Hi all,

My vehicle is a 94 Chevrolet K1500 Blazer with SSDiesel Intake and Exhaust. It's got 264k miles on it. Recently I've been having issues with intermittent sharp brief engine drop outs at highway speed and stalling at low speeds. It's not a gradual loss of power but rather an immediate and complete power loss during the events.

The problems started a few miles after a fuel stop, so I initially thought I might have gotten some water in the fuel. But that doesn't seem consistent with the suddenness and completeness of the drop outs, and I haven't noticed any smoking or other symptoms during the events. (The vehicle has a "Water in Fuel" indication that has never illuminated; I couldn't say for sure if it's actually functional.)

The problem has become progressively worse over about 85 miles of subsequent driving. Usually the engine will start right back up if it stalls, but recently it's started to be difficult to restart at times and will run for only a second or two on the first few attempts.

I checked the ECU using GMTDScan Basic, and it isn't throwing any codes or indicating anything else obvious.

From the symptoms, I am suspecting the PMD/FSD. I know this engine had its PMD replaced once previously by a prior owner, but that was about ten years ago. The PMD is still in the original location on this truck.

Are there any other steps I can try to confirm/isolate the problem?

Thanks!