QIK E

I know this is isn't an ls1 question, but I figured I'd give it a shot here since I don't know of any GMC truck sites.

I bought a 97 GMC 5.7 Sierra. The engine cranked fine when I got it, but the previous owner said if it sits for a while it's hard to crank. Last week it hesitated to start, but eventually did. This week I'm not so lucky.

Here's whats going on:
I hear the fuel pump whine when I turn the key.
The battery has full charge. I put a external charger on it.
I just replaced the spark pugs today and that didn't solve the problem.
When the engine is turned, sometimes it clunks a couple times then stalls and black smoke comes out of the air intake.

Anyone have any ideas? I'm lost

kmracer

iTrader: (1)

so the engine is turning over but slowly? when it IS running, does it run healthy?

QIK E

Yeah it turns over Fine like it's about to start but it never gets going....when it is running, it runs like a top...no squeaks no rattles

Captain_Stabbin

cap/rotor? maybe timing?

fleetmgr

Have you put a gauge on the fuel system to check pressure? Just because you hear the fuel pump run doesn't mean you have any fuel pressure.