I set the timing with spout off to 10btdc

reconnected spout and it didn't chang4e what the timing light showed.

Didn't really care because it ran.

Cruising at 55, slight accel and it pings like its going to hurt itself.

back off, hold steady at 55 for a few seconds and accelerate again and NO ping, hard romp up to 70.

Kinda does the same thing from a dead start. Can never really tell when it's going to ping.

If it was a regular distributor, I would guess a sticky vac advance plate or diaphragm, but this is a fancy computer controlled fuel injected model.\\What am I missing?

Thanks

 

What condition are the plugs in? Wires? Cap? Rotor?

Is the timing staying at 10 BTDC after you drive a while? the distributor isnt lose, is it? Does it ping if you drive it without the spout connector plunged in?

See what you find and hopefully this will bump the post and someone will know more about what could be causing it.

 

new cap wires, plugs and rotor but you got me thinking...it MAY be cross talk between the plug wires, eh?

I've seen some posts about how critical some of these trucks are with respect to routing plug wires, but I don't remember exactly where I saw that topic.

This thing starts, runs and shifts PERfectly, other than that random ping thing.

Thanks

 

on the distributor the pin that holds the gear on can sometimes shear off and your gear will slip on the shaft witch will change your timing !

 

I set the timing with spout off to 10btdc

reconnected spout and it didn't chang4e what the timing light showed

Sounds like a intermittent connection in the spout circuit, timing should have jumped up a few degrees right when you pushed the spout jumper back in place while idling, sounds like you know that.

Did you check it for codes?

Get "212" "219" CM code? or 213 KOER code? just to pick a choice few.

 

My 90' 5.0 had a similar issue, turns out the engine wiring was bad, before 1992, the spout and ignition module was on the dist. itself. once i changed that, she was good as could be.