I hate to ask this again, but was this happening before you tuned it up? Fuel problems and ignition problems mimic each other. If this is fuel related, it most likely is a lean mixture caused by a vacuum leak. If this is ignition related, it most likely would be a timing issue, but could be other things. In the process of what was done, the distributor could have been moved, or possibly the vacuum advance line was damaged/disconnected. From this distance that is only a guess.
Paul W.
-----Original Message-----
From: jhplc@xxxxxxxxxxx
To: mailing-list@xxxxxxxxxxxxxxxx
Sent: Thu, 25 May 2006 10:57:27 +0000
Subject: IML: 73 now runs..(but)
Thanks for the responses, list!..and now..
The plug wires are now in the right place on the cap,
but , after about 10-15 minutes of driving, it backfires under
acceleration, especially when going uphill..(it idles ok)..
Could it be the fuel pump needs replaced, or the heat riser is
stuck?..thanks
Jerry