Fuel pump? FPDM? Regulator? ideas?

[El Ricko]

I have this problem that developed, listen to both sound clip (30 seconds each),



first from the engine bay



(the link is at the end of this first post)



You hear the idle is not regular, it want to stall and come back regularly.



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Now listen at the sound near the gas tank



(link is in my reply. Didn't figured out how to put my links here between my text)



I hear a kind of "pshhht" every 4 seconds or so, right at the time the engine want to stall.



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A little history about the problem.



First show 2 weeks ago, sometimes starting the truck it would stall right there, and idle strange like this at the second start, then settles after 10-15 seconds and the engine run perfectly fine after that. It lasted 2-3 days then disapeared, so i thought water in gas or something.



Now today it begin to idle strange like this after 5 minutes warmup, then do it always, when i drive also. It cause the truck to jerk forward when power come back, and then die, etc. It also do it in neutral, when i rev the engine at says 2000rpm, it cut and come back like this.



So now it's undrivable safely like that.



But i'm a little lost where to search. Such a regular sound tell me it's electronic ? How is the fuel pressure regulator on those truck? Electronic or mechanic? In the tank or somewhere else?



No check engine light, can i still pull some code even if the CEL never lit (yet) ?



Truck have 62 000 miles, just out of warranty. I bought it last summer so unsure or what have been done and not mechanicaly.



Thanks for your help!

 

[El Ricko]

Ok found this for the link, the previous one is the sound in the engine bay.



The second one here down is the sound from near the fuel tank...

 

[A1cntrler]

V6 or V8?



The second video just sounds like the fuel pump turning on and off. Especially at idle, it only comes on long enough to pressurize the fuel rail and cycles on and off.



The first video, I think the sound I could hear was just the injectors pulsing. They are pretty loud on mine too.



Might try a fuel filter first off to see if that solves the problem.

 

[EddieS'04]

I thought the pumps were varible speed. sounds as if it is cycling alot.

Ditto on fuel filter, first.

 

[El Ricko]

Forgot to say it's a V8.



Yeah the first sound clip we hear the injectors pulsing. But it was to show the irregular idle. Don't focus on the injectors



If the fuel filter was bad enough to cause that... it would not be intermitent ?



And it's doing that only after idling for 5 minutes now ?

 

[scott degroot]

The fuel pump sound is not right. They are variable speed and controlled by a Fuel Pump Driver Module that receives a signal from the pcm. The FPDM pulses the ground circuit of the fuel pump to increase or decrease the speed of the fuel pump to maintain proper system fuel pressure. WIthout a scanner to see what the fuel rail pressure sensor is reading and to see what percentage the pcm is commanding the FPDM to operate at any attempt at a fix is just a wild guess at this point. The fuel rail pressure sensor is a common failure item and would be the only item I would replace without a proper diagnosis as the cost of the other components gets expensive really quick. With that said I think you have a fuel pump going bad. What you are hearing at the tank is the pump stalling and turning back on, as the pump begins to stall fuel pressure decreases, the fuel rail pressure sensor sees the decrease in pressure and relays the info to the pcm. The pcm then tells the FPDM to turn on 100% to raise the fuel pressure, when the FPDM increases the duty cycle at the fuel pump the pump gets jump started and that is the noise you are hearing. OF COURSE THIS IS ALL JUST A GUESS without looking at the scan data and doing a little quick testing.

 

[J Krogstad]

Ricko,

not sure what part of the rust belt you live in, or even if you do, but i swapped out a fuel pump for a similar issue but it ended up being an intermitten fuel pump module. the salt had rotted out the back of the it, allowing water to short out the board. The module, even know a pain to get to above the spare tire, still cheaper and easier than a pump.

 

[scott degroot]

Krogs



How much money do you think you would have saved by having it properly diagnosed fromt he get go?? Not implying anything just asking....

 

[El Ricko]

FPDM and FPS sound like 2 great ideas.



I'll have my hands on a bluetooth obd2 this afternoon to scan, i'll come back with the results.

 

[Gavin Allan]

Agree- skilled technician with the proper tools would be very helpful.

