i need some help.. my 4150 wont work.. we took it apart cleaned it.. blew everything out wiht carb cleaner.. and it didnt help.. it wont let my engine start.. its like the only thing working is the accelerator pump.. casue i can get a pop pop pop if i use the throttle to squirt some fuel in from the accel. pump... i've adjusted all 4 of the corner idle screws 1.5 turns out... and i adjusted the idle screw for the throttle also...

stock it had 10.5 and 8.5 powervalve i think now they both are 6.5.. would that make a diffrence?
what should i check?
please help...

[This message has been edited by 1981coupe400ci (edited April 04, 2005).]

both bowls are full of fuel?

try filling the front bowl through the vent tube then pour a little down the carb it should fire up and run

its getting fuel into the bowl.. cause i have about 6.5PSI at the carb, and i've taken both fuel bowl site screw out and they fuels right there... i can rock the trottle back and forth and it sprays in fuel becasue of the accelerator pump.. but after the few pops i get nothing...

i'm ready to just cut this as a $115 loss and go buy a new one...

a 3310 holley 750 vac secondary carb never came with 4 corner idle mixture screws!!.also this carb never had a rear power valve.now are your float levels correct ?? checked by turning the float bowl upside down and making sure the float is level with the bowl.

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1972 chevy camaro ss 350 sbc 425 hp/356 @ the wheels,350 trans,373 gears,daily driver with restification in progress for the old school / day 2 look
future plans- turning it into a baldwin motion Z30 clone

"IF IT'S TO LOUD YOUR TO OLD"
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Power valve changes won't affect the idle circuits at all. The idle circuits draw the tiny amount of fuel they consume from the main fuel wells which are fed by the main jets and power valve (neither of which is a restriction to fuel flow into the idle circuits since they draw such a tiny amount of fuel).

Besides, when you are cranking the engine over on the starter the power valve is always open regardless of it's rated opening point since there is no meaningful amount of manifold vacuum anyway.

Agreed, a 3310 vacuum secondary carb is not a 4150 carb anyway. It's a 4160 style carb with a secondary metering plate, vacuum-operated secondaries and no secondary side accelerator pump.



[This message has been edited by Damon (edited April 04, 2005).]

<font face="Arial,Verdana" size="2">Originally posted by muscl car:
a 3310 holley 750 vac secondary carb never came with 4 corner idle mixture screws!!.also this carb never had a rear power valve.
</font>

I used to have a 780 vc with 4 corner idle and front and rear power valves!

You sure you have the correct gaskets?
You sure its getting fire?
If you dump some gas directly in the carb it should start if only for a few seconds if its fuel
You sure it hasn't flooded and washed the plugs? Doesn't take much and if you've given
too many pumps with the accel. trying to start it you could have washed them out!

the carb is a 3310-1 (3310-1 780cfm jets(F)72,(R)76 powervalves 10.5,8.5 series 4150


its definitly getting spark ect... if i rock the throttle back and forth and then let it sit for a sec.. then turn it over i'll get a pop pop pop... and then it dies... if i do it while working the throttle same thing.. pop pop pop. then nothing.. so the only fuel its getting i think is from the top of the carb from the accelerator pump holes i can see the fuel shooting into the carb from the top holes(primary only since its vac sec) when i rock the throttle..

would blown power valves make it so it would be like that?? i did get a few good carb backfires before i got the timing all figured out...

i was told a rebuilt kit might not help... so i dont wanna waste more money if it wont...


does anyone here completly rebuild carbs from recoating to calibrating??

Do you have one of those round spectre/mr gasket fuel pressure regulators on it? If so, remove and retry.

MaTt

nope no regulator.. stock pump(used about 5min on one of my other engines i sold) with PSI gauge on the dual feed line thingy... says about 6.5PSI or so...

i'm gonna tear it down COMPLETLY and soak all the parts in carb cleaner, and blow out every piece.. and do a full rebuild on it.... if it still dont work.. expect a parts carb to up forsale in the swap meet section...

[This message has been edited by 1981coupe400ci (edited April 05, 2005).]

Yea - before you tear it down, I think it's permanently damaged - brain dead Holley so don't waste you time working on it. Sell the worthless thing to me for $10... LOL When you do your rebuild, I think you're likely to find a gasket misaligned or trash in one of the passages. Good luck

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79 Z28 Bought new, honeymoon ride, same wife, same car.

It would probrably backfire out the carb if it was lean and had fire, i bet its not firing

i went out and readjusted EVERYTHING rocked the throttle about 5 times.. let it sit for a min.. turned the key and vroom vroom.. started up and i adjusted the idle speed screw and just let it sit at 2000 for about 15min http://www.nastyz28.com/ubb/smile.gif ... now i can get fuel line and exhaust http://www.nastyz28.com/ubb/smile.gif

the only thing that sucks is the cam doesnt have as much "chop" as i would have liked it to have, it still sounds pretty good though... maybe later when i upgrade the heads i'll upgrade the cam again too...

[This message has been edited by 1981coupe400ci (edited April 05, 2005).]