How to check the HFCM

strokercuban85

strokercuban85

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Jun 6, 2007
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I been having problems with my fuel pressure lately , I keep adjusting it and it keeps changing . I have noticed that after a long ride it drops and then driving in the city it goes back up . I did already changed my filter and it keeps doing it . Is there a way to check my hfcm .
 
My fuel intensifier did the same thing and it ended up being a bad regulator. Replaced under warranty with a much nicer Aeromotive unit.
 
Put the stock return line back on. And see what it does to the pressure.
 
Mine did exactly what yours is doing. The pumps do get weaker with age, but I think that it is wear in the pumping mechanism not the actual motor itself. Other than something shorting in the wiring the motor either works or not, maybe a small in-between time but that would be real quick. I tested mine(yep it is pumping)and my filters were new so not much else it could of been. Ya got the silver regulator with the blue plugs? DJ told me they were crap and thats why they switched to the Aeromotive. Warranty-called Vivian told her it was bad and they sent me the new one. Obviously that is no longer possible, but I think Summit sells them, and I think it is a marine unit and it is the same one some of the other companies include in their kit. The original was never consistent with pressure from the start, and the new one is 55psi on the dot at idle no matter what.
 
yeah mine has always given me problems to set it at the right pressure . Lately it's been really bad now in the morning when cold and the engine under pressure it jumps like kind of missfiring I think it has to do with fuel .
 
strokercuban85 said:
yeah mine has always given me problems to set it at the right pressure . Lately it's been really bad now in the morning when cold and the engine under pressure it jumps like kind of missfiring I think it has to do with fuel .
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Just as a precaution-check your boost reference line, if the diaphram is leaking or breaks a few things can happen-
1-Runaway
2-Ruin map sensor
3-Hydrolock(not likely, but possible none the less)

Mine is no longer boost referenced.
 
Boost refference is for gas motors with injectors in the intake fighting boost pressure to spray. 4000PSI of ICP will get the fuel into the cylinder you don't need to up the base fuel.
 
i have checked the boost reference and its not leaking . So if i get a new regulator i just plug the boost reference on it .
 
I did not plug mine, just ran the hose down a little way so if it ever leaks it won't make a mess. I have seen other systems and they just leave the nipple on, no plug or hose. Maybe the regulator needs it as a vent to operate properly?
 
Just a thought for ya.

I don't have any scientific proof other than making pressure at the end of the fuel rail more stable(I put a gauge at the end of passenger fuel rail), but being that the Fuel + dead ends like stock, I added check valves to mine and it seems to make a difference-smoother running. Just seemed logical because Ford did it that way. It has been that way for 6 or 7 months. Cant wait to get my Pureflow system, I hope he gets it to market soon.
 
Vizsla said:
I did not plug mine, just ran the hose down a little way so if it ever leaks it won't make a mess. I have seen other systems and they just leave the nipple on, no plug or hose. Maybe the regulator needs it as a vent to operate properly?
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that nipple is for the diaphram in the regulator, if it breaks it will leak fuel out the nipple and the hose is to make sure the fuel doesnt leak all over the motor.

i hooked the hose up when i first installed it, but it melted and i havent put a new hose back on
 
Vizsla said:
I don't have any scientific proof other than making pressure at the end of the fuel rail more stable(I put a gauge at the end of passenger fuel rail), but being that the Fuel + dead ends like stock, I added check valves to mine and it seems to make a difference-smoother running. Just seemed logical because Ford did it that way. It has been that way for 6 or 7 months. Cant wait to get my Pureflow system, I hope he gets it to market soon.
Click to expand...

The check valves are to eliminate pressure spikes back to the regulator just like the AWA fittings and check valves in the high pressure oil system. They are there for something. Or else they could have saved a little bit of money on each truck multiplied by 2 and then by a million.
 
Well I had a little too much time on my hands, and other than making 3 lines larger and allowing fuel pressure adjustment, it seemed to me that all I did was duplicate the stock system. When I get the Pureflow system I wanted to eliminate the regulator and tie the fuel rails together in back with a T or y in the line and return it from there. Would that be a good idea and should the check valves be eliminated when I do it? I was just guessing at the check valve idea and just rigged up a cheapo gauge to the back of the head, but on my truck there were some considerable fluctuations in the rail that became more stable with the valves. Also have to credit Adam's buddy Adam with planting the seed because he thought my wierd idle might have been related to my fuel setup. Sorry for heading off topic, but I have been wanting to share my valve experiment on here but was not sure if it was stupid.
 
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