Truck is a 92 4.9 4x4 f150 200k. A few days ago it started having a hard start issue. It will crank for 30 seconds with nothing then start bucking and sputtering you let off the starter give it gas for about 15 seconds while it tries to die the it smooths out runs fine and starts great for the rest of the day.... I replaced the fuel filter thinking it may be clogged from running to the bottom of the fuel tank (rear tank sender is out). but no change... Cleaned the air filter (it was very bad) now the truck responds very fast to acceleration but no change on the start up issue. I removed the contact for the throttle management units and cleaned the contacts still no change.
Ready for Ideas from the experts! GO:

 

Gonna toss this out there.
If you spritz starting fluid in the intake, will it start any easier/sooner?

 

Did you pull the codes?

 

I have not pulled codes the process seem intimidating anyone know of a simple walk through for it ? my CEL has always kicked on after 10 minutes

 

I found a couple good videos on youtube. A $25 code reader really simplifies it but without it is easy enough.

 

Have you tested your fuel pressure during cranking?

 

my 4.9 use to do that, as i remember it would do it off one tank but would start and idle better off the other tank. eventually the fuel pumps failed, but that wasnt for a long time, anyway it never did it after that. have you tried holding the pedal down some to keep the idle smooth and constant, that worked on mine. figured it was the AIC so i replaced it but didnt help much. on my my second pair of fuel pumps, first set i bought lasted about 80,000 miles, anyway it has started and stumbled a couple times but nothing to worry about. do you know if the pumps have been changed ?, how many miles do you have on it.

 

200k I bought the truck at 175k 2 years ago... both tanks act the same at start up. You can hear the pump prime like normal... Will pull codes in the next day our two.. How do you check fuel pressure?

 

you need a fuel pressure gauge. it will connect at the back of the manifold. youll see at plastic cap back there on the fuel line. connect it then turn the key on and check your pressure, also check it running, should also hold pressure when key is turned off. i know fuel pumps, even one of them, can cause all kinds of problems with running and starting.

 

Try cycling the key on to hear the pump run then after it stops running turn the key off. Do this three or four times before trying to start it. if it starts up easier than the check valve in the pump(s) that holds pressure after you cut the truck off are letting the fuel from the rails leak back to the tank. Its fairly common on all vehicles and the only fix is new pumps.

 

agree with the check valve problem and yes the only fix is a new pump. you really need to replace both to be safe. but first buy a gauge and check it.

 

Pulled some codes... I jumped the EEC and checked them from the CEL in the cab... First set that repeated was 553, 565, 558 Then a pause and the second set 221, 233

 

Scratch the 2nd part I redid it because I was unsure... The second repeat of code is 212 - 332

 

Upon further poking around I have discovered a length of black vaccume line that is broken off with a rubber end.. I have no Idea where it goes =