I have a 1993 Honda Accord LX and while I am driving, it acts like it trying to pass something through the exhaust. It jerks too. But this doesn't happen all the time. But we have established there is nothing in the tank. It sometimes shuts down while driving. Our mechanic who is very experienced can't determine what is causing the problem. Is this a distributor problem? Sensor? Computer chip? I am at my wits end on this. I would appreciate any suggestions that maybe we have over looked.