Ok guys and gals I really hope you can help me. I have a 1999 Chevy Silverado 4.3l extended cab. Here is my problem when I start my truck it seems to idle fine but has I press on the gas pedal the motor shakes and bucks but while doing this I unplug the tps an it gets smooth. An when it rains the truck runs real bad like something has been getting wet but after looking I cant find anything getting wet. So if you'll have any ideas let me know. Thanks

 

Fuel pressure?

Getting wet cold be plug wires/coils

 

I have no way right now to check fuel pressure. But for plugs an wires they are new and they dont look wet.

 

Fuel Filter???????? a clogged fuel filter will cause this

 

My fuel filter is only 3 months old with probably only about 5000 miles on it. Changed spark plug wires, distributor cap, rotor, and plugs with no change. An by the way the truck was running fine until all the rain in Houston last week. "Truck was not driven in the rain only started to move it in my apartment complex." My truck does not like it when it rains......

 

Once it warms up it runs fine like there is no problems.

 

Take your distributor cap off and spray some WD-40 inside and wipe it down. This will help repel moisture buildup. Just a thought.

 

i'd try a tps. or leave it unplugged lol

 

Okay yesterday I changed the spark plug wires, distributor cap, rotor, plugs, new fuel filter, and tps an im still having the same issue this morning with the motor stumbling when I press on the gas pedal. But I have noticed one thing once the motor warms up it stops stumbling an runs fine after about 30 mins to an hour. Then I turn the motor off for at least 8 hours or so that same day an it runs fine with no stumbling until the day an it started doing it again.

 

Crank sensor........changed it on my 97 when it started doing the same thing