1989 GMC XC K1500 Problems

[reynolds]

Hello,

I'm new here, so this is my first post. I have a 1989 GMC Sierra K1500 XC with a 350 V8 5.7 liter engine. I recently bought the truck, and have since replaced the fuel filter, plugs, and distributor cap. I've also had the compression checked, and everything checked out ok. Now, when I try to start the truck, it may "start" for a second then quit. Other times it will start, but then begin to run very rough with white smoke coming out of the dual exhaust. After I give it some gas, it seems to calm down and run normal. But, since I can't always get the truck running, it tends to be a big problem. This seems to happen normally when it has been damp outside, after a rain or some other type of precipitation. I've tried fuel injector cleaner, and I'm not sure if it has helped or not. Any ideas of what I should do, other than junk it?

Thanks,

Chris

[HD Mech]

Hello,

I'm new here, so this is my first post.  I have a 1989 GMC Sierra K1500 XC with a 350 V8 5.7 liter engine.  I recently bought the truck, and have since replaced the fuel filter, plugs, and distributor cap.  I've also had the compression checked, and everything checked out ok.  Now, when I try to start the truck, it may "start" for a second then quit.  Other times it will start, but then begin to run very rough with white smoke coming out of the dual exhaust.  After I give it some gas, it seems to calm down and run normal.  But, since I can't always get the truck running, it tends to be a big problem.  This seems to happen normally when it has been damp outside, after a rain or some other type of precipitation.  I've tried fuel injector cleaner, and I'm not sure if it has helped or not.  Any ideas of what I should do, other than junk it?

Thanks,

Chris

 

<{POST_SNAPBACK}>

 

 

 

Chris,

 

Check the gasket between the TBI and manifold, it was a high failure item for the 89 chev/ GMC. A potion of the gasket may of been sucked into the manifold, which then allows too much air into the combutions process. Even a pin hole will throw off you air/ fuel mixture.

[reynolds]

Hello,

I'm new here, so this is my first post.  I have a 1989 GMC Sierra K1500 XC with a 350 V8 5.7 liter engine.  I recently bought the truck, and have since replaced the fuel filter, plugs, and distributor cap.  I've also had the compression checked, and everything checked out ok.  Now, when I try to start the truck, it may "start" for a second then quit.  Other times it will start, but then begin to run very rough with white smoke coming out of the dual exhaust.  After I give it some gas, it seems to calm down and run normal.  But, since I can't always get the truck running, it tends to be a big problem.  This seems to happen normally when it has been damp outside, after a rain or some other type of precipitation.  I've tried fuel injector cleaner, and I'm not sure if it has helped or not.  Any ideas of what I should do, other than junk it?

Thanks,

Chris

 

<{POST_SNAPBACK}>

 

 

 

Chris,

 

Check the gasket between the TBI and manifold, it was a high failure item for the 89 chev/ GMC. A potion of the gasket may of been sucked into the manifold, which then allows too much air into the combutions process. Even a pin hole will throw off you air/ fuel mixture.

 

<{POST_SNAPBACK}>

 

 

 

 

Thanks for the reply. I replaced that gasket just about a day ago, and it still didn't seem to fix it. Who knows, I guess I'll be checking on some type of sensor problem, or something.

Thanks Again,

Chris

[ockgator]

Since it usually happens after a rain, is the air filter assembly stock or does it have an aftermarket set-up? Even if stock check for water intrusion after a good rain into the air cleaner housing. Also check fuel pressure, needs to be at least 54 psi for the poppets to work,also needs to hold pressure for about a minute(preferably more)after shut down, if pressure drops open throttle body(ENGINE OFF) and check for raw gas smell. There are plastic lines from the main injectors to the poppets that tend to crack