318 Poly idling question

70DartMike said
Alright, here's an update to what's been done.

- I did a valve adjustment, and it now runs a lot smoother (when it runs..)

- It has a new fuel pump

- New fuel filter

- I changed the gas tank last night, the old one was full of buckshot and rocks.. I put in a tank that was totally clean

- I changed the coil to a known good one

It still is doing the same thing. Idle for roughly 2 - 3 minutes, then die. It will start up again, but die quickly. No sputtering while dying, it just quits on me. Could some crap have gotten past the filter and into my line between the fuel pickup and the fuel pump? The filter looked to be good, not punctured or rotten or anything. The filter is dry once the truck dies, and only gets a little bit of fuel in it when I pump the pedal before starting it.

Was I the only one that caught "filter is dry once the truck dies" here?

First of all I suggest you test it above idle. Start it and run it up above 1500 rpm and hold it and see if it dies. If so you know it's not dying at idle because of some problem in the idle circuit.

If it dies that way, then I would eliminate or confirm a fuel supply problem by running the engine from a separate gas can hooked to the fuel pump.
If it doesn't die then you've found the problem, if it does then you know it's more likely there's a spark problem.

I don't think 5 minutes is long enough to bring out a heat related spark issue, but to be sure I would obtain one of those inline spark testers that flashes with the engine running, and also i would check to make sure the coil isn't losing it's voltage supply somehow.

You'll get to the bottom of it. Just follow the trail and see what it "runs out of" when it dies.