Im still trying to determine why my truck has suddenly ceased to idle correctly.

the start:
Everything was running as normal, the truck would start and drive fine. I drove about 1 hour on the interstate, and upon pulling off the highway onto the exit ramp, the truck stalled. In order to keep it running in OR out of gear, i had to apply throttle with my foot. I figured the idle adjustment slipped or something.

In adjusting the idle, very very small turns of the slow idle screw would cause drastic changes in the park/neutral idle speed. In order for it not to stall when in gear, the park/neutral idle needs to be near 1500 rpm. At this setting, the truck will idle at about 8-900 rpm, in gear, with a/c on. It pulls very hard, and coasting around town it will pull you around at 30 mph without throttle.

Checked:
new fuel filter
new overflow valve
pre-filter cleaned
throttle linkage is nearly new
throttle cable is nearly new
air filter is clean
fuel lines are all fine

I bought the truck used, and it had governor springs installed when i bought it. I loosened them both 1 click, and it has made no difference. However, when i was fishing around in the injection pump, i found this hanging out in there:
http://brentroad.com/photo_photo.asp...1&photo=430498

Its a small set screw, and its quite chewed up. There was also a lock washer similar to the ones on my AFC housing floating around in there.

Any ideas what the set screw could be for? Could it cause this strange idle?

Other than that, i need to have my fuel pressure and timing checked. I cant think of anything else, other than a new pump.
thanks- Grant

 

I don't recognize the screw in it's present state but it could be the governor arm adjustment screw. But I do know that people who have run their engines with lost parts inside the housing have had to have the injection pumps professionally rebuilt.

 

are you sure its a set screw, it looks like the bottom end of one of the screws that holds the afc on.

 

its not an afc screw. Infidel hit it on the head- the adjustment screw for the governor lever is definatly MIA.

Ill let you know how things turn out when i get it back together.

 

Well, if it's the set screw, there is probably also a nut loose in there somewhere.

That was my guess earlier, but it looked kinda short to me.

 

Ohhh **** Grant... You unlucky SOB...

Wait - didn't you recently adjust the gov. arm?

 

Heres an update:

I found a new set screw and a jam nut, and through the help of my roomate we managed to get the new gov. arm set screw and jam nut back in there (this was NOT easy with the pump in the truck. Never, ever remove it.)

No difference. I think my fuel pressure has to be off, other than that ive exhausted every idea.


<disdain>

 

Take my word for it, when loose parts fly around inside the AFC things get bent, pump needs to be rebuilt.