My truck is a 1996 f150, auto, 4x4, 5.0L, 116,000 miles, dual gas tanks, and i did the timing bump about 6,000 miles ago with the msd blaster coil, taylor wires and regular copper core plugs. last evening i started my truck when it the engine was warm but not operating temp and it took about a second longer to start than usual but barely noticeable. i went to pull out the drive and when i stopped at the end of the drive the truck sputtered and died. i started it back up and i felt a slight misfire. when i got home the idle seemed just a little rougher but not bad. 30 mins later i started the truck again to leave and it still started a little differently than usual. just a slight hesitation. later that night i was leaving my girl friends house and it took two minutes to get it to start. at first it just spun with no sign of any spark. then a minute later it barely fired and quickly sputtered and died. after doing this about 6 or 7 times it finally fired and ran strong. once it fires you cant tell anything was wrong. no misfires or anything. while driving down the road, accelerating, slowing down or cruising it runs perfectly fine. this morning it took another couple minutes to start. same exact symptoms as last night. but this time when it fired i hit the gas which made it sputter, i let off and it ran fine and then hit the gas again and it sputtered a little but recovered fine. I again stepped on the gas and it didnt sputter this time. it never misses or loses power while accelerating either. the last time something like this happened was with my old plug wires, they were arcing and i wasnt getting a spark, it was very damp out at the time. but now i have brand new wires that are only 4 or 5 months old. what is your guys opinion? i looked for arcs under the hood at night but this was once it was already started and running and i couldnt see any sparks. ill try to look again during a cold start. is the blaster coil too much for the wires i have? i dont think they are the good kind of wires. it is more humid here now which would cause more moisture. There arent any codes thrown yet and i have checked for vacuum leaks. I have replaced the fuel filter and the air filter is still in good condition. Now it takes as long as ten minutes of cranking over to get it to start. I never see any symptoms at high rpms (1500-2500) and it doesnt miss or lose power while accelerating. you can hear the fuel pump as you normally do when turning the key to the on position. after 5 minutes of trying you can smell a little bit of gas outside the truck but not a very strong smell. The starter only cranks the engine at 200 rpm and when the truck is idling at 500 rpm it stumbles a little sometimes but you cant notice anything at any other rpm. again the truck starts much faster when warm. if any one knows of any good tests i can perform please tell me. sorry for the book

thanks,
dillon

 

Problem:

-Cranks but wont start. Usually takes 10 minutes to finally start when engine is cold.
-Sometimes it will fire on a couple cylinders after turning key from start back to on position.
-Can smell a little gas after cranking for a while.
-Once it finally starts it stumbles quit a bit idling for the first couple minutes.
-Starts after 4 seconds of cranking when engine is warm.
-Idles a little rough.
-Runs great after it gets started besides lower RPM's (less than 1000)
-Doesnt hesitate when accelerating

Changed:

-Fuel Filter
-Air filter is still good
-new wires, plugs, coil (timing bump)


Things i've looked for:

- Arcing at night when running, cant find any arcing
-vacuum leaks, havent found any yet
-replaced fuel filter



This may be a little easier to read than first post

 

Fuel pressure regulator
Fuel Pump Weak

 

Thanks i really appreciate your response. I think i will look at the regulator first since that costs a lot less than the pump. Any way to test this or just need to replace it?

 

There should be a shradder valve (like whats on your tires) on the fuel rail. Hook up a pressure gauge and have a friend try to start the motor while you watch the gauge. you should see a relatively constant pressure on the fuel rail. If its a low pressure then you may have a weak pump. If the pressure jumps around a lot then the regulator may be bad. Hope this helps

 

Awesome! Thats exactly what i needed to know. Thanks! one more question. What brands of Fuel Pressure Valves and Fuel Pumps should i be looking at if i need to buy one of those?

 

What pressure would be considered a low pressure that would point to a weak fuel pump? Or what is the normal fuel pressure range?

 

Alright I rented a fuel pressure test kit and I just got done testing it. The book said that the normal pressure should be between 28 and 45 and i got a reading of 30 to 32 so im taking that as the fuel pump is fine and is sending enough pressure through the lines. I was looking to see if the pressure jumped around sporadically and it did not at all. The pressure rose steadily and stayed right at 30. Last night i spent 15 minutes turning the engine over to try and start it and i got nothing close to starting. Now this morning while testing the pressure my truck started after the second time of turning it over. Do you guys think that the pressure tester helped it start somehow? i kept the tester on there while it was running and checked it a few times and it stayed at a constant 30 lbs the whole time. im waiting for the engine to cool completely again and will see if it starts again.

 

I just went out and tried starting the truck again. Its been a few hours since it was last started so that should have been enough time for it to cool down. I turned the key and it started but it took about a second longer than usual. also when it first started it ran rough for barely half a second but idled really nice after and seems like its running strong. it also just rained so its really damp out which hopefully rules out the spark plug wires arcing. Its still not 100% when starting so if anyone else has any ideas of things to check id really appreciate it. thanks for all your help

 

Clean the IAC. Take the ICM in and have it tested. Still could be plug wires you need to try to start it at night with the hood open. Then you will find arcing wires and what not.