I have a2006 f250. Slowly it started to get hard to start. Gradually it would crank over longer for it to start running. now I have to hold down the gas half way and it cranks about 3seconds then it starts. Once its running it runs great. Once I turn it off then it is really hard to start even holding the gas down. if it sits more than a few hours after driving around it goes back to being a little easier to start. just running to the store it will take a few times at cranking it for it to run again. It started before I changed the batteries. now I have two new batteries and now I can crank it longer without killing them. Any ideas?

 

Welcome to the site..

Since you mentioned 'batteries' we know it's a 6.0..

One thing I'd want to check/prove out first is HPOP related pressure issues. They need 500+lbs of high pressure oil to fire off. Sometimes a disconnect of the IPC may help on a start, but STC, IPR related or any high pressure bleed points can affect a hot restart. Cycling the key ON a few times prior to a restart have any affect on a quicker start warmed? Checking high pressure oil specs may indicate a low cranking delivery..

 

I did replace the oil cooler recently. Could that have anything to do with that? Im not showing any oil leaks anywhere. how do I check the oil pressure?

 

Not engine oil pressure or pump (although important!)

The engine has a high pressure oil pump rear of the block (fed from the engines oil pump/circuit) that supplies the 'injector push'' or high pressure oil needed to hydraulically operate fuel spray for injection. If there's an HPOP issue and when cranked the high pressure pump can 'build' 500lbs or greater the engine won't start, or if on the 'fence' may be hard/long crank times to get it to build the needed pressure. The IPR/IPC values can be checked manually meaning gauges and/or a meter, but a scan tool that can check parameter values (PIDS) is quick and precise. If you know or have anyone with a scan tool that is PID capable,(?) diagnosing spec values is a quick way to prove out possible causes or aid in some direction.

If you don't have or know anyone with a capable scan/diagnostic reader and you have a Windows based laptop (?) available, there's a free program download called FORSCAN,, with a USB cable adapter (ELM327-20.00 or so) and the laptop you would have a very capable tool in the garage. AutoEnginuity and others at substantial cost differences.

May/may not be you issue, but a good place to look as a first step, more so if a higher mileage 6.0.. Fuel probably wouldn't be a quick restart issue, but again, good to prove what it's not before looking for what it is or could be...

 

IF you have just been into the oil cooler, then some lint or small contamination might be plugging the screen on the IPR. You can get an idea if that is happening by looking at ICP pressure, ICP volts and IPR % duty cycle data (engine parameters or PIDs).

 

Thanks Gents! I will take a look at both ideas and go from there. I will be back on and let Y'all know what I have found if anything.