Vallee
forum member
Folks,
I am at a total loss with resolving this issue.
Without getting into too much boring details, here’s a general background of my situation. After I finished building my engine late last summer I contacted JDM and asked them if they could supply me a safe “turnkey” tune until I could get to a dyno and they did. The car ran ok however the tune was very rich and kept throwing codes (P0175) and subsequently I could not get it to pass NYS emissions. So it was suggested that I try reaching out to Lito, so I did. He is great, we got the car to pass emissions and run decent and now we’ve been working on slowly dialing the car in. Along the way I’ve had this annoying hesitation (misfire) issues with WOT acceleration under a load. The best way I can explain it is, it acts like you cut the ignition power and then turned it back on and off and on again…
Over the past winter I did the following things to try to fix the issue:
- Verified all vacuum lines for leaks, and checked all wire connections.
- Changed out the MDS coil packs back to FORD OEM’s P/N: M-12029-3V (Brown Boots)
- Replaced the old 6G with a new DOB Denso high output 165A alternator.
Fast forward to this spring, Lito asked me to get some logs in a 3rd gear WOT run, boost was reporting a tad over 15psi and the car started breaking up again (probably started at around 3400 rpm and up), just as it did last fall… Just as before the wrench light flickered and the car went into limp mode. No CEL codes were stored.
Lito and I reviewed the log and saw nothing out of the ordinary. Very Puzzling…
- @ WOT the AFR between 10~11:1
- Batt Volts 13.6v
- Spark Adv 12
Per the request of Lito I pulled the plugs for a visual inspection, overall they looked ok but did have a hint of white residue around the electrode, and all were visually consistent with each other. Gaps are verified at .028. Plugs are FRPP NGK Iridium p/n ZNAR7AIX 7554
Image of the plugs below:
Screen shot image of the WOT Log with misfire is attached below:
I recently checked all chassis ground connections. As I had the engine bay smoothed and painted while the engine was out, and I was thinking the ground lugs may not be getting proper ground contact to the chassis and causing an electrical issue. However, I retested and although it did seem to help the misfire is still there.
I replaced the battery (found my old red top was not holding charge over time), have not yet tested it.
At this point I am thinking it could be a crank sensor? Clogged cats? Bad driver in the PCM?? Clogged injectors? Fuel pump failing (not sure it’s a fuel issue)? Perhaps the plugs are just junk? Also, surprisingly, it appears that the MSD COP's seemed to respond better then the OEM’s…
For what it’s worth, my old engine would misfire kind of like this whenever I down shifted and stabbed the throttle. Only now it’s all the time under WOT.I just thought it was the tune and lived with it... Now I am not sure..
For Reference - Here is a basic list of my build:
- 2005 Mustang GT (Standard 5sp)
- M-6009-A463SC FRPP, 4.6L 3V Aluminum Forged Short Block 8.7:1 CR for SC
- 127350 Comp Cams, Stage 2 Blower Camshafts
- Vallee’s Custom 3” 8 rib blower pulley, I see just under 16 psi of boost.
- 918018 ATI, Super Damper Serpentine Series 8rib Harmonic Balancer.
- M-6050/6049-N3VPA, Ford Racing stage-1 CNC ported Modular Cylinder Heads
- M-12405-3V12MM FRPP NGK Iridium #ZNAR7AIX-7554 Spark Plug - 3V 12MM gapped at .028
- VMP’s TVS high flow elbow.
- Roush Eaton TVS/R2300 Supercharger
- GT500 TB & Fuel Pump
- Kooks 1-3/4 LT Headers with the Green Catted 3” H-Pipe.
- ID1000 injectors with OEM GT500 fuel rails
- Tiresize is 255/45zR18 103W
- Rear DifGear ratio is 3.73:1
Here is the link to my build thread:
http://www.s197forum.com/threads/vallee’s-forged-4-6-aluminator-build-thread.125843/
I am open to any ides and opinions... thanks Guys!
