I have a 2006 STX with 4.6 after sitting it is hard to start, it will turnover after attempting this three to five times it will start. I had a guy check it out and said the throttle body was bad ? It is doing the same thing again after a couple days does anyone have any ideas, the fule pump appears to be working fine

 

2Guesses. 1 Fuel pump driver module. 2 Stuck open egr valve.

Have you had the fuel pressure checked?

When was the last time the fuel filter was changed?

 

Fuel filter changed about month ago, I assume the mechanic checked fuel pressure ? when they changed the throttle body, I figured the fuel pump was ok because it will start along and along with no problems, and it does start ok when it is hot

 

The fuel pump may be OK. The fuel Pump Driver Module (FPDM) may be going bad. It is located on top of the cross member above the spare tire. They can do goofy things when they start to go bad. Put FPDM in the search box and see if that looks like your issue.

Bad plugs will make it hard starting too. What does the maintenance history look like, and how many miles?

 

The plugs were changed about 8 months ago motor craft, truck has 130,000 miles

 

FPR symptoms: hard starting, occasional stall, surge in rpm or a sudden drop (near stall).

Fuel pressure regulators do go bad...also agree with jgger's ideas. Good luck!

 

Isn't there a temperature sensor that tells the PCM to enrich the fuel mixture when cold? Could this be the problem?

 

There is no FPR on a 06, it uses a FPDM instead.

No fuel pressure test port, the only way to check it is with a OBD2 scan tool.

 

Another thing it will do when turning it over you can depress the gas pedal and it will help it start up, this after noon I let it turnover until it started took about 5-8 seconds and when it starts it takes a second for it to rev up.

 

Ahhh...thanks. Was not aware.

 

Another thing it will do when turning it over you can depress the gas pedal and it will help it start up, this after noon I let it turnover until it started took about 5-8 seconds and when it starts it takes a second for it to rev up.

 

Just to let you guys know the problem was bad fuel injector on the #6 cylinder, replaced injector starts up and runs like new truck.