My 05 F350 will not start. Occasionally over the past few months while sitting at a stoplight the rpm fluctuates up and down about 100 rpms and acts if it is going to stall, also a few times at low speed in traffic it seems to momentary loose a small percentage of power.

Today for the first time, it will not start. I parked it Friday with all seeming fine. When I attempted to start it this morning, the engine acted as it was going to start for a split second. When it didn’t start, I turned the key to off then on, the fuel pump seem louder than normal and ran significantly longer, about 20 seconds before shutting off. I tried to start it again, and once again it attempted to start for a split second. I repeated this several times with the same result. I then changed the filters since it seemed the engine was not getting fuel although they only had about 6000 miles on them. I still have the same result

I think it is a bad fuel pump because with the key on, after the fuel pump shuts off, I can remove the cap on the secondary filter and it does not spray, nor does the pump kick on. Also, if I turn the key to on and let the pump run until it shuts off, I can turn the key off than immediately back to on and the fuel pump will cycle again for about 20 seconds. It does this repeated no matter home many times I cycle the key.

Opinions?

 

Not sure if you've been there yet but this is from the No Start thread in the tech folder:

17. Change both fuel filters, inspect appearance of the fuel when draining the water separator (you could just have bad fuel).
Make sure that the air is purged on start-up. By following the proper (KOEO) cycling procedure before cranking."

18. If you can, verify the fuel pressure (test port is at the base of the secondary fuel filter). Must be over 45 psig.

19. If you have no fuel flow or low pressure, it could be a bad pump (HFCM), OR it could be a plugged fuel filter or plugged lines. You can blow air through the lines to check for plugging. If there is no pluggage, test the pump. First, pull fuse 302 (PCM) and relay 304 (FICM) and then pull the secondary (upper) fuel filter, remove any fuel, and then verify that it is being filled by cranking the engine. As it is being filled, make sure there are no air bubbles. If there are, you have a leak in some connections, the HFCM suction line, or the HFCM o-ring (most likely). Be sure to lube the o-ring w/ oil before re-installing.
TO CHECK FOR SUCTION LINE PLUGGING:
The pump vacuum test is refered to as an ""inlet restriction test"". This will test from the pump to the tank for a restriction. A reading that of more than 6"" H2O vacuum is very bad. 6"" is the max limit. The normal reading is between 2"" and 0"" of H2O.
To do this test you would need to ""T"" a vacuum gauge in between the back of the pump and the line coming into it. If you have a high reading there, then move the T to the tank at the outlet line. If the restriction is still present at the tank, then the problem is in the tank. If there is no restriction at this point, then the issue would be with the supply line to the pump."

 

Changed primary and secondary filters and orings as stated above.Disconnented fuel tank supply line line from the inlet of the HFCM and since tank is nearly full and truck is on an inclined driveway, fuel was flowing freely from line so there is no blockage from the tank.
I have not checked fuel pressure since I currently don't have a gauge. What size fittings are required to check this? Also, should the fuel system maintain the minimum pressure as long a sthe key is on because like stated earlier, I can remove the cap on the secondary with the key on after I hear the pump stops running and no fuel sprays out.

 

The pump does not go off pressure. It's on a timmer. It will run for so long (20 sec) when you turn the key forward after that if you don't start the truck it will turn off. When the pump is turned off there will be no pressure at the cap. In order to see if the pump is working (which I suspect it is) pull the upper filter cap suck out the fuel that is in it, and turn the key forward while watching the bowl to see how fast it fills. Should fill very fast. 1-2 sec. There are lots of probabilities with what we have to go on right now. Start with the no-start thread in the tech folder, and go form there. If you have any questions on how to do anything in there let us know.

 

fitting size is M12x1.5. Most gauges are 1/8" NPT.

I think the pressure drops pretty quickly after pump stops. In the test above, the cap is off and the bowl is empty to start (a turkey baster or somthing similar will help) then turn on key and bowl should fill quickly, 5sec or less. Need a helper to turn key. Bubbles are a problem also.

 

Thanks guys, will give it a try this evening.

 

Forgot to add: don't forget to pull fuse/relay. Not good to buzz injectors with no fuel pressure if you don't have to.

 

Tested the fuel pump at the secondary filter. Got 50 psi so it appears the fuel pump is functioning properly. Buddy comming tomorrow with a scanner to check for codes. Hopefully something shows.

 

FICM or HPOP leak?

 

How are these determined?

 

You have to have 500 psi at the icp for the truck to start. As far as FICM you need 48 volts for main power.

 

The surging problem sounds as if it was telling you something was about to happen.I believe that's a sign of a bad icp sensor,or an ipr going bad.I can't recall which.someone here will know though.keep checking your post.it would be nice if you could read the icp psi.needs 500 to start.

 

Here is the FICM test procedure. Not too hard only takes 15-20 minutes but you could use a helper to turn the key. You will need a multimeter, digital is best:

https://www.ford-trucks.com/forums/8...procedure.html

Your ICP sensor is on the passenger side valve cover:

Originally posted by Bismic:
The ICP (Injection Control Pressure) sensor needs to read 500 psig to fire the injectors. If it fails low, you will crank but not start. By unhooking it, your computer detects that it is not present and goes to a default control strategy that should allow your truck to start if the ICP sensor is truly what has failed. If you are having problems with your LPOP (low pressure oil pump) or HPOP (high pressure oil pump), disconnecting the ICP sensor will not make any difference.

 

Thanks for all the info Rusty. We checked for codes this morning and none were detected. When I get home I am going to do the procedure on the FICM that you provided. I will let you guys know the results. Also, am I understanding correctly, that if the ICP sensor is bad, I should be able to start the truck if I disconnect it?

 

Correct.