Has any one tested there fuel pressure? What should be normal idle pressure for a 96 351? Mine is at about 25 and when you give it gas it drops a little. I guess my question is is it my fuel pump that is bad or my pressure regulator? How could I tell? I have a shop manuel but i want to make sure I am reading it right. It says pressure should be 35 to 40 and drop to 30 under heavy vacumm load. But it also says the regulator reduces pressure to 13 to 17. Maybe that is fuel injector pressure, not sure, any help would be great. Also when I first turn my key you hear the pump kick on but it only gives me about 5 to 8 pounds of pressure at the pressure guage

 

Might try replacing the fuel filter first off. I have to ask though....are you having any problems with your truck?! If you aren't, I would say just change the filter for maintenance, and just leave it alone. Mine is about 37psi (93 351w) at idle, and jumps to about 45 when goosed.

So, what are you problems if you have any?

Gary

 

I already changed my fuel filter.My problem is hard starting. I already replaced the coil, plugs,wires etc. It seems it is not getting enough fuel to start. It takes several tries to get it started. When it does start it runs like crap untill warmed up. I used a fuel pressure guage and it runs about 23 to 25 at idle when i give it gas pressure decreases. So if your at 37 at idle I think I got some problems.

 

 

I am currently having this problem with my F250, what did you do to fix yours.

 

Whatever he did, this thread is four years old, and he isn't going to reply.

Can you tell us about your truck, what's wrong with it, and what you've tried to do already?

And welcome to FTE!

 

Try cleaning your IAC. Do a search on this forum for the exact procedure.....its very easy, and helps with hard starts and erratic idle.
I would also pull codes.....even if the CEL is not lit you could have codes stored.

 

Won't start first time in the morning, cranks over for 20 seconds and then starts, no problems the rest of the day. Next day same thing.

 

It could be fuel pressure, but it could be a lot of other things, too. Do you have a fuel pressure gauge? If not, you can pick one up at just about any parts store.

Have you tried pulling the codes as Streetgang suggested?

 

I started having this exact problem about a month ago. The problem seemed to start right after I put a bottle of fuel system cleaner in the truck, however there is nothing unusual about that as I use the stuff about every three full tanks. My problem seems to mirror all of yours. It cranks for a long time but if I stop cranking then hit the key again it fires right up. What I've been doing lately is to turn the key on and off a couple of times to spin the pump up before starting and it starts right up. But that's just a band aid. I'd like to fix this.

So far I have replaced the fuel filter as well as the fuel pressure regulator. I can tell you that replacing the FPR made the already smooth idling truck even smoother and seemed to give it a performance gain too. The truck is in a good state of tune overall otherwise, with a clean air filter and throttle body and some newer parts like IAC and O2 sensor etc. But the hard cranking issue remains. I can also say that I have noticed this type of thing in the past but it seemed to be isolated incidents and it was not as severe. However, a couple of times, in winter, it did this and then flooded the plugs and refused to start at all. It was not exactly the same but I think that the problems are related.

I plan to put a pressure test on the truck this weekend to see what the fuel pressure is. I did not realize that this problem was so common. It's aggravating to me because the truck runs so beautifully otherwise. I'd like to get this resolved. SOMEONE must have fixed this in the past and knows what causes it. Let's figure this one out guys, put our heads together and fix it. You've seen what I have done so far and I'll report back with the fuel pressure in the next couple of days.

 

I too have replaced the fpr, and it did run smoother. I have no complaints with the performance once it starts. I cleaned the IAC out today and will see tomorrow. I also purchased a Ignition Control Module, will replace in the morning if still there. I was told it may be the check valve that is in the fuel pump, but mine has the problem with both tanks and each one would have had to go out at the same time, not likely. I had my fuel pressure checked and it was OK. I am at a loss. Please help

 

I am not looking at anything like the ignition module since it must be a fuel issue, considering the fact that if I turn the key a couple of times to spin the fuel pump up the truck starts right away. If it was an electrical problem then spinning up the pump to get fuel to the motor would not make any difference. There is not much to the fuel system, so I'm stumped as to why this seems to be so hard to fix. I figured that it has to be the pump, but your situation with the two tanks seems to point away from the pump. I hope that it's not the pump anyway. I do not want to have to drop the tank, actually I won't and will let a shop do it. But still, who needs the hassle...

 

I was convinced it was the fuel system, but I had a shop look through everything and no problems, I to can start mine after cycling the key a few times. It appears we have the same problem. I was told to change the ICM, but am very scepticle. This sucks

 

JBronco,

I was just told there is a good possibility it is my computer AKA PCM. I am not quite sure what the actual part is but does this sound possible.

 

I had this EXACT semptom. If you put a pressure gauge on the rail, turn the key on then off you'll see the pressure drop over time. Mine went this way for two years before I got the motivation to fix it. By that time the pressure would bleed off in a matter of seconds.

The Fix: Fuel pump.