holley tuning?

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holley tuning?

Postby DjTy » Thu Jan 25, 2007 8:13 pm

Can anyone with some experience in tuning a (vacuum secondary electric choke) 4barrel holley give me the low down on getting it set up ideally without any guages, but just by ear?

I think I might be running a bit rich, when revving it will puff out a tiny bit of smoke not sure what color as it is just a bit and comes out when I let off the rev .

sometimes it seems the carb keeps dropping a bit of gas in the manifold which gives the smell of gas. I saw it spraying it once with the car turned off, I think it might be the accellerator pump, but, I'm not sure.

I have just adjusted the valves, and I was adviced to recheck the timing, and calibrate the mixture screws of the carb. also I have not adjusted the holley regulator at all, from it's factory stock setting, it's just between the 14psi pump and the 670cfm street avenger.

usage is weekend driver and second car. (when first is to work with the girl)
-Chevy Monza '76 2+2 V8 262ci (old) -> 355ci (oil problem) -> 355ci (piston broke) -> 350ci (current) ... LOL
-Opel Kadett E 1985 1.2Litre (Back up, had a broken condensor :P still need to find replacement accelerator pump membrane...)

My Monza in Cardomain!
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1976 Chevrolet Monza 2+2


Postby shytebucket » Sun Jan 28, 2007 1:38 am

Best thing for you to do is perform the basic adjustments outlined in the manual and leave it at that. If you lost your instruction sheet you can download it from Summit below.

Idle fuel pressure at the carburetor inlet should be 5-6 psi max. You should check that with a gage. The puff of smoke is probably just the high vacuum pressure drawing a bit of oil past the rings when the throttle snaps shut and the rpm is high. Nothing to worry about; mine does that too when its wide open and I shift.

http://store.summitracing.com/partdetai ... toview=sku
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Postby DjTy » Sun Jan 28, 2007 9:42 am

tnx for the comment bucketman, but fuel guages are not easy to find, and the oil guage my dad had to buy (on his work's tab).

It may indeed be that it's set too high which causes the smell of gas after shutting down?

Anyway, so basically the manual suggests using a fuel guage, vacuum guage, tachometer (mine's not working correctly at all as I've posted about before) I don't have none of these, so that's why I asked for the "gut" feeling you guys tune a carb with ;)

I think I only have to get the mixture screws correctly...
-Chevy Monza '76 2+2 V8 262ci (old) -> 355ci (oil problem) -> 355ci (piston broke) -> 350ci (current) ... LOL
-Opel Kadett E 1985 1.2Litre (Back up, had a broken condensor :P still need to find replacement accelerator pump membrane...)

My Monza in Cardomain!
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DjTy
 
Posts: 553
Joined: Mon Jun 26, 2006 10:08 pm
Location: Netherlands Antilles

1976 Chevrolet Monza 2+2

Postby shytebucket » Mon Jan 29, 2007 3:58 am

Ok, if you know a mechanic who has these tools you could borrow or get him/her to help you that would be best.

Regulator - should have been preset by Holley to give an acceptable pressure (check your instruction sheet). You only need to double-check it with a gage.

Idle speed - set the screw to give the lowest engine speed without any sputtering or stalling (in drive and engine warmed up).

Idle mixture - start with 1.5 turns out (see instructions) and adjust them rich or lean only if the engine is stumbling/misfiring at idle or very light throttle. But don't be afraid to experiment a little.

Leave your secondaries alone until you have everything else worked out.
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