'99 Chevy 2Dr 4wd

The check engine light is on. A new fuel pump and fuel filter was put in recently. One mechanic said it might be the timing chain, and another said the water pump.

Have it scanned for codes then and post back here. That would point us in the right direction.

ok

My father gave me a complete list of new parts on the truck: New rotor cap and button along with new wires and plugs New fuel pump and filter New fuel sensor module on the fuse panel

See, there is whats called an OBDII computer in there that will set a code or codes when something is wrong with the engine. Thus it will turn on the check engine light to make you aware something is going on. Just guessing here I would look at the throttle body's base gasket. they will deteriorate threw time and develop a vacuum leak. Or you could have an injector problem so since you have a new fuel pump in there I would do a fuel bleed down test by hooking up a fuel pressure gauge, and turn the key to on, let it build up pressure, turn the key off and watch the gauge. It should not drop down more than 5 lbs in three min. If it does the there is a problem with the spider injection assembly. If you want to just check those things it wouldn't hurt.

Thanks, I'll post the results if everything goes well

Just post the results, we always like to know what you find.

I kinda wanted to know the codes too