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View Full Version : Hesitation on light accel....ideas?



JDeere
07-20-2004, 05:17
Hi, all,

My truck (98 K1500 6.5 turbo, no performance mods) has developed a hesitation on light to moderate acceleration, as in when pulling away from a stop light, etc. It hesitates for 1 or 2 seconds, then seems to clear itself and runs normally. This only happens intermittently, and produces a sizable quantity of smoke while it's happening.

I can hear the lift pump running when I start the engine, and opening the bleed valve produces a good flow of fuel, without the truck stalling. No codes are stored in the computer, and GM replaced my IP and PMD about 20,000 miles ago. Other than the hesitation, the truck runs very well. (As an interesting note, I just returned from vacation pulling a 25' fifth wheel trailer. The hesitation never happened once while pulling the trailer some 3000 miles. Maybe just a coincidence, though..?)

Any suggestions as to what might be causing this? I'm wondering about a sticking open EGR valve, but I haven't pulled it off to check it yet. Any suggestions as to how to more accurately diagnose this would be greatly appreciated.

Thanks!! smile.gif