1996 F150 5.0

Having issues on initial start up. When I got the truck it would start first crank every time. Literally a turn of the key for a second and the truck used to start. For the last 6 months I have been having to turn it over for 4-5 seconds on a cold start to get engine to start. Warm start turns right over with a 1 second turn like it used to all the time.

Went through the usual suspects. Already replaced with all new parts Cap, rotor, wires, spark plugs, and coil. Cap and rotor being the only parts not motorcraft OEM. Oh and a new battery as of last month too.

What's next? No codes (OBDII so know I did not screw it up vs OBDI test I can never do right). Spark plugs that came out looked okay on the tips but for some reason had oil or unburnt fuel on the treads (PO did not use anti-seize on spark plugs I pulled out, it was fun getting enough leverage to break them loose on each cylinder)

It does put out a puff of white smoke on start up sometimes now. It idles perfect or I would suspect IAC or TPS. If you guys think it could be those I will test them. Mileage is right at around 12 MPG before tune up and its all city driving so does not seem to be out of the norm.

And I am almost positive the starter engages every time since I can feel and hear the engine turn over when I turn the key.

 

First things first, is it a slow crank or just cranks for a long time?

 

Cranks at normal speed but takes awhile before the trucks actually starts.

 

Your gas is likely leaking down, not sure where. Try this the next time you do a cold start, turn the key on wait a couple seconds, turn the key off and back on wait a couple seconds until the hum of the fuel pump stops. Repeat this about 5 times before cranking the engine. If the engine starts quicker you will know the gas is leaking down somewhere.

 

I am confused by gas leak down? Like a lazy injector? The front fuel pump was replaced about 4000 miles ago. Does it on either tank.

 

Possibly a leaky injector or going past the fuel pressure regulator or back past the pump. Sometimes when I don't start my vehicles for a week or so I do the key trick and they seem to start quicker than they otherwise would. All I can say is give the key trick a try and see if it helps.

 

This was going to be by suggestion. Basically when it is hot and you know it will normally be a long crank, cycle the key over and over to build fuel pressure before cranking and see if it fires right up