well after new pumps, new adjustable regulator, swapping out the IAC it came down to one thing. the 820ohm dropping resistor for the fuel pumps was smashed up and no good. got the new one on tonight and took it out for a run and it seems to be fine.



heres a side by side shot of the part, $29

 

Where exactly was that located? At least it was something small that malfunctioned, but thats always what causes the biggest headache.

 

its on the mounting bracket for the heat exchanger

 

Show us plz !

Thanks.

 

Here is what my resistor looks like:

https://www.f150online.com/galleries...490-150953.jpg

Here is where it's located:

https://www.f150online.com/galleries...490-150952.jpg

On the innercooler pump bracket, behind the innercooler radiator:

https://www.f150online.com/galleries...490-150951.jpg

 

Does anyone have the part number for this fuel pump resistor ?.....Thanks

 

I'm having a flashback (kinda)
Isnt this what drove Jody (I belive it was) crazy for the longest time before he found out what it was ??? I always remember one of our Brothers having the strangest Fuel issue for the longest time and in the end it ended up being
this resister, more proff there is a hell of a lot more to our Fuel System than meets the eye...

Either way GOOD SAVE 20 and WOO HOO CONGRATS for doing some serious investigating and catching the SOB

 

Well said rob, I allways put stuff like this on my faves.Juust incase! !

 

Well said rob, I allways put stuff like this on my faves.Juust incase! !

 

leaded fuel cause that?

 

I'm guessing they get overly hot for a reason, but I can't imagine it would be tied to different resistive properties of the type of gas.

I guess while my truck is in pieces, I need to take a look at mine, just to be certain.

 

F81Z-14A601-AC List is $37.47.

These resistors are sized based on the amperage draw of the two stock pumps. When you step up to 255 Walbros, the amperage is about 25% higher, consequently the resistor runs MUCH hotter. It helps to keep it clean and be sure you don't have anything down there that might restrict the airflow which keeps it cool.

Unfortunately, the resistor is doing it's thing at idle and low speeds so there can be very little airflow around it. Once you exceed ~1/2 throttle, the resistor is switched out of the circuit and the pumps run at the full 12 volts.

 

What happens if you bypass this? I am having a wierd Fuel pressure problem...

can you bypass it? will it melt anything? What if I want to run my pumps at 12V all the time? Will it hurt the pumps? Just curious? I think mine took a dump after I upgraded to the walbro 255's..............

 

It could overheat at idle... get an electronic fuel pump controller, like www.madenterprise.com sells, I have it, its a very good one.

 

explain this to me a little more? its adjustable?
do you remove that resitor and plug this in the place?

it lets you stage whatever voltage you want?

doesn't the pcm do this and is programable in the tune?