03 Chevy Tracker Dies When Driving Jumps Off

Mine was doing the same thing I had to clean out my breather, ran gumout in gas checked all wiring. It is better but not totally fixed. I have replaced alternator, battery, paid a diagnoistic mechanic 250.00 for a "I dont know what the problem is" of course he checked it out cold, so he drove it until he experienced this issue. I got the same answer. So if any one has a clue please fill me in. I did discover a relay (according to the owners manuel goes to the AC/PW) was defective and you must put them in insequence or the problem will persist. The relays actually operates the ignition cuz if removed the ac/pw still works but car wont start. If the componets get hot from idleing in traffic it shuts off you have to let it sit I havnt worked on cars in 25-30 years but I sure have been learning that all this high tech computer crap is overrated. Just another way for the man to drain our pockets most of the electrical stuff is worthless. The heat just from the sun will kill your electrical system cuz it all from China or Japan. My last car I drove for 30 years and could fix almost anything myself. I dont even think these so called specialist mechanics know how to fix all this new stuff. I was fianlly told to get rid of the vehicle not worth the cost to fix it. I purchased this vehicle with only 7 miles on it its paid off and I'm stubborn. I took excellent care of it. But now my investment is giving me the blues and so are all the mechanics.I've downloaded the schematics and chasing wires gotta be a short all sensors relays and fuses been checked over and again. Computer checks out good no check engine light on, but sure making me scratch ma head. Good Luck!!