GMC Jimmy

Gmc jimmy 1994 182,000 miles. I took it to a dealer and they could not find anything wrong (computer check, puel pump and vacuum checked). It would stall when driving normal speeds sit 10-15 min. Then start up and run fine but some days will run without dying. It will just shutdown anytime.I replaced fuel pump, filter, ign coil, dist cap, rotor, chip, battery. I cleaned cables and grounds. Also took cpi off cleaned it out and it ran fine for awile but died again after that (i did hook everything up right)now there is a small pinging noise by the intake. It must be a sensor or relay but how do I know which one without buying every sensor and part on it? Also could it be the engine ground, I found it was broke off the engine side so I grounded it to bolt on intake?Thanks
August 1, 2006.

Replace pick up coil in distributor

Aug 29, 2006.