1990 Chevrolet Blazer Q&A
1990 Chevrolet Blazer Question: What would cause the engine to surge randomly, especially when driving uphill?
The vehicle is actually a 1983 K-5 full size civilian diesel Blazer with a take-out 1984 military 6.2l J code diesel engine with original military DB-2 injector pump that has a slight fuel leak at the throttle shaft, "new timing chain, and head gaskets installed during engine swap two years ago", 4X4, 700R4 trans. The engine acts like the timing is increasing during the surge with more engine rattle, and speed. The truck has a slight vibration at idle in both park and drive gear, white smoke from passenger side exhaust for 10 seconds after startup but no smoke from drivers side, and #4 cylinder has lower compression (250 psi) than the others(around 300 psi). Other than that, it runs very good for a normally aspirated diesel engine. I cleaned all 8 injectors manually DIY. When I turn the engine over by hand I can hear a clicking sound coming from the passenger side of the engine. Since the injector timing is regulated by the fuel pressure inside the injector pump, the throttle shaft leak might be the cause is my guess. All help is appreciated! - lightsaber
surging could be several things but fuel leak would be where i would start,also ck fuel pressure at lift pump - globalhelper