeway and as soon as it started to build boost it felt like I had hit the rev limiter (spark blowout miss). Was unclear what happened so tried accelerating moderately and it did it again briefly and the CEL started flashing. I thought great this is all I need, was about to pull over and call a tow when the light stopped flashing and went out. Not wanting to test the car again under throttle, I kept it at ~2800-3k rpm highway driving and limped her home. Drove fine when keeping steady at 3k until I pulled into the driveway and was running rough with misses under idle / light throttle.
- Pulled the code from a simple obd reader and it came up with a pending cylinder 5 misfire. Did some research and thought, it has to be the coils/plugs (didn't think they had ever been changed and I was right). Ordered the updated 997 coils, FR6LDC plugs (gapped them to ~0.27/0.28) and installed them. The plugs I took out were very dirty, perhaps the tune is rich (get a considerable amount of soot on tailpipes bumper/oil consumption is within Porsche spec/~1qt per 900miles). Checked the bracket which cracks when replacing the coils and they didn't appear to be cracked.
- Just finished up this afternoon and was pumped to fire it up, started up and still a misfire! I didn't drive the car as it it is still on stands. Seems to be running better than it was but there is a noticeable miss under idle (every 5-10 seconds) which becomes more noticeable under steady rpm (say at 1800rpm). Didn't seem to miss when revs increased to 4.5k No codes or pending codes yet (using cheap OBD tool). Safe to say it doesn't seem like the issue has been fixed.
Thoughts from you experienced gents out there as to what to look at next? Maybe MAF sensor? Something more serious? At a loss at this point. Will likely be picking up a Durametric to aid in the troubleshooting. Any help would be appreciated!
Vehicle: 2001 turbo, flash (1bar, not sure what company) and exhaust (I put on). I have owned the car for about 18 months and have put on about 3k miles (2001 turbo/44k miles).
- Car seemed to develop a slight miss after adding my exhaust (speed tech competition pipe with cats) which was only noticeable under light acceleration (around 3k) from time to time.
- Recently pulled hard a couple times to redline on the way to work. Parked the car and all seemed fine. When I went to drive home that evening (~95F outside), I accelerated onto the freeway and as soon as it started to build boost it felt like I had hit the rev limiter (spark blowout miss). Was unclear what happened so tried accelerating moderately and it did it again briefly and the CEL started flashing. I thought great this is all I need, was about to pull over and call a tow when the light stopped flashing and went out. Not wanting to test the car again under throttle, I kept it at ~2800-3k rpm highway driving and limped her home. Drove fine when keeping steady at 3k until I pulled into the driveway and was running rough with misses under idle / light throttle.
- Pulled the code from a simple obd reader and it came up with a pending cylinder 5 misfire. Did some research and thought, it has to be the coils/plugs (didn't think they had ever been changed and I was right). Ordered the updated 997 coils, FR6LDC plugs (gapped them to ~0.27/0.28) and installed them. The plugs I took out were very dirty, perhaps the tune is rich (get a considerable amount of soot on tailpipes bumper/oil consumption is within Porsche spec/~1qt per 900miles). Checked the bracket which cracks when replacing the coils and they didn't appear to be cracked.
- Just finished up this afternoon and was pumped to fire it up, started up and still a misfire! I didn't drive the car as it it is still on stands. Seems to be running better than it was but there is a noticeable miss under idle (every 5-10 seconds) which becomes more noticeable under steady rpm (say at 1800rpm). Didn't seem to miss when revs increased to 4.5k No codes or pending codes yet (using cheap OBD tool). Safe to say it doesn't seem like the issue has been fixed.
Thoughts from you experienced gents out there as to what to look at next? Maybe MAF sensor? Something more serious? At a loss at this point. Will likely be picking up a Durametric to aid in the troubleshooting. Any help would be appreciated!
Last edited by Stoopstn; 08-26-2017 at 05:53 PM.
#2
08-26-2017, 06:26 PM
First thing I would start with would be to reach out to one of the reputable tuners on this board to have them look in to the tune that's in your car (Markski, Sam@ByDesign). Since it's an unknown tune, you may need to make some tweaks and it's always good peace of mind to know that your tune is safe.
