Hey guys,

This is my first post and I am running out of options. I recently bought a 96 F150 that started off great, however, as of recently, it hasnt been running too good. The truck has been having episodes of violent shakes when I go to start it up. The whole truck shakes, sputters, then dies out. After that I have to try a couple more times until it finally turns on. It doesnt happen every time and once its on the truck runs fine. I started by replacing the IAC valve but that didnt help. I then swapped out all of the o2 sensors and that seemed to help for a couple days but then the issue came back. The check engine light isnt on so I cant pull any codes. If any one out there has any advice of where to go next I would GREATLY appreciate it!

Thanks

 

Fuel presure / pressure regulator (too much fuel flooding cylinders)
Coolant leak into a cylinder (runs fine after coolant is expelled from cylinder)
Spark plugs (would be more constant poor performance)
Wires (would be more constant poor performance)

 

What motor?

 

Thanks for the reply 16IngotFX4. Spark plugs and wires were replaced before I bought the truck and Ive only had it for about 4 months but I checked them and they dont look bad. Im not a mechanic but im guessing the fuel pressure/pressure regulator be a fuel pump issue but how would I check that?

 

white89gt the engine is a 4.9 i6

 

96onefifty, I'm not a tech either and so I can only offer very general advice, but from what you have described I am inclined to think you have a fuel pump problem. My '99 4.2l started having intermittent no-start problems. Every so often it just wouldn't fire. A couple of hours later it would start and run just fine. You have said that yours does start, runs violently, and then dies out. Again, I'm not an expert but I wonder if you're not getting some fuel into the cylinders at first, and then the fuel pump dies and it stalls. An intermittent condition, just like mine. Eventually, one day at the grocery store mine just wouldn't start for hours and I had to have it towed to a garage. It was the fuel pump that needed to be replaced. In terms of testing, I think you can use a fuel pressure tester, but bear in mind that with an intermittent problem the pressure might be just fine when you do the test. Good luck with it.

 

The 4.9 timing was gear driven direct drive and known for gear and timing problems.

 

16IngotFX4 thanks man. I drive it daily so I’m crossing my fingers that I fix the problem before I get stuck somewhere too. I’ll look into the fuel pump but do you think the fuel filter might be a possibility?

 

River1 how would I go about testing the timing?

 

I have a Bluetooth obd2 scanner


and got some readings but I’m not really sure what the “normal” readings are suppose to be