[1/4-horse]

I've got a box stock 600 vacuum secondary on my car. 302/Performer cam/Weiand stealth intake.

At idle, and when you first get on it, it smokes black. I've adjusted the air bleeds, but it still smokes. What else can do this?

Can a new power valve be blown? That's what the consensus around work is, but it's never been backfired.

I'm confused...

Jay

[JBIGBOOTSY]

My buddy has a 600 dbl. pumper and an e cam and It seems no matter what we do It allways Idles rich.

[1/4-horse]

Have you changed jets? My buddy suggested going a size smaller a little while ago. I wonder if that'll help? Are they marked what size they are, so I know which way to go?

Thanks,

Jay

[JBIGBOOTSY]

yea they're stamped. we jetted it down but, the plugs read lean so we put it back. My buddy has just been dealing with it. most likley the power valve is not blown out, I've never heard of one going with out a really good backfire. have you fully cleaned all the circuts in the carb, if not that might help.

[stang fanatic]

refresh the nogggin...isnt the stealth a single plane manifold? dual and single plane manifolds create different vacuum signals thus create different idle and performance characteristics of the carb. whats impoortant is overall running/plug performance and off idle response.

[1/4-horse]

The intake is a dual plane, so maybe it isn't a Stealth... I got it on the engine, which I got from a neighbor. Anyhow, even after resetting the air bleeds, it's still smoking. Mind you, it's not a 4th of July barbeque smoke, just a wisp, especially noticable at night (in other peoples headlights).

Thanks for the leads thus far...

Jay

[Mr_Evil]

You may have large squirter making it a touch rich when you romp' on the pedal. If it runs well, I wouldnt worry about it.




As for idling rich. No matter how your Holley is set up, the idle screws should adjust it if they work properly. One problem may be that you have the throttle screw adjusted to where your throttle is too open.

[1/4-horse]

There's only one reason why I am worried about it, it's staining my bumper! :wink Damn white cars!

I guess I'll just have to clean it more often.


Thanks,

jay

[stang fanatic]

Im still at work....gotta go through the holley book....theres something to be done to correct a rich bleed circuit

[stang fanatic]

ok....im not gonna tell you all about drillling air bleeds and all cuz its clear you dont have a back-up carb if you over do it. Anyways, be sure your choke isnt hanging up, and when hot.....re-tune the mixture screws with a vacuum gauge. your looking for the highest vacuum possible. your cam isnt that big, so idle vacuum shouldnt be that big of an issue from the cam.

[1slo5.0]

A Weiand Stealth is a dual plane intake. Main jets on a Holley have nothing to do with the idle mixture. Somethings to look: transition slots - small slits on the bottom side of the carb in the throttle bores. The throttle blades should be open only far enough to keep enough of the transition slots covered so they make a square instead of a long slot and not open much more than that. Some times it is necessary to drill a small hole in the primary throttle plates to allow more air at idle and when the idle circuit is in use. If the idle mixture screws don't make a difference then you probably need to drill the throttle plates. A bad power valve or wrong size power valve will cause these issues too. What size power valve is in the carb now? What is the manifold vacuum at idle? Retarded ignition timing could be a factor as well.

[1/4-horse]

It turned out the idle speed screw was adjusted to far out. I backed it off, and after some trial and error, it's much better now.

Thanks everyone for the replies!

jay