1999 B3000 - Slight Jerking While Driving
 

As the title says, it doesn't do it on acceleration, deceleration or traveling down hill.
I'll give some history first, I've had it for about 3 weeks now _ bought it from a private garage who was selling it for the owner _ the owner left it sitting for 8 years with fuel in it. :boggled:

The garage cleaned out the tank, installed a new fuel pump and generally cleaned out the fuel delivery system of the 8 year old fuel.

It ran, but not well _ lack of power _ pinging, but did idle and start OK.

After doing allot of reading and taking it to a trusted private mechanic with his code reader, the following was done.

Cleaned the MAF sensor and related connections (it was very dirty). That pretty much cured the pinging and power problem, but still had codes for "PCM" "EVAP" Camshaft Sync sensor" and "left bank Oxygen sensor"

The synchronizer was good ( someone I sure replaced it at one time), but it was put in wrong.
I bought a new cam positioning sensor from Ford and they even let me take the synchronizer tool home over night to get it right.
The synchronizer was out more then 90 degrees with number one on compression at TDC !:hypnotize

It runs pretty good now except for the slight jerking while just driving down the road _ I can even feel it at high way speeds, but just barely because the truck is going too fast to really notice.
It feels like a bad plug, points and/or coil if it were an old fashioned carbureted engine, but if there was a problem with the ignition I would think that under load or hard acceleration it would miss.
The truck pulls really well when going through all the gears (it's a standard) revving up to 4000 rpm each time.

I cleaned the grounds and the rest of the connections on all the engine sensors including the PCM.

I reset the PCM by disconnecting the battery and draining the capacitors by connecting the positive and negative terminals together.

This seemed to have taken care of the rest of the codes and the "Check Engine" light is remaining off.
I am assuming that the PCM and related ground connections were dirty like the MAF sensor was, so I was getting a false positive check engine light.

The only thing left is the slight lurching/jerking while poodeling at 30 to 40 MPH or slower. (it's very annoying...)

I'm thinking that the IAC valve is dirty and sticking _ the PCM is trying to close it and it can't because it's dirty.
It looked quite sooty when I cleaned the throttle body (it was pretty carboned up)

I say it may be the IAC valve because the idle seems a bit high at just below 1000rpm and it doesn't always return to that _ I have to touch my foot on the accelerator peddle to get the idle to slow and even then it just goes above 1000 rpm.

The engine light doesn't come on, but it may not if the valve is just dirty.

Any opinions and help on this would be much appreciated ! Thanks !