Carb Popping at Idle

[Dirty Marty]

Took my bone stock 911T out for a few weeks of freeway commuting and the old girl ran just fine. I was driving home last night and when I'd come to a stop or light, I'd get that "pssst" out of one of the carbs. When I got the revs up everything was fine but at idle I'm getting the "psst" sound and the idles rough as well. What gives?

Dirty Marty [img]http://forums.pelicanparts.com/support/smileys/roker.gif[/img

[Peter Zimmermann]

Marty: With the car warm & idling unscrew, one at a time, your idle fuel jets (the row of three slot-head screws along the outboard side of each carb almost at the top). Work with clean hands, separate each jet by pulling it apart from its carrier, and hold it up to a light to be sure that the orifice is clear. Sometimes a chunk of crud large enough to plug the hole in the jet's tip is easily seen. Again, do one at a time, start to finish, and be careful to not overtighten them when you put them back in. Good luck!

[2.7RACER]

What Z said.
Although I check my idle jets with the engine off.
Check the O-rings, if in doubt replace the O-rings.
Put a drop of oil on each O-ring before you replace the idle jet holder screw.

[Peter Zimmermann]

Originally Posted by 2.7RACER

Although I check my idle jets with the engine off.

Doug: Believe it or not, I've found over the years that if the jets are removed while the engine is idling there is a better chance that, if debris is in there, it will stick to the jet and come out with it. Sometimes, if the engine is shut down, the crud will fall off the jet and stay inside the carb - of course, this is not always the case, but after fixing a particularly troublesome car I switched my thinking and always do the checking/cleaning while idling.

[2.7RACER]

Hi Pete,
That is great info. I'll try it. Thanks.
Unrelated question.
Do you have any connection to John Zimmerman?

[berettafan]

Pete that's an interesting tidbit there, thaks for sharing!

i guess no fuel spurts out?

[Peter Zimmermann]

Originally Posted by 2.7RACER

Do you have any connection to John Zimmerman?

No, there is no "John" in my family.

beretta: No, fuel will not spurt/run out of the idle fuel jet holes - if it does we've got real problems !!