Hey guys I changed the spark plug, wires, cap and rotor and the truck still has a miss and no power, what else could it be?

Got the truck from my father in law, he said it was a 5.2L but he doesn't know anything about cars. The VIN says its a 5.9L is there any way to tell by looking at the engine? There are no stickers under the hood or on the coresupport.

Thanks

 

It's hard to tell from the somewhat vague "miss" description but if it only misses occasionaly, ie not every second crank rotation, I would be looking at timing....CPS, timing chain etc. However if it is every second crank rotation I'd probably suspect one or more of the piston locations not firing due to things like bad valve or bad electricals, bad injector etc.

 

The miss is not all the time, when it does the rpms drop a few hundered and then comes back up. That is driving normal.

What is CPS?

The no power I talk about is when I press the gas pedel to the floor the motor acts the same as if I was just taking off from a stop like normal driving. Engine does not rev faster and has no get up and go. I need a couple of miles just to pass someone...lol

Oh the truck has 190,000 miles on it.

Thanks for any help

 

CPS is crank position sensor.

hmmm. Now it kind of sounds to me like something else than what I was thinking. Fuel pressure also comes to mind. Do you get any check engine light?

 

No check engine light, I checked it any and it came back with 55.

 

It's hard to prove in the shop if you don't have a dyno and you don't have a fuel pressure gauge in the cab to watch either....maybe you can tell where my mind is going. You may need a new fuel pump. Have you changed your fuel filter lately?

 

I got it from my father in law about a month ago, before he gave it to me it was sitting in his backyard for about year.