99 Gmc Won't Start When Raining

[mfd1rescue]

New to forums here. But I have been reading for a long time, great info. Anyway, my buddy here at the fire house has a 99 2500 4x4 crew. He has had several people look at it because it won't start after it rains. Say they have tried everything they can think of, ie. cap and such. I told him someone on here would know. Thanks in advance for the help.

[jrrod2004]

New to forums here. But I have been reading for a long time, great info. Anyway, my buddy here at the fire house has a 99 2500 4x4 crew. He has had several people look at it because it won't start after it rains. Say they have tried everything they can think of, ie. cap and such. I told him someone on here would know. Thanks in advance for the help.

 

in his 1999 GMC 2500 4x4, what does he have, diesel or gas and does is it not start after a hard rain or light rain?

[topdj]

trade it in on a dry day:)

[jrrod2004]

trade it in on a dry day:)

 

 

HA

[mfd1rescue]

Sorry , It has a 5.7L gas. Lite or hard rain, even snow. Cranks but won't run.

trade it in on a dry day:)

 

 

 

 

 

HA

 

 

 

 

 

 

[PhilB]

When I was in college, I had a car that acted in a similar fashion. It wouldn't start after it had been raining. The problem was bad plug wires. The moisture got in to the plug wires and were shorting them out. If your friend hasn't changed the plug wires, that might be something to try.

 

Phil

[ruddy]

Many years ago, I too had a Volvo that wouldn't start after a fairly heavy rain. Turned out to be the cowl vent drain allowing water to splash over the distributor. I fixed it by extending the hose down along side the bell housing.

 

Is there any way water is leaking under the hood? Try using a hose to look for leaks.

[mfd1rescue]

Truck has spark. If you pour a little gas into the throttle body it will run till that fuel is gone. Havn't checked fuel pressure yet, I just got in on this and it hasn't rained yet. Maybe I will wet it down with a hose and then check it. I was hoping maybe this was a common problem and someone would say dah, it's this or that. thanks for the help. Keep em coming

[polxc7]

Truck has spark. If you pour a little gas into the throttle body it will run till that fuel is gone. Havn't checked fuel pressure yet, I just got in on this and it hasn't rained yet. Maybe I will wet it down with a hose and then check it. I was hoping maybe this was a common problem and someone would say dah, it's this or that. thanks for the help. Keep em coming

[polxc7]

Truck has spark. If you pour a little gas into the throttle body it will run till that fuel is gone. Havn't checked fuel pressure yet, I just got in on this and it hasn't rained yet. Maybe I will wet it down with a hose and then check it. I was hoping maybe this was a common problem and someone would say dah, it's this or that. thanks for the help. Keep em coming

 

 

 

Try the coil wire if not the wire connection on top of the tank. May be a bad ground?