I would agree that either the timing chain is loose, or the bushings in the distributor are worn. Also, check the counterweights in the distributor for wear on their pivots. --Brooks in Dallas -----Original Message----- From: mailing-list-owner@xxxxxxxxxxxxxxxx [mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of DR CHALLENGER Sent: Thursday, September 08, 2005 11:56 AM To: mailing-list@xxxxxxxxxxxxxxxx Subject: RE: IML: 71 carb problem sounds like a bad timing chain. >From: Bruce Stubblefield <audiblefeast@xxxxxxxxx> >\>Hello list, > The mighty 71 four-door (440) refuses to bend to >repair attempts. The shop and I have spent a lot of >time on this, but no soap. The mechanic I'm using is >an older guy who is quite familiar with old >carburetted cars. Though clearly not a brilliant >diagnostician, he's solved a number of other problems >on the car. > The symptoms: From a standing start or from >coasting at 0 to about 5 mph, flooring the accelerator >results in "backfire" popping out the top of the carb, >stalling or almost stalling. A slower, more gradual >acceleration does not show this problem. Also, car >surges or bucks intermittently on hard acceleration >from a stop under a load, as in accelerating up a >normal freeway onramp leading to an elevated road. > In the last month or so, new plugs, spark plug >wires and electronic distributor (mopar performance) >have all been fitted. Scopes both in shop and onboard >show normal electrical performance. Timing is >perhaps 5 or 8 degrees retarded. Aside from this >problem, runs fine on 87 octane regular. I also >frequently run 91 octane premium. > Carb (Carter, not a thermoquad) was just rebuilt, >with a new accelerator pump done twice, with no >improvement. The shop found a service bulletin in an >old 69-72 Mitchells book which described a similar >problem and gave a solution of re-boring some holes in >the carb and changing some of the metering needles. >Carb shop did this per the service bulletin, to no >effect. Mufflers and resonators are new. > Has anyone solved a problem like this? Do I >have to buy a modern carb? > ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm