04 f550 fuel starvation

[Pistolgrip426]

Had a issue lately where the truck runs great, starts good but at 60 mph will act like not getting fuel, ended up replacing injector 5, runs better than ever, ficm is good, getting no codes, will take off like a rocket then starve and must feather throttle, new fuel filters, removed fuel tank and inspected pickup and fixed guage at same time,new fuel lines to hfcm, fired right up, idles well, will tach up in park, no stumble going into drive, can punch her a bit,she has great power,but runs low on fuel, doesnt even run rough just go's limp, no cel, no smoke,secondary fuel bowl is near empty, is hfcm gone south ? Nuthin' else to change in supply to hfcm all new, good fresh fuel, will sit and run @idle and yard drive all day long....... Help,

[HAM_RADIO_MAN]

Do you have a metal fuel tank by chance? Also some tanks have delamanation issues. Could you pick up be getting cloged up.

DTS Articles - Fuel Tank Contamination

[Pistolgrip426]

no,like i said i just dropped the tank today and inspected the p/up,and no dirt or problems in the tank,

[HaysKSFirefighter]

Sounds like your pump is going out, you've ruled out the filters and the pickup tube being the issue..next logical step would be pump

[HAM_RADIO_MAN]

Originally Posted by Pistolgrip426

no,like i said i just dropped the tank today and inspected the p/up,and no dirt or problems in the tank,

oops , missed that part. Pluged vent, bad gas cap? ? If you have a vac pump you could see how much vac it takes to draw the fuel from the tank. I think the spec is 5 in wc I am 80% sure. Might look at fuel pressure regulator.

[Pistolgrip426]

she has a new blue spring and ran great with it installed,I have a nice snap on pressure testing guage,but can't find the fitting anywhere,even at 2 hydraulic shops,(gonna order one today),I have a new ford HFCM pump arriving this morning,yep,I checked all the free stuff by dropping the tank,pulling the sending unit, and changing lines,she runs well enough that I can't find any leaks in the system,and I am sure that the pump is the issue,just was curious to know if these things will run well 1 minute, then like crap the next with the same pump. thanks for the replies.

[dannyboy950]

If it turns out to not be a fuel delivery issue you may want to consider this.

Check your fuel system for exhaust gases blowing into the system, if it is a real small leak it would take a while to build enough pressure to force the fuel backwards in the system.

Easyest test is diable FICM and fuel pump remove filter cover and with a helper roll the engine over a few times and see if bubbles show up in the filter houseing. For a very small leak you may need to repeat the crankover several times before it may show up.
Note# do not crank for more than 30 sec. at a time.

Second test is remove the fuel feed lines to the heads at the filter houseing. Attach small ballons to each line repeat the crank procedure. If it is blowing gas it will inflate the ballon on the bad bank.

Something to think about.

[Pistolgrip426]

putting a new hfcm on today,actually got the old one disconnected,and laying on the framerail,looks like I need to drop one end of the frt. driveshaft to get it out,,geeeeeeez !,nuthin' is simple on these trux !!......lol

[dannyboy950]

Nope it's designed that way LOL it increases mman hours for the shops.

[michaelaiman]

Any Idea what killed the injector that was replaced? If the fuel o-rings looked like they were sucked outta place then fuel starvation is definately an issue. A fuel pump may perform under no load but under full load or WOT condition may not. Dynamic fuel pressure test is how you spot this. i.e. monitor your pressure goin down the road under load and WOT conditions. Hope the new HFCM worked out for you, thats an expensove guess