I've searched the archives, and will continue to search more, but being new to Fords I thought I'd post.

I've got a 1989 4.9L six cylinder, 133k miles that pings under load when going up hills. Very typical pinging; stops pinging if I lift off the gas or downshift (5 speed), pings less if I use premium, doesn't respond to changes in ignition timing. I've replaced the plugs, cap and rotor, fuel filter, checked that the fuel pumps both run, tried running with and without oxygen sensor signal; it still pings.

I read the codes, and I get KOEO #67, Continous #18, #95, could not get the running codes to read other than the #3 code for a six cylinder. After clearing the codes and driving the truck up a hill so that it pinged I got KOEO #67 again, and Continous #11.
Here are the codes:
#11: System OK
#18: SPOUT circuit open or spark angle word failure (what is a "word"?)
or IDM circuit failure or SPOUT circuit grounded
#67: Neutral/drive switch open or A/C on (I tested with HVAC set of "off")
or Clutch switch circuit failure (but I have to push in clutch to crank)
#95: Fuel pump secondary circuit failure - PCM to ground (from setting inertial switch while changing fuel filter)

So why am I getting code #67?

I need to get rid of the pinging. Are my fuel injectors dirty and spraying a bad pattern? I replaced the #1 cylinder fuel injector after it developed a leak. The spark plugs were fairly clean after 2k miles. Most showed signs of hot and lean operation, but #1 is cleaner than the rest.
I did a compression check and found that #5 cylinder was 30 pounds below the other cylinders, and increased with addition of oil.

Is the engine running lean or is the #5 cylinder causing the pinging?

Any specific help would be appreciated.

 

did you have spout out when you did timing?

when you said did not respond to timing changes what do you mean?

 

I had the SPOUT plug out a long time ago to check timing, but the crank appears to be rotated so I couldn't get a timing reading. The SPOUT plug is plugged in, and I timed it so that it didn't ping, but over the last month its started pinging again. I've tried retarding it by bumping the distributor a tiny bit and driving, then doing same untill it runs like ****, but it still pings. I've then tried moving it the other way (advance) and the same thing.

You might say that I'm way off, but there is a "sweet spot" in the distributor position where pinging is minimal, but still present under load at highway speeds or when rolling onto the gas.

 

if you timed it with spout in is why you are pinging.

clean off balancer and mark it, remove spout and if it is not at 10 degrees reset it.

than put spout back in.

unless you do this you will never time truck accuratly.

i would also reset computer by disconnnecting battery after you read codes again.

 

Pinging is also a sign of a vacuum leak. The plastic lines, especially the white one that controls the heater door, are brittle and will crack. If your charcoal canister is next to the battery, look to see if some baterry acid ran down and ate the case away.