While you're doing that, and the car is still apart, do a boost leak test. It may not be the source of this particular issue, however it sounds like this is a fairly new car to you and I'm assuming it hasn't been done during your ownership. It's very simple to do and will make any boost leak apparent, which you can address.
Also, since you noticed the car began to misfire after you installed the new exhaust, I would be looking in that area first. Did you try to reinstall the stock exhaust to see if the Miss went away? Is everything connected on the new exhaust, particularly O2 sensors?
Before you changed plugs and coils and got th CEL, did the car make full boost?
While you're doing that, and the car is still apart, do a boost leak test. It may not be the source of this particular issue, however it sounds like this is a fairly new car to you and I'm assuming it hasn't been done during your ownership. It's very simple to do and will make any boost leak apparent, which you can address.
Also, since you noticed the car began to misfire after you installed the new exhaust, I would be looking in that area first. Did you try to reinstall the stock exhaust to see if the Miss went away? Is everything connected on the new exhaust, particularly O2 sensors?
Before you changed plugs and coils and got th CEL, did the car make full boost?
#3
08-26-2017, 06:38 PM
Join Date: Apr 2016
Location: Houston
Age: 42
Posts: 8
Rep Power: 0
Agree, on the tune, it was something that has been bothering me (not knowing) and was planning on fixing.
Funny you mention the boost leak as I picked up the materials today from Home Depot to do this while bumper etc was off. Will likely get to that tomorrow hopefully.
Car ran like a champ before, would hit 1 (sometimes 1.1bar) at full throttle on highway. The miss (more like a slight hesitation) after adding the exhaust was very subtle and I only noticed every second or third drive and under very light driving (wouldn't do it all the time). Have not tried installing the old exhaust given it was so subtle but something is definitely wrong now. The O2 sensors are all connected on the new exhaust.
Car has been very good operational wise. The only other unusual things I can think of are:
1) I filled up from a gas station I don't usually fuel up at on last fill (half tank remaining).
2) A few months ago I started the car and a steady honking/horn sound was present for 15seconds or so from the front of the car which was preceded by a strong fuel smell. Never experienced it before/since.
Funny you mention the boost leak as I picked up the materials today from Home Depot to do this while bumper etc was off. Will likely get to that tomorrow hopefully.
Car ran like a champ before, would hit 1 (sometimes 1.1bar) at full throttle on highway. The miss (more like a slight hesitation) after adding the exhaust was very subtle and I only noticed every second or third drive and under very light driving (wouldn't do it all the time). Have not tried installing the old exhaust given it was so subtle but something is definitely wrong now. The O2 sensors are all connected on the new exhaust.
Car has been very good operational wise. The only other unusual things I can think of are:
1) I filled up from a gas station I don't usually fuel up at on last fill (half tank remaining).
2) A few months ago I started the car and a steady honking/horn sound was present for 15seconds or so from the front of the car which was preceded by a strong fuel smell. Never experienced it before/since.
Last edited by Stoopstn; 08-26-2017 at 06:43 PM.
#5
12-12-2017, 09:38 AM
Check the seal where the fuel pump is accessed for leak sign.
If there is a problem with the fuel vapor system there might be a pending error code which can help pinpoint the source of the problem.
#6
12-15-2017, 10:26 PM
perfect plugs, gap and coils.. and yet still reads as a cracked coil? i'd check the integrity of all wiring and ensure your coil/plug swap isn;t somehow amiss.
my next step would in inspecting any/all fuel parts beginning with injectors possibly being clogged it only takes 1or 2 ) then FF then F pump, and actually last i would suspect a maf. though a new one has NEVER hurt a "tuned" tt ( which you presumably have! )
GL.
my next step would in inspecting any/all fuel parts beginning with injectors possibly being clogged it only takes 1or 2 ) then FF then F pump, and actually last i would suspect a maf. though a new one has NEVER hurt a "tuned" tt ( which you presumably have! )
GL.
