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Shawn
Shawn, ASE Certified Technician
Category: Car
Satisfied Customers: 655
Experience:  PA Certified Inspection emissions, ASE Brakes Suspension, Lead diagnostic Tech.20 years exp
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1996 gmc: water in my fuel line, missing..antifreeze..it runs good

Resolved Question:

I have a 1996 gmc sierra, 5.7 litre.It runs great until it rains or if I go to the car wash, it then runs like I''ve got water in my fuel line, missing, hesetates.Fuel line antifreeze does not seem to make a difference. Only when things drie up it runs good again?
Submitted: 8 years ago.
Category: Car
Expert:  Shawn replied 8 years ago.
Customer

Does your Sierra still have the factory spark plug wires, distributer cap and rotor on it or has it been a long time since they have been replaced?

Alot of times when you develope a miss only during wet times it is a result of the plug wires getting wet and allowing spark to jump to ground(ie: the engine). Take a spray bottle filled with water and mist over the spark plug wires along the entire length and see if it begins to miss again. If so it is time for a tune up. Plugs, wires, cap, rotor,filters(air,fuel) and a PCV valve. It would be a good time to clean the throttle bore at this time to. Should take care of your missfiring and improve fuel milage.

 

 

 

 

Shawn

Customer: replied 8 years ago.
Plugs, wires, cap, rotor,filters(air,fuel) and a PCV valve have been replaced 10,000km ago along with a fuel pump. the truck has 86,000km.
Expert:  Shawn replied 8 years ago.

Try wetting the wires anyway to see if the missing starts. There is still a chance the wires are bad. Pull the cap off and check the contacts inside for discoloration. I see many of these GM caps on the 5.7 have moisture problems turning the inside contacts a greenish blue color. Moisture builds up in the cap from plugged distributer vents in the bottom of the distributer. It definately is a moisture problem in the ignition system or possibly at the PCM connector.

 

 

 

 

Shawn

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