2002, Chevy, Suburban 1500, 4wd, 5.3L engine, 210,000 miles. Mass airflow sensor and both O2 sensors replaced last year in an effort to fix this problem. Original problem surfaced when the vehicle was shut down or running uphill and had about 1/2 tank of gas in hot weather. If stopped, the vehicle would not start until it had cooled down. Sometimes getting it onto level ground would be enough to get it running again. ( This accomplished by turning on the key and allowing the vehicle to roll back out of the parking place. ) If running down the road, getting to level ground after the stall, pulling to the shoulder and cooling the engine/waiting a few minutes and restarting the vehicle would work. This was before the above mentioned repairs.
Last weekend in 60 degree weather I was driving back from northern Michigan and as I headed up hill at 75 mph with the tank at 1/2 the vehicle did a high speed stall on me. Symptoms were: RPM showed 2000, but pushing down on the gas actually dropped the RPM no matter how feather-footed I was. This was tried several times. I turned on the 4 ways and moved toward the shoulder and at 50 mph finally got the thing to restart. The rest of the trip home was uneventful.
I had a 2001 Suburban with the same specs which did this same thing until a factory recall that got me a new fuel pump. I asked about the recall the last time my truck was in for service and they said it does not fall within the serial numbers for that recall. Fuel filter replaced about 9 months ago. Co-incidentally but not necessarily related is that my battery with less than 3 years of a 7 year warranty was draining itself in less than 2 days this last winter.
So, any suggestions? I’m stumped.