why does it turn off?

[yukonaetahoe]

My cousin has a 96 gmc pickup. We have been having this problem were when we come to a stop light it turns off. Itll turn right back on, but its weird that it will only turn off at a stop light or stop sign. only a complete stop.
Now it did it on the freeway! it shut of for like a second and turned back on WTF!
anyone have this problem before? im assuming maybe it has to do with some air intake problem maybe the manifold but ofcourse idk what im talkiong about. please help!

 

[Effeckt]

I'm sure the experts here will know more than I do but I would be inclined to believe it has to do with the electrical system. It almost sounds to me like it is shorting out for a second which would be why it fades out a comes back on. Like I said though, I'm no expert but that is what I would guess.

 

[718frankb]

check and clean battery terminals and make sure your grounds didn't rot off. thats where i would start!

 

[dwmmatt23]

mine has started to do the same thing, believe it has to do with my ground or terminals. just havent had the time to pinpoint it yet, and it did it three times only one day and havnt done it since

 

[yukonaetahoe]

thanks guys!
we were moving the relays under the hood and noticed the fuel pump relay was very loose so we wiggled it and it turned off the truck. he put in a new one which is way more snug fit and it hasnt turned off......but i will def check the wires for rotting because that did happe to my yukon last week aswell. thanks !!!

 

[chris.]

Mine has had similer issues as well, and what it came to be was the actual fuel pump, or to more detailed the plug going into the pump from the truck, if my tahoe wasnt full of gas, what i think was happening was the gas would move to the front of the tank and either starve the pump located at the rear of the tank or shift the tank just enough to wiggle the plug breaking connection thus shutting the truck off but mine as well would start back up...long story short check the mentioned above. Good Luck, keep us posted!

 

[ravingmadman]

If it isn't throwing any codes, I'd go for the grounds, and the fuel pump. I'm not sure why, for all the sensors and extra crap they decided to monitor, GM couldn't include a fuel pressure sensor to tell us when the fuel pump is dead or dying. But if you haven't done the big 3 yet, start with that.

 

[yukonaetahoe]

If it isn't throwing any codes, I'd go for the grounds, and the fuel pump. I'm not sure why, for all the sensors and extra crap they decided to monitor, GM couldn't include a fuel pressure sensor to tell us when the fuel pump is dead or dying. But if you haven't done the big 3 yet, start with that.

ive hurd the "big 3" before. what is that?

 

[haks310]

Better grounds.

Battery to Alternator
Engine to Frame
Battery to Engine

And there is one connection going from the battery to the fuse panel you can also do.