I'm back. Ive posted similar to this thread before, but thought I'd give it a refresh. I had bought a new 2010 f250 but she was written off a couple weeks ago. So I'm back building my 4.9 for Winter, as planned anyways. I need some help! Pretty thourough this time around, so hopefully anyone can help pinpoint an issue.

Hey everybody new to this forum here. Haven't had any luck with anybody being able to help me with the issue I seem to be having. Here's what's going on.

The truck runs great once it's up and running. The trouble is it's having a rough time turning over when it's cold. It'll crank and crank and the I'll have to shut the key off, turn it back on and turn it over. It'll fire up and sputter until i pump the gas then she goes good. Yes I know it seems like a fuel issue. But here's what's funny.

REPLACED PARTS:
Fuel Pump
Fuel Filter
Fuel Pressure Regulator (38-40psi constant)
Ignition Module
Plugs and Wires
Distributor
Cleaned Throttle Bodies

Swapped out TPS and IAC from another running vehicle

This is what I CAN remember replacing, haha. I used to have a 2010 F250, and recently was written off so I'm getting the old trustworthy truck going again. I can drive it, but I need it to be fixed as it's a sledding truck and snow's almost here. Hopefully someone out there can help me. It's bizzare how I haven't tracked the issue down and very frustrating! Any input is appreciated.

I've also done a compression test on the motor and it's like new almost. Between 148 and 151 on all the cylinders, unreal!!!

Thanks everybody!

 

fuel pressure seems low for a 4.9 should be more in the 50-60 range i think

 

fuel pressure.

 

Fuel psi is low for the 4.9, as others stated.

 

So what should I be looking at? Make any difference to replace the entire sending unit with the fuel pump???

 

Do you have dual tanks? You want to check pressure for each tank. The pump / sending unit can be to blame.

 

No the truck is just a single tank. It just has the in tank pump which attatches to the sending unit then through the fuel filter to the engine. I've never replaced the sending unit always just replaced the pump itself. Would it benefit if I swapped the sending unit too? Just bought a whole pump and sending unit assembly?

She was being a miserable b**ch this morning. Cranking then it would fire sputter stall repeat.... I've also checked any possible vaccuum leaks as well as replaced the valve cover gasket and manifold gaskets.

 

sounds like wrong pump or FPR

 

Hmm, never thought of it being the wrong pump. Although the look basically the same. I know that the FPR is the right one though, as long as the guys at the auto shop didn't sell me the wrong one lol. I will look into the pump more and see if it's the right one.

 

I've finally had something happen that can lead somewhere... truck will turn over for days but now won't start at all sometimes it tries to fire but won't. Can hear the fuel pump running when I turn key on and sometimes can smell fuel after a while of trying. Ignition related????

 

Does the fuel pump run constantly when you turn the key on, or does the fuel pump run then shut off after a couple of seconds ????..........this is a very important question.

Bob

 

It will run for a couple seconds to pump the fuel into the lines.

 

Boy, pretty fast on the reply there !!!!!!

I'm a believer in checking the PCM for strange and unexplained problems.

Here's a little reading and what "MIGHT" be your woes.......

A9x ECM's (and same years ECM's) Failures Due to Age

Wouldn't hurt to give yours a peek just to make sure.


Bob