 

[swshawaii]

I'll have my hands on a bluetooth obd2 this afternoon to scan, i'll come back with the results.

Should have been your FIRST step. Surprising how many continue to guess until they read for codes.

 

[Travis Stevens]

if you dont have an dbdII port scanner just go to an auto parts store... usually they do it for free... i know advance auto, auto zone and napa dont charge... around me atleast

 

[El Ricko]

Yeah i know, but i didn't had a scanner yesterday and thought maybe someone had this problem before or could tell by the sound what it is.



Anyway got a scan and the result is P1237



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P1237=Fuel Pump Secondary Circuit (Fuel Pump Driver Module)



Electronic Returnless Fuel Systems (ERFS) utilize a Fuel Pump Driver Module (FPDM) to control fuel pressure. The PCM uses a Fuel Rail Pressure Sensor (FRP) for feedback. The PCM outputs a duty cycle to the FPDM to maintain the desired fuel rail pressure. During normal operation, the PCM will output a FP duty cycle from 5% to 51%. The FPDM will run the fuel pump at twice this duty cycle, e.g. if the PCM outputs a 42% duty cycle, the FPDM will run the fuel pump at 84%. If the PCM outputs a 75% duty cycle, the FPDM will turn off the fuel pump.



If the FPDM does not out any diagnostic signal, (0 or 100% duty cycle), the PCM sets a P1233 DTC. This DTC is set if the FPDM loses power. This can also occur if the Inertia Fuel Switch is tripped.



If the FPDM outputs a 25% duty cycle, it means that the fuel pump control duty cycle is out of range. This may occurs if the FPDM does not receive a valid control duty cycle signal from the PCM. The FPDM will default to 100% duty cycle on the fuel pump control output. The PCM sets a P1235 DTC.



If the FPDM outputs a 75% duty cycle, it means that the FPDM has detected an open or short on the fuel pump control circuit. The PCM sets a P1237 DTC.



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Unfortunately, it don't want to reproduce the problem right now, so i can't see what's going on with the fuel pressure sensor. But my friend loan me his bluetooth scanner so if it's doing it again i'll be able to see what happen.



So i will begin by changing the FPDM, it's inexpensive and easy to do. I wanted to do it as preventive maintenance anyway since i have read about that problem. If it ends up it's something else, i will have the peace of mind of this piece changed, and will keep the old one as a spare.



Will report back.

 

[J Krogstad]

l1tech,

Well when your truck is dead in the water on the side of the road the day sandy hits, and there isn't a ford dealer around that?s got power. But you yourself, has a lift and some would call the proper tools, sometimes ya find out, you were just wrong. The only code it threw was P0191, with no Schrader valve on the fuel rail to verify the pressure, and by the next morning the module with the big gapping rotted out hole in the back side that you couldn?t see had dried off and was putting out voltage, with the vm providing the ground. With 110K on a 07 trac isn?t that hard to believe it might be the pump. So in the end yeah I might of spent and extra 275 on the oem pump, but it was up and running in two days.

 

[scott degroot]

Krogs,



It was just a question. I honestly wasn't trying to imply anything by it

 

[El Ricko]

Well that was it. Replaced FPDM, it's worst looking than the more rusted ones i have seen in pictures. Surprised it didn't failed a long time ago.



Yesterday the truck quit starting completely so i had to fix it laying down on the snow in my driveway but it's not a long job!



Thanks for your help and infos!

 

[El Ricko]

Well that was it. Replaced FPDM, it's worst looking than the more rusted ones i have seen in pictures. Surprised it didn't failed a long time ago.



Yesterday the truck quit starting completely so i had to fix it laying down on the snow in my driveway but it's not a long job!



Thanks for your help and infos!

 

[Gavin Allan]

Built with pride in the USA!



That is crazy that those things rust out like that. Seems a TSB or recall might be in order.

 

[Halefury]

Got the P1237 changed the Fuel Pump Driver Module, Fuel Pump Relay and New Delphi Fuel Pump. Reset the Codes then drove a short while and P1237 showed up again. Trac runs fine tho no stalling and Acceleration is Excellent ... . Checked the wiring and no frays or corrosion. Running out of Ideas of what could be the cause of the Code coming back.