running rough

[bouncytruck]

This morning on the way into work, my truck started sputtering and popping when I gave it some gas. I had to pull off the freeway in fear that it was going to leave me stranded in the middle of I-405 with my 2 year old in back. I turned off the engine, waited a second and started it up again and there were no problems. The engine was fairly warm when I started as I let the truck warm up in the driveway for about 5 minutes before heading on my way.

I'm thinking possibly the fuel filter, but what else could be a common cause. Any other ideas?

[cdowns]

air filter fuel filter sticking choke

[ChevLoRay]

Your question is a good one, but the possible answers are many.

Fuel filter? Usually, you'd notice a problem with fuel delivery when you are placing an increasing demand on the need for more gasoline, at which time you'd find that it is stumbling and easing up on the gas would have it smooth back out.

Spark? Could be a plug wire is breaking down or it could have gotten too close to the manifold/headers and then it could arc to the engine, effectively killing that cylinder.

Ignition points/condenser? If you're still running these, could be the condenser is going bad, and causing the points to "pop". Usually, this condition can be duplicated by revving the engine slowly, and listening for the popping thru the exhaust system.

HEI? My situation one time found that the wiring to the module in the old GM HEI that I had, would break when I let off of the gas, causing the vacuum advance to move the breaker plate that the module was mounted on. Took some time to find this one, for sure.

Vacuum lines? Usually, a bad vacuum line, or a vacuum leak will be more evident at idle. Usually, vacuum leaks will dissappear when you nail the throttle....since vacuum is lowest at WOT positions.

Float level in the carb could be a possible source...like a bit of trash may have found its' way to the needle/seat and created a condition sorta like flooding. In this situation, the needle wouldn't close off, allowing gas to continue to be pumped into the float bowl.....causing it to flood. IF the condition continues, you know the engine is gonna die and you'll know it is flooded.

Check the obvious stuff, first. Most of the time, it will be an easy thing to find/fix. Plugs, wires, cap, rotor, etc.,.....all can cause the problem, but the fact that it "went away" is what will make it harder to find. Fuel is very likely the factor, but the fact that it cleared itself up is going to make that harder to verify without checking the pressure at the carb inlet, or from the pump, or a pump capacity test. If you're running a Quadrajet, and if it still has that old bronze filter, it could be saturated with particles which make it harder to pass liquids through to the carburetor.

Choke pull-off's are notorious for causing these problems, too.

Good luck.

[bouncytruck]

I think I need to do a tune up anyway. I'll start there. Thanks.