In-Tank Fuel Pump Electrical Failures

Scott Manager Claremont, California Posted   Latest  
Discussion
Driveability
Electrical
2007 Ford Expedition Limited 5.4L (5) 6-spd (6R75)—1FMFU195X7LA77014
Fuel Pump
Crank / No Start

Hello everyone, 

We had the above listed vehicle towed in with a no-start condition which we diagnosed as a defective fuel pump. Upon removal of the pump, our inspection revealed where the pump failed. I hadn't seen one fail like this before so I took a few high res pics and assembled a short video for anyone interested.

I'm assuming that the part that failed on the pump has something to do with electrical noise suppression, can anyone here back that assumption up?

Also, prior to this circuit going completely open, I'm curious as to just how safe a condition like this is. What if the fuel cap was left off and the fuel level ran low, could that have ultimately lead to a serious issue?

+11
Dmitriy Analyst
Toronto, Ontario
Dmitriy Default
   

Attached is the bulletin from Ford circa 2002 on installing a fuel pump RFI filter for vehicles with communication or high-end audio equipment: arrl​.​org/files/file/Tec…​.​pdf Possibly this became standard for some of the later models... What a crazy failure mode, though! Thanks for showing it to us.

+3 Default Ð Bounty Awarded
Bob Owner/Technician
East Longmeadow, Massachusetts
Bob Default
 

I remember this very issue was vigorously discussed when manufacturers first started putting fuel pumps in gas tanks. It was assumed that if the pump or wires arched out the tank could explode. I think time has proven that this is highly unlikely to happen. Now I would never say never but, If you look at the sheer number of motorized vehicles of all types that are on the road (over a billion) vs…

+5 Default Ð Bounty Awarded
Scott Manager
Claremont, California
Scott Default
 

Thanks for the insight Bob, much appreciated.

+1 Default Ð Bounty Awarded
Glen Owner/Technician
Arthur, Illinois
Glen Default
 

Is that an OE pump?

+1 Default Ð Bounty Awarded
Scott Manager
Claremont, California
Scott Default
 

I believe so: diag​.​net/file/f5a1p2bxa…

+1 Default Ð Bounty Awarded
Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Scott, That's wild! I've never seen one fail like that either. Would've been interesting to see what the current ramp of that pump looked like just prior to failure. Did you replace it with an O.E. pump or an aftermarket unit? Just wondering whether or not the new pump has that same noise suppressor on it. In any case, thanks for sharing this.

0 Default Ð Bounty Awarded
Scott Manager
Claremont, California
Scott Default
   

Replacement with OE, I’m not sure if the new one was equipped with the same but I’ll see what I can do to find out. Thanks,

0 Default Ð Bounty Awarded
Angel Technician
Boston, Massachusetts
Angel Default
 

Interesting failure, thanks for sharing with us. I wonder if by any chance this was caused by driver habits such as driving with low fuel for extended periods of time causing the pump to heat up excessively. Could be completely wrong but just wondering as to why.

+2 Default Ð Bounty Awarded
Samuel Technician
Somers Point, New Jersey
Samuel Default
   

High resistance = higher than expected heat, which would increase amps in the circuit. We recently had a Chevy Express Van, failed fuel pump. High Heat signs at the FP connector pin and pig tail. We replaced and assumed FP and Pigtail would do the trick. Temporarily it did, until the vehicle returned with the EXACT same symptom and customer complaint, intermittent NO Start... After an intense…

+1 Default Ð Bounty Awarded
Angel Technician
Boston, Massachusetts
Angel Default
 

Couldn’t agree more Samuel Bane. Was there any significant voltage drop on Either side of the circuit when the vehicle was diadnosed The first time?

+1 Default Ð Bounty Awarded
Samuel Technician
Somers Point, New Jersey
Samuel Default
 

Angel, love the thought process......As best that I can remember, no voltage drop test was performed after the repair. With that much heat, I now wish we would have tested it post repair! I am confident we would have found the issue by completing the diagnostic process, instead, we jammed ourselves up with a comeback....smh

+1 Default Ð Bounty Awarded
Angel Technician
Boston, Massachusetts
Angel Default
 

Happens to the best of us! its how we learn Trained by techs made this 2 part series you might find interesting. youtu​.​be/fIU_4LXi62M

+1 Default Ð Bounty Awarded
Samuel Technician
Somers Point, New Jersey
Samuel Default
 

Thank you!

0 Default Ð Bounty Awarded