You have the dreaded Ford emissions computer running that carb and
timing system.

If the knock sensor has failed or any other of the hundreds of feet (it
seems) of vacuum lines have failed the computer dumps into 'limp home
mode' and clamps down on the timing.

To test for this, warm it up fully and then open the hood and give the
front tube of the intake manifold a warp with a hammer. The engine
should stumble as the knock sensor kicks the timing. If this doesn't
happen, you could have found the cause of the ping.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Kevin wrote:
>
> Thanks for everyone's informative responses. I knew there were some
> good reasons not to go to a 160 stat, it just really bugged me that the
> smog police would care about that. The only reason I believe my timing
> is on is because every mechanic / smog tech to have ever checked it is
> getting the exact same reading as I am, but I guess I should check it
> with a gauge. I have run water slowly into the carb and am on my 2nd
> tank of Chevron 91 octane gas, both have helped but it still has a way
> to go. I think I will go ahead and remove my Air Conditioning system
> since it doesn't work anymore anyway, and the condensor is right in
> front of the radiator.
> Thanks again for everyone's help.