Broken idle-mixture needle-how to remove?

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Broken idle-mixture needle-how to remove?

Postby Yellowbird77 » Sun Feb 10, 2008 6:49 pm

I recently rebuilt my carburetor(a Rochester 2GC) and everything seems to be working, except it runs rough and comes close to stalling while it's idling in drive. I've only noticed this with the engine at operating temp.

My first thought was the idle mixture screws are out of adjustment. But then I remembered when I took the carb part, I noticed one of the 2 idle mixture screws had a blunt end where the other had a fine point. I also remember that one of the 2 throttle bores had a tiny protrusion sticking through the side. I think the end of the needle broke in the throttle casting! Anyone have any tips/tricks suggestions how to remove the needles broken-off end? Any suggestions where to get new needles?

Thanks!
Trevor
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Postby NixVegaGT » Mon Feb 11, 2008 10:38 am

The rochester carbs sometimes have mixture screws that protrude into the barrels. It could be that the one that is sticking out is the one that isn't broken off.
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Postby heinz057 » Mon Feb 11, 2008 11:03 am

pictures please
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Postby Yellowbird77 » Mon Feb 11, 2008 6:21 pm

Well, I didn't take any pics of the throttle bore area while I had it apart, but I did take a pic of the needles.

http://www.flickr.com/photos/16700745@N06/2259103542/

My guess is that I'll just have to push the broken tip back thru the hole and try to locate a new needle. I'm pretty sure it was like this before I started working on the carb. Can the other needle be backed out a little more to compensate for the clogged air bleed in the meantime?

It did run properly about 6 months ago, though the idle was a bit problematic then(not nearly as bad as it is now). Now it just comes close to stalling while idling in drive when the engines at operating temp.

My local parts place said they can't order new needles either, anyone know where I might find them? I'm guessing the junkyard might be my best bet if I can't find one here...

Thanks,
Trevor
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Postby spyder_xlch » Mon Feb 11, 2008 7:18 pm

Looks like someone screwed it in alittle too tight. You should be able to push it out carefully. I would think NAPA could get it but a junk yard would be a good place. Take the good one with you and match it up. Best thing is, pocket parts are free.
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Postby Yellowbird77 » Mon Feb 11, 2008 7:28 pm

I'll give NAPA a try, it's worth a shot. Didn't know that pocket parts are free...good to know! Looks like I may be heading down to junkyard this weekend...


Thanks,
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Postby spyder_xlch » Mon Feb 11, 2008 7:32 pm

As long as they don't know they are in your pockets they are free. :lol:
As far as "Can the other needle be backed out a little more to compensate for the clogged air bleed in the meantime?" I don't think that will work if you have a dual plane manifold.
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Postby Yellowbird77 » Mon Feb 11, 2008 7:38 pm

Haha, I thought that may have been what you meant! :wink:

I'll keep on lookin'...oh, any chance anyone would know if the idle mix screws for a quadrajet might fit? I found a site that has them, and they look similar, just not sure if they'd do the trick...

Thanks,
Trevor
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Postby heinz057 » Mon Feb 11, 2008 7:40 pm

they should be the same
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Postby Yellowbird77 » Mon Feb 11, 2008 7:55 pm

Nice! I'll be placing an order shortly...

By the way, Heinz057, where are you in NJ? I'm in Point Pleasant...

Trevor
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Postby heinz057 » Mon Feb 11, 2008 7:58 pm

lanoka harbor. do you have pictures of your car?
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Update on mixture needle prob

Postby Yellowbird77 » Tue Feb 19, 2008 8:33 pm

I located a pair of Quadrajet idle mixture screws from Carbs Unlimited and had the chance to pop em in today(Heinz057 was right, they fit Dualjet carbs too, they're just a little shorter). I removed the carb and managed to get the broken needle point out of the orifice in the throttle bore, put in the new needles and started her up. Everything worked nicely, and it performed better than I think it has since I bought the car over a year ago. I'm still getting a rough idle once the engine's at operating temp(not bad enough to stall out), but I guess it's a matter of backing out the idle mixture needles a bit more? You guys have been very helpful! Thanks!

What a nice feeling it was to finally have her running right after 8 months or so just sitting around waiting for attention... :shock:

Thanks again for everyone's help!
Trevor

PS: I'll get some pics of my car up in the next couple days, she needs a good cleaning... :wink:
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