Well today was a ruff day.. On my way to work my truck felt weird, kind of hesitating uphill, jerked a few times, I floored it and it felt like it wanted to shut off, RPM's fell to like 1 or 1.5k then it raised to like 4k... A few mins later i was cruising at around 20-25 mph it started jerking, bucking, boging u name it.. Then i suddenly shut off sputtering, It would restart and fire up for about 5 secs then shut off agin.. did it numerous of times. Fuel Pump was priming. So I let it cool down then it starts up like nothing ever happened. no cel..BTW it was hot outside like 90-95F

I searched on crankshaft sensor, seems too match the syptoms.. Please help me out guys.. Thanx

 

specs on truck witch 4.0 ya got??? its prob a cranksenser are cam senser. i say do both also run a fuel pressure test

 

sounds like maybe a fuel pump or a cloged up fuel filter in side the tank. or a dirty sensor

 

Oops sorry, its a 99 4.0L OHV auto 4x4... The FP idk, i could hear it prime and the truck would start for a few seconds then started sputtering and stall... I wanna check the FP relay too, ive read that they heat up and not make good contact or somthing like that.

BTW I just started the truck a few mins ago and it runs like its suppose to, this intermmitent **** is the most annoying issues in the planet

 

actully sounds like yor fuel pump went out what your hearing is your high pressure fuel pump there are 2 pumps one is mounted on the rails and the other in the tank pull your hose off from the fuel filter turn the key on and sey if any gas shoots out if its a little its a pump or filter if its alot then every thing is good

 

2 pumps?? I dont think so.. But ill check it out tomorrow

 

I could be mistaken but I do believe there is only one fuel pump

 

Older vehicles had 2 pumps... correct me if im wrong

 

What looks like a fuel pump on the rail is a fuel pressure regulator.
These trucks only have one pump , in the tank.
With the key on and engine off , pull the vacuum line off the regulator. If fuel comes out where the line connects , you have a hole in the diaphram in the regulator.

 

I drove it today.. runs normal.. but has a stinch, like unburned fuel odor in the engine area. And still no CEL

 

***Update***

Well I gutted the cats today, the difference was amazing! I drove it today to the same distance i was stranded and the temperaturre was pretty much the same.. didnt have trouble with it, no bucking no hesitating, no PINGING!! Ill keep yall updated if anytthing happens.. hope not!

 

Something tells me you only fixed the symptom and not the problem.
What caused the cat to plug up ?

 

That idk^ lol... I dont know if they were clogging up since i bought it, I just notice lack of power.

 

i had a problem where i would loose all power i could put it to the floor and only make it to a top speed of around 20mph and after 5mins of sitting with the motor off it would start of and drive fine for about 10-15mins.my truck never shut off on me,but i ended up changer the o2 censor and fuel filter and it fixed my problem

 

Yeah these are some tricky lil problems..I need to change out the upper intake o-rings, I can hear a hiss when slightly pressing the throttle. Which explains the 701&704 codes I get somtimes


Im learning, im learning...lol