Fuel Pump fuse (JMS BAP)

[lshin037]

Hopefully someone can help me here.

My car will not start all of a sudden. The car will crank but won't start. I have a JMS BAP installed. I bypassed the BAP and the car still won't start. I noticed that the BAP itself isn't turning on. I read a thread on here where the same thing happened and it turned out that fuel pump got fried. I was about to order a fuel pump but thought I'd take another look. I found out the the fuel pump fuse (the 30a fuse in the engine compartment) has blown. This puts me a bit at ease but I won't know for sure if replacing a fuse will fix the issue (pump could be fried). Assuming that it is just the fuse, would it be safe to replace the fuse with a higher rated fuse? Like 35A or 40A?

 

[H-TownMachI]

My neighbor had an issue after install. He kept blowing the 30 amp fuel pumps fuse. The fuse kept blowing even after the BAP was bypassed. It turned out to me the module on the FPDM.

 

[lshin037]

Thanks. So he just replaced the fpdm and all is well?

 

[H-TownMachI]

Yea, the the part cost about $25. I swapped in one of my FPDM's to confirm.

9D370
Ford
Engine Fuel Control Module
MOD 5.0L-4V Dual Over Head Cam SEFI NA ; Used For Fuel Pump Relays
$25.30

 

[Vikyank]

I had the same issue when I installed my first JMS bap. I bought a spare fpdm and keep extra fuses in the care as cheap insurance.

 

[lshin037]

I just tried replacing the fuse and it keeps blowing. Where did you get the fpdm? Is this something readily available at the dealership parts store?

 

[466roller]

May be worth checking the wiring for a short?

 

[lshin037]

Checking the wiring will be next if replacing the fpdm doesn't work. But I doubt it's the wiring. It's been working for months and I haven't worked on the car since. Hopefully the dealer has these in stock

 

[Vikyank]

Trust me the fpdm is shorted. Same exact problem I encountered because of my BAP. It's only $25 new from ford. He posted the part number above. You can also go to fordparts.com and order it online or just go into your closest dealer.

 

[lshin037]

I did exactly that. I actually ordered two so I can have a spare as well. Hopefully the dealer has it in stock and I can pick it up tomorrow.

 

[lshin037]

So I replaced the FPDM and the car started up. While working on this issue, I noticed that my JMS bap was always blinking when it should only be blinking when when the pedal is at 50% or more. The only time it'll stop blinking is when I unplug the pedal position sensor harness. Called JMS and they're sending me a replacement. I guess the BAP being constantly on killed the relay.

 

[lshin037]

@Vikyank - I just read a thread where you had the exact same problem with the JMS unit where it's always boosting. How's your replacement holding up? I hope this is not a recurring incident.

 

[H-TownMachI]

I wonder if they have had a bad batch of BAP's lately. My neighbors BAP (which was mine that I traded him) was brand new out of the box when it had this problem. Maybe the FPDM is a bad batch? His car is a 2014.

 

[lshin037]

Has to be the BAP in my case. It was always on pumping 18v to the FPDM. Gotta give JMS some props. They overnighted the replacement. That's CUSTOMER SERVICE!

 

[Vikyank]

Mine has been working fine for a week now running E85. I still keep the spare fpdm and fuses in the car just in case. Sounds like they had a few faulty units, I'm sure they will be checking them all out now before they are shipped. Great service on their part, I commend JMS for that.

 

[lshin037]

Just replaced it and everything is working fine. I guess it's one more thing to keep an eye out for.

Thanks to everyone in this thread that helped me out. Hopefully this thread will help somebody else out in the future.

 

[gqneon]

Jumpstarting this thread for your input. I installed a JMS FuelMax BAP and have a couple questions since you guys have already been down this road.

1. Did you just replace the 30A fuse under the hood (the funny looking clear windowed one from Ford) with a direct replacement 30A fuse? Or did you go with a different amperage?

2. Do you run your stock pumps at 18v all the time without issue? Because I'm considering setting mine to 18v all the time and want to know if that will fry it or kill the service life.

I would think tuning would be a lot simpler with a flat input voltage to the pump instead of 2 different step up intervals, but I want to make sure it's not a really bad idea.

 

[lshin037]

Replaced with the fuse that came with the kit. I think the original fuse was 25A. I run mine with an accelerator position sensor so it only activates at WOT. I fried my FDPM when the BAP was malfunctioning, causing the BAP to be activated all the time. But some members have been running non-programmable BAPs with no issues.

 

[gqneon]

Gotcha - thanks! I'm gonna let Lund do his magic, but I'm thinking i might need to run this BAP 18v all the time!

 

[bobster]

Had this exact thing happen to me a few days ago but I jumped the gun and replaced the fuel pump so I now have a spare, my FPDM should be here this week and keeping a spare just in case!