Bang and smoke.. Please help me

[Scrawford1958]

I have a 1996 chevy Silverado with 200400 miles. When I tried to start it this morning I heard a loud bang and lots of white smoke came from under the hood. Now when I start it, it's very loud "from under the hood" and the engine runs away...like I have my foot on the gas pedal.
Can someone please help me?

[j cAT]

Originally Posted by Scrawford1958

I have a 1996 chevy Silverado with 200400 miles. When I tried to start it this morning I heard a loud bang and lots of white smoke came from under the hood. Now when I start it, it's very loud "from under the hood" and the engine runs away...like I have my foot on the gas pedal.
Can someone please help me?

check that the throttle plates are closed fully ,,coud be a rat got in there and caused the throttle to stick open

[Ol'Jim]

I am curious to find out what happened on your truck.
Did you open the hood, and pull the air cleaner off to have a look?
Are the throttle plates closed, like j-cAT mentioned?

[Scrawford1958]

Jim, my intake manifold blew up. Not the lower part but the plastic part between the throttle body and the lower intake. My problem now is, I have no idea what caused it. I've been told it could be a stopped up catalytic converter or the fuel pressure sensor is dab. Any way, I'm going to replace the intake and fuel pressure sensor today.

[j cAT]

[quote=Scrawford1958;7205740]Jim, my intake manifold blew up. Not the lower part but the plastic part between the throttle body and the lower intake. My problem now is, I have no idea what caused it. I've been told it could be a stopped up catalytic converter or the fuel pressure sensor is dab. Any way, I'm going to replace the intake and fuel pressure sensor today.[quote]

fuel problem, leaking down in intake

[Ol'Jim]

Interesting. Haven't heard of that happening before, but I have often wondered how durable the plastic intake manifolds might be over the long term.
Please let us know if that gets it back up and running. Or if you need additional help.
Sounds like a bad F.P. Sensor could cause that problem.

[Scrawford1958]

Hey Jim. I changed the intake manifold yesterday. I found out it was the fuel pressure regulator. Apparently there is a thin diaphragm in there a new it ruptured letting gas drop into the cylinders all night. When I turned the key it ignited and blew up. I'm surprised my truck didn't catch fire and burn.

[Tech II]

I have heard of that happening on a 3.8, because the f/p reg leaked......

4.3, 5.0, or 5.7?

[j cAT]

good you troubleshooted the failure properly before you installed another intake..

the GM plastic intakes did have problems with the 1st gen DEXCOOL formula . this caused the plastic on the engines and gaskets to break down [was a lawsuit] ..

I believe now we have the 3rd gen DEXCOOL formula which does not damage plastics/gaskets .. this failure on these plastic intakes was back in the 1990's .. GM never tested the 1ST GEN Dexcool compatibility to engine parts.

[Scrawford1958]

5.7

[Ol'Jim]

Yep. Good job, thanks for sharing.