I agree with the other posts, the fuel distributor is an easy/quick answer and may, or may not, be the issue. Always FULLY verify the ignition system as everyone said here. If the car is due for a tune-up, do the plugs, wires, rotor, distributor cap, and BE SURE to replace with only the precise (down to the last digit) model of spark plug and part number in your car now, don't take a Mercedes spark plug equivalent number with a 0 on the end for example or a platinum model. Mechanics jump too quickly to the fuel system. Also, if it is the original fuel pump, I'd still really suspect it. The pumps are known failure items and I don't know how your mechanic can be there 100% of the time knowing exactly when or if the fuel pump can overheat enough to lose an instant of pressure. If you end-up doing the fuel distributor, keep these things in mind: (1) the aftermarket remanufactured non-Bosch ones nowadays are good and cost only about $500 as I recall so no need for a Bosch remanufactured one. I have one in my car and it works superbly. (2) Shops like to charge some unGodly amount of shop time for the fuel distributor, like 8 hours. The fact is it's a relatively easy 1 to 1.5 hour job. I watched one mechanic charge about 5 hours for the job and double the price on the distributor. Anyway, when they do the fuel distributor if they do it, MAKE SURE they don't introduce a vacuum leak there. Lazy mechanics do not lubricate the o-ring beneath the fuel distributor and they should, and some choose not to replace the 25 cent o-ring part because I don't think it comes with the fuel distributor. So they need to make sure they have one around. Such a shame to have to babysit such straightforward jobs but having been burned on this one, you need to be very careful on the small details like that.