Regards
Adam
I am at a total loss with resolving this issue.
Without getting into too much boring details, here’s a general background of my situation. After I finished building my engine late last summer I contacted JDM and asked them if they could supply me a safe “turnkey” tune until I could get to a dyno and they did. The car ran ok however the tune was very rich and kept throwing codes (P0175) and subsequently I could not get it to pass NYS emissions. So it was suggested that I try reaching out to Lito, so I did. He is great, we got the car to pass emissions and run decent and now we’ve been working on slowly dialing the car in. Along the way I’ve had this annoying hesitation (misfire) issues with WOT acceleration under a load. The best way I can explain it is, it acts like you cut the ignition power and then turned it back on and off and on again…
Over the past winter I did the following things to try to fix the issue:
- Verified all vacuum lines for leaks, and checked all wire connections.
- Changed out the MDS coil packs back to FORD OEM’s P/N: M-12029-3V (Brown Boots)
- Replaced the old 6G with a new DOB Denso high output 165A alternator.
Fast forward to this spring, Lito asked me to get some logs in a 3rd gear WOT run, boost was reporting a tad over 15psi and the car started breaking up again (probably started at around 3400 rpm and up), just as it did last fall… Just as before the wrench light flickered and the car went into limp mode. No CEL codes were stored.
Lito and I reviewed the log and saw nothing out of the ordinary. Very Puzzling…
- @ WOT the AFR between 10~11:1
- Batt Volts 13.6v
- Spark Adv 12
Per the request of Lito I pulled the plugs for a visual inspection, overall they looked ok but did have a hint of white residue around the electrode, and all were visually consistent with each other. Gaps are verified at .028. Plugs are FRPP NGK Iridium p/n ZNAR7AIX 7554
Image of the plugs below:
Screen shot image of the WOT Log with misfire is attached below:
I recently checked all chassis ground connections. As I had the engine bay smoothed and painted while the engine was out, and I was thinking the ground lugs may not be getting proper ground contact to the chassis and causing an electrical issue. However, I retested and although it did seem to help the misfire is still there.
I replaced the battery (found my old red top was not holding charge over time), have not yet tested it.
At this point I am thinking it could be a crank sensor? Clogged cats? Bad driver in the PCM?? Clogged injectors? Fuel pump failing (not sure it’s a fuel issue)? Perhaps the plugs are just junk? Also, surprisingly, it appears that the MSD COP's seemed to respond better then the OEM’s…
For what it’s worth, my old engine would misfire kind of like this whenever I down shifted and stabbed the throttle. Only now it’s all the time under WOT.I just thought it was the tune and lived with it... Now I am not sure..
For Reference - Here is a basic list of my build:
- 2005 Mustang GT (Standard 5sp)
- M-6009-A463SC FRPP, 4.6L 3V Aluminum Forged Short Block 8.7:1 CR for SC
- 127350 Comp Cams, Stage 2 Blower Camshafts
- Vallee’s Custom 3” 8 rib blower pulley, I see just under 16 psi of boost.
- 918018 ATI, Super Damper Serpentine Series 8rib Harmonic Balancer.
- M-6050/6049-N3VPA, Ford Racing stage-1 CNC ported Modular Cylinder Heads
- M-12405-3V12MM FRPP NGK Iridium #ZNAR7AIX-7554 Spark Plug - 3V 12MM gapped at .028
- VMP’s TVS high flow elbow.
- Roush Eaton TVS/R2300 Supercharger
- GT500 TB & Fuel Pump
- Kooks 1-3/4 LT Headers with the Green Catted 3” H-Pipe.
- ID1000 injectors with OEM GT500 fuel rails
- Tiresize is 255/45zR18 103W
- Rear DifGear ratio is 3.73:1
Here is the link to my build thread:
http://www.s197forum.com/threads/vallee’s-forged-4-6-aluminator-build-thread.125843/
I am open to any ides and opinions... thanks Guys!
Regards
Adam