CEL Flashing & Hesitation

[moem1090]

Well let me start off with saying how frustrating this is! I just left work to grab lunch and on the way back I started hearing almost like knock/flutter noise, check engine light started flashing, and performance completely fluctuated and sounded like crap. I scanned the car right away and pulled P0300, P0301 & P0305 cylinder misfires, P0087 fuel rail/system pressure too low. Any thoughts? I replaced the fuel injector for cylinder 6 last month.

[BiGMaC]

Well let me start off with saying how frustrating this is! I just left work to grab lunch and on the way back I started hearing almost like knock/flutter noise, check engine light started flashing, and performance completely fluctuated and sounded like crap. I scanned the car right away and pulled P0300, P0301 & P0305 cylinder misfires, P0087 fuel rail/system pressure too low. Any thoughts? I replaced the fuel injector for cylinder 6 last month.

Good ear!... you heard exactly what's happening. I appreciate the frustration...

A flashing CEL is the indication of significant and frequent misfire and potential engine and or cat damage.. even a backfire.... the manual says have it towed to a dealer and recommends not to drive it!

The manual is here: http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/13tauom3e.pdf

I got a P0087 when my LPFP fuel pump was failing... it could be the HPFP, but if the low pressure fails, then not enough fuel will get to the high pressure pump and fuel rail pressure drops...  That would explain the misfires in both bank 1 and 2.  The fuel control module in mine was also bad, but I did get a U code because of that.  When mine failed I was near the dealer and they came out and pushed it into the shop! Don't think the injector has anything to do with it given the multiple cylinders involved

....a simple fix like a coil failure or a bad wire connection may be it, but unlikely... but don't risk engine damage IMHO

[moem1090]

Well let me start off with saying how frustrating this is! I just left work to grab lunch and on the way back I started hearing almost like knock/flutter noise, check engine light started flashing, and performance completely fluctuated and sounded like crap. I scanned the car right away and pulled P0300, P0301 & P0305 cylinder misfires, P0087 fuel rail/system pressure too low. Any thoughts? I replaced the fuel injector for cylinder 6 last month.

Good ear!... you heard exactly what's happening. I appreciate the frustration...

A flashing CEL is the indication of significant and frequent misfire and potential engine and or cat damage.. even a backfire.... the manual says have it towed to a dealer and recommends not to drive it!

The manual is here: http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/13tauom3e.pdf

I got a P0087 when my LPFP fuel pump was failing... it could be the HPFP, but if the low pressure fails, then not enough fuel will get to the high pressure pump and fuel rail pressure drops...  That would explain the misfires in both bank 1 and 2.  The fuel control module in mine was also bad, but I did get a U code because of that.  When mine failed I was near the dealer and they came out and pushed it into the shop! Don't think the injector has anything to do with it given the multiple cylinders involved

....a simple fix like a coil failure or a bad wire connection may be it, but unlikely... but don't risk engine damage IMHO

Thanks for the response. I was thinking it is a fuel pump also. Luckily it happened for me as I was pulling back up to work and I have a shop but unfortunately all of my bays are full so no one can diagnose my car at the current moment. I am hoping it is something they can easily figure out so I can get the ball rolling on Monday. Considering that I do have catless down pipes do you think it is still a risk to drive? It is not doing it anymore

[BiGMaC]

Thanks for the response. I was thinking it is a fuel pump also. Luckily it happened for me as I was pulling back up to work and I have a shop but unfortunately all of my bays are full so no one can diagnose my car at the current moment. I am hoping it is something they can easily figure out so I can get the ball rolling on Monday. Considering that I do have catless down pipes do you think it is still a risk to drive? It is not doing it anymore

The risk of course is burning or bending a piston or piston rod (and the piston rods in the 3.5 are lacking IMHO due to not being forged, but cast)... your car is knocking because of the misfires of course... and the mixture is very lean if it is the fuel pump... but you hear the knock, even if you didn't check the KR... and predetonation is predetonation. I would not drive it. Ford is not omniscient, but I think the advise of their engineers is correct here... a new engine will cost $6K-$8K plus your time to install and troubleshoot, reprogram, etc... Towing is cheap comparison.  You'll decide of course, but I wouldn't drive it.

BTW, the fuel control module on mine did not show up on the OBDII, only the communication code, so if you change the pump and it dies at a stoplight, or at idle, especially if it won't restart...try the fuel control module first.

As an aside... this failure happened to me at 19K miles on a new '13... After the module and pump replaced it runs better than it ever did.. so I think these things can function suboptimally for a long time, hurting performance, before a DTC or noticeable abnormal routine driving behavior... this part is just my $0.02... I can't prove anything but better performance.

[moem1090]

Thanks for the response. I was thinking it is a fuel pump also. Luckily it happened for me as I was pulling back up to work and I have a shop but unfortunately all of my bays are full so no one can diagnose my car at the current moment. I am hoping it is something they can easily figure out so I can get the ball rolling on Monday. Considering that I do have catless down pipes do you think it is still a risk to drive? It is not doing it anymore

The risk of course is burning or bending a piston or piston rod (and the piston rods in the 3.5 are lacking IMHO due to not being forged, but cast)... your car is knocking because of the misfires of course... and the mixture is very lean if it is the fuel pump... but you hear the knock, even if you didn't check the KR... and predetonation is predetonation. I would not drive it. Ford is not omniscient, but I think the advise of their engineers is correct here... a new engine will cost $6K-$8K plus your time to install and troubleshoot, reprogram, etc... Towing is cheap comparison.  You'll decide of course, but I wouldn't drive it.

BTW, the fuel control module on mine did not show up on the OBDII, only the communication code, so if you change the pump and it dies at a stoplight, or at idle, especially if it won't restart...try the fuel control module first.

As an aside... this failure happened to me at 19K miles on a new '13... After the module and pump replaced it runs better than it ever did.. so I think these things can function suboptimally for a long time, hurting performance, before a DTC or noticeable abnormal routine driving behavior... this part is just my $0.02... I can't prove anything but better performance.

I just pulled it out out of the shop and all my fuel pressure readings are right at spec. The concern is no longer present so I'm I'm unsure how to move forward. The fuel control module I believe is underneath the rear seats so I may have them test it on Monday

[SHOdded]

You could always clear codes and see if it recurs, but it could be a very large risk.

[moem1090]

You could always clear codes and see if it recurs, but it could be a very large risk.

I'm not sure what to do exactly because it is an intermittent issue