EMPI carbs - idles then dies?

[bobswei]

I have new EMPI carbs on our '74 2.0L and it runs very good but sitting at a red light, it idles around 1500 for a few minutes then instantly dies. Many of the electrical stuff is new or replaced. When cold, it idles close to 1k and within 10 minutes the idle slowly goes up to 1500, which I'm OK with since it runs well. But, letting it idle for a few minutes, it dies like you turned the ignition off. No slowing of the idle, no stumbling, just dead. Then starting it, it will crank, stumble and not start. Let it sit for a few minutes, and it starts. Today, I parked it at home, engine warm, and let it idle. Maybe 5 to 7 minutes before it died.
Any idea what's going on?
Thanks in advance.

[Dave at Pelican Parts]

Three things needed to run: Fuel, air, and spark.

Of the three, air is the least likely to suddenly go missing.

Electrical problems can cause the spark to stop. If you get it into a failed state, you can use an extra spark plug and wire to check for spark when the starter cranks.

Fuel problems can have many causes. Is there fuel in the carb float bowls when the engine dies? Does the fuel pump run with the engine running? (How is the pump powered?)

Check the basics and see what element is missing to make the engine stop running.

--DD

[bobswei]

Good suggestions Dave. I have thought the faster idle was because it was a little lean. So maybe a dirty fuel filter but the fuel pump is "on" as long as the ignition is on. I never thought of a spare plug and wire to test. That would make it easier. 45 years playing with Porsches, I should have a spare or 6. And yes, maybe the float bowl is dropping to low if there's a dirty filter. I'll check those things when I get back to "914 day".
Thanks Dave

[John Rogers]

Do you have a fuel pressure gauge in the feed line before it goes to both carbs? Generally 3.5 PSI is okay for carbs, any higher pressure can cause flooding or the same as raising float level.

You mentioned new carbs, did you open them up, check for sticking or too high float levels or make sure all internal passages in the carbs are clean. Finally is the manifold to head gaskets sealing ok or the carbs to manifolds gaskets sealing ok by spraying some carb cleaner at all joints.
John Rogers the oldracer

[bobswei]

No, I don't have a pressure gauge on the car but I do have one I can hook up. I did a quick eyeball check on a few things. All the nuts are tight on the carbs and manifold, but I don't have carb cleaner to spray at this time. Then I stuck the fuel lines in a container to see the fuel flow. It flows well, not high pressure but constant. The photo shows about 10 to 12 seconds of fuel pump on, combined for both sides. I do see a little rust in the fuel and not sure how it got past the filter. But maybe blocking the idle jets? I've worked on Webers before but never EMPIs. I will remove and clean the idle jets. I hate to take the tops of the carbs off since they're new and seem like sealed nicely. So, I'll try the easy stuff first.
Thanks for the replies.