Misfire Under Load with no CEL

F

Frozen Blue

New member
I need some help here. I was logging in Sport mode this morning and when the car shifted to 3rd it fell flat on its face, threw a CEL, and began shuttering. Pulled over immediately and the car had a very rough idle. I shut the car off and checked for any codes and had none. Started the car back up and it ran fine. WTF? Checked the log when I got to work and everything looks ok. Had a FRP dip but it doesn't look to bad. AFRs were in check until that happened. WGDC, OAR, everything just zeroes out.

http://datazap.me/u/jawiedemann/wtf-modified?log=0&data=4-12-14-15-17-22&zoom=220-2514

Mods are:

170° thermostat
3 bar Map sensor
Currently tuning for 91 with Torrie

And yes before people jump on me, I emailed Torrie immediately and am waiting for a reply.
 
As soon as I saw this, I thought 2013+?  They have had problems with the FDMs, and this may have been the first warning of a future failure.  Have all recalls been performed on your SHO?  Check at http://owner.ford.com to be sure.  Could be the controller for the fuel pump also.  Should ultimately set a code though there were none at this time.  Good you checked before starting it back up as some codes get erased on restart.
 
SHOdded said:
As soon as I saw this, I thought 2013+?  They have had problems with the FDMs, and this may have been the first warning of a future failure.  Have all recalls been performed on your SHO?  Check at http://owner.ford.com to be sure.  Could be the controller for the fuel pump also.  Should ultimately set a code though there were none at this time.  Good you checked before starting it back up as some codes get erased on restart.
Click to expand...

No recalls done on it from what I can see.
 
Also sounds the car went into limp mode....ask torrie if he has changed the torque tables, and why.

I used to think they needed to be changed...when they do get changed the torque inverse tables need to be changed to match the torque tables ...if they dont, the torque calculations will be wrong and limp mode may result

Were you actually logging misfire counts?...the car falling on its face as you say doesnt  nessasarily mean misfire 
 
ajpturbo said:
Also sounds the car went into limp mode....ask torrie if he has changed the torque tables, and why.

I used to think they needed to be changed...when they do get changed the torque inverse tables need to be changed to match the torque tables ...if they dont, the torque calculations will be wrong and limp mode may result

Were you actually logging misfire counts?...the car falling on its face as you say doesnt  nessasarily mean misfire
Click to expand...

I'm still waiting on Torrie to get back to me but thanks for the help. I'll ask him.

I wasn't logging the Misfire PID but I think I'll add it now. The car is running normally still. I'm tempted to do a compression check this weekend. When the car gets put in Limp Mode does it idle rough? And does it reset the OAR?
 
I would say it could idle rough and i dont know about oar resetting but i would say maybe because i would think it reverts back to a base table rather than a scaled spark table learned from oar
 
Well it sounds like it was tune related thank God. I got an email from Torrie stating that he handled it. I don't like to think it could be injector or fuel pump related. I don't like the idea of a cylinder running lean due to an injector quitting while in boost.

And FDM, that's a new one. I've always called it "in-tank fuel pump" or "lpfp(low pressure fuel pump)". Learn something new everyday.
 
FDM is what Ford refers to the unit as, seeing as it can be a combination of fuel pump, filter, regulator, etc.
 
I thought the fdm was the box or controller and not the pump....the late model mustangs the FPDM is the box that drives the in tank pump...i would imagine the sho has one as well
 
Well, they do have an FPCM, or Fuel Pump Control Module in addition to the FDM.  Is that what you are thinking of, AJ?

Fuel Pump (FP) Control Module

The FP control module:

- is electronically operated by the PCM.
- controls voltage (10 or 12 volts) to the FP module depending on load.
Click to expand...

See the TSB for replacement of the FDM.  That's actually where I draw my reference from.  Doesn't mean I am not wrong, but ... :)
http://www.revbase.com/BBBMOTOR/TSb/DownloadPdf?id=182417
 
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