i have a 1999 ford f250 superduty crew cab v10 fwd with a 40 gallon center tank. the problem i am having is that intermittenly the truck will crank over but not fire, i'll leave it for a couple hours or longer and try it again and it will start. i'm thinking it may be the fuel pump. once the truck is started it runs normal no problems. am i looking in the right area? or should i be looking at something else. i live in michigan and the temp's have been running below freezing. could i have some bad gas and should i try some dry gas additive?
Hi and Welcome to JustAnswer! My name is XXXXXX XXX I will do my best to help you with your vehicle trouble.
I think you will need to know the reason for no start, which can be fuel pressure/no spark/no injector pulse
at time of no start you will have to test and see which one is not present.
on the fuel rail you have test port with pressure relieve valve. it looks like tire valve
when you pres the valve and briefly crank you will see if presure is there
is the fuel rail the rail that delivers the fuel to the injectors?
yes
I have connected a fuel pressure tester to the port on the fuel rail. The first ime just turned the key on I got 13 pounds of pressure, then I cranked it and got 28 pounds. Then I bleed the pressure and cranked the engine and got 35 pounds. I tryed two more times and got 35 and 27 pounds of pressure. Should the pressure be constant at 35 to 40 pounds with the key on or whencranking or is the pump in failure? Could a cloged fuel filter cause this problem?
Hi, pressure has to be constant 35 to 45 psi with key on. and 28 to 45 when engine running. there is definitely a problem with fuel pump if you are having unstable pressure. But at times you have 35PSI truck should start if this is the only problem. Check if spark plugs are wet after crank but no start. that will indicate that fuel injectors are opening and fuel it sprayed. if spark is dry then fuel injector pulse must be checked. and also check for presence of spark. if you do not have spark tester, remove one plug and as it is attach to it's ign cable touch engine block or good ground with sp plug treaded part and crank the engine. observe for spark between spar plug terminals. If any of those is missing, diagnosis has to be done for missing injector pulse or no spark.
Experience: 17 YEARS HANDS ON EXPERIENCE, TRUCK&COACH TECHNICIAN LICENCE
Hi pavlin. I can here the fuel pump working and I have a consant 35 psi with the key on and 29psi when the engine does start. When it won't start I pulled the#1 and #6 spark plugs and they are both dry and iget no spark out of either one so I'm lokking at something that controls both of those. Would that be the pcm unit
PCM controls both injector pulse and spark, before replacing PCM you will need to check Camshaft and crankshaft sensors signals. you need to duplicate the problem somehow with scanner available and observe those 2 sensors signals. If signals are present then PCM is causing the problem, if no signal, replace sensor that is failing.