With compression that high it seems to me that it would be unlikely the timing chain is off a notch. The valve timing would have to affect the compression. Those compression readings seem high if anything.

 

Yeah....based on what I read I was expecting 140's. I was surprised at 190's. Regardless, the good thing is that I they were all within 15% of each other.

I am stumped. It'll cost me a chunk of change to put this truck on a boat and ship it to Nassau. I might just put the chain in to see what happen.

With all the new parts most of the time it starts on the first try and purrs like a kitten......until you put it gear.

Before I read how to properly check the compression I took a plug out, screwed in the compression tester, and started the truck. That reading was 150ish psi. The odd thing was that you couldn't tell the motor was running short one cylinder.

 

Well, I suppose at 270k miles it could use a new timing chain anyhow......

Keep in mind. The advice is free and may be worth exactly what you are paying for it.

 

Finally....figured it out! But I still need a bit of help. My mechanic took the motor down to the timing chain and it did not jump a link HOWEVER.....He found the problem while he was there. He said the pin on the "Damper Pulley" was sheered that's why the timing was retarded....had something to do with sending the signal....er.....something like that. I ran a search on Google and Amazon for the part and got no results. Does anyone know the proper name for that part so I can get it ordered?

Ya learn something new everyday.

 

Well, that engine uses a camshaft position sensor and a crankshaft position sensor.

Do you have a shop manual for the truck? If not, you should order one, it will help identify everything. Do you have a computer with a DVD drive?

http://www.ebay.com/itm/1996-1999-Ford-Complete-Factory-Wiring-Diagram-Manual-Repair-Manual-OEM-/171593554428?fits=Year%3A1998%7CMake%3AFord%7CModel%3AF-150

 

I on an island in the Bahamas so I have limited resources. You should see my mechanics garage. It's basically a cement pad with a termite infested plywood roof. I'll drive down and take a pic. I think he's talking about a harmonic balancer, crankshaft pulley/damper ting'um and that square pin that locks it to the crankshaft. That what Bahamians call ereryting..... a ting'um.

 

Harmonic Balancer....you can see where the pin has been slipping and wearing. What do you call that pin?

Crazy....another piece of useless information I'll never use again.

 

That ting'um's called a crankshaft key ( a.k.a 'Woodruff key' )

And - thanks fer the sig quote!

 

I really hope that me reading this will help me out. My 1999 f 150 with a 4.2 is doing the same thing. I have changed many parts and I really hope that I can jump to this problem and it be fixed because it was starting to get expensive. Any word after you fixed that was actually what it was.

 

The sheered pin in the harmonic balancer was the problem. Runs like a top now!