I have just bought this 2006 4.6l f150 4x4 supercab from my brother-in-law. I knew it had a starting problem when I bought it. He has replaced a long line of items to try to fix it but has not got there yet. could someone help me out. It will start right up after it has already been running. It is when it sits for a while that it cranks for bout 10 sec. before it starts. When it finally starts it puts out a big cloud of smoke. I have read where people do this or that but no one is doing the same thing. How can alot of people have the same problem but there is so many fixes. Can someone help me?

 

Black smoke? If so sounds like youve got some leaky injectors. You can check fuel presure and monitor it while it sits for a while. If it is bleeding way down below spec id pull the fuel rails and watch for leaky ones. Id do a fuel system cleaner we use BGs three can fuel induction service at work but ive gotten good results with lucas top engine cleaner. After running that through id replace the fuel filter and all the injectors. Hope this helps its hard to say with out more information and knowing whats already been done but if it rolled in my shop with just that to go off thats what id expect to find

 

Drop your spare tire and look at the FPDM (Fuel Pressure Driver Module), its bolted to the frame above the spare tire. Remove both mounting bolts and look at the back of the module, if its cracked or corroded in any way, replace it. Its $60 for a dorman replacement on Amazon, when they go bad they will make the truck difficult to start. A visual inspection is all thats needed to determine if they are bad, you will know it right away when you pull it off the truck.

 

thanks to bubba i will try that. also 1st truckguy, the fpdm has already been replaced. i will post everything that has been replaced as soon as i get a list from my brother-in-law. thanks again for your suggestions.

 

I'm thinking along the same line as bubba, sounds like one or more injectors are bleeding fuel pressure down and flooding the manifold with excess fuel, that will cause both symptoms, it takes longer to fire up because fuel pressure has dropped off and now you have all that excess fuel in the manifold getting sucked into the cylinders creating the smoke.

Suggest you put a fuel pressure gauge on it and start the truck and let run while you check for any external fuel leaks at the gauge itself and around the fuel rails. If you detect no external leaks, shut the engine off and watch the gauge, it may take a while or it may drop off instantly.

 

these are the parts that have been replaced on my 2006 f150 4.6L for the long cranking time. fuel pump, fpdm, fuel rail pressure sensor, throttle body, plugs, and some coil packs. still having problems with long cranking time when cold.

 

PCM reflash? Maybe your computer is messing with you