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Virtual Wrench
Virtual Wrench, Master Mechanic
Category: Car
Satisfied Customers: 14620
Experience:  35 years/Master Tech. Foreign and Domestic
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avenger: i crank the motor it kicks..miss..doesnt sputter oranything

Resolved Question:

i have a 560 truck avenger holley carb i put on a 350 all my floats are set right but when i crank the motor it kicks off great and i can give it gas and it doesnt miss a beat but when it drops to 2000 rpms it just dies doesnt sputter oranything it dies just like if you where to turn the key off what can i hav wrong on it
Submitted: 5 years ago.
Category: Car
Expert:  Virtual Wrench replied 5 years ago.

So it wont idle below 2000 rpm without stalling?
Customer: replied 5 years ago.
right it just cuts off almost like its not getting fuel but their is plenty of fuel in the carb
Expert:  Virtual Wrench replied 5 years ago.
Thanks ,

I am willing to bet money on a vacuum leak somewhere.

Give me a minute to type out what you need to do and i will be right back..
Customer: replied 5 years ago.

alright thanks

Expert:  Virtual Wrench replied 5 years ago.
Sorry for the delay bud, i was helping a guy who is broken on the side of the road..

Do you have a can of carb cleaner spray?

Do you have a vacuum gauge?

Are you and the vehicle in a position right now to ck a couple of things for me?
Expert:  Virtual Wrench replied 5 years ago.
Are you running a stick or auto tranny?
Customer: replied 5 years ago.
im not at the truck i dont have a vaccum gauge i did crank it and sprayed carb cleaner in it a few times then the truck started ideling good around 500 rpms i killed it and cranked it two more times and it ran like a charm but i let it sit for about and hour or 2 and cranked it again and it just went back to the same stuff cutting off when it gt around 1500 2000
Expert:  Virtual Wrench replied 5 years ago.
Got ya,

It sounds like the fuel psi is dropping off.

Does it have a mechanical pump or electric?

Also what kind of vehicle is this Avenger Carb on? (Sweet carb by the way)
Customer: replied 5 years ago.
it has a mechanical pump i put a filter between the pump and the carb im sorry i ment 670 truck avenger holley, but its on 350 motor i pulled out of a 68 chevey put it on a toyota for a mud truck with auto trans with slap shift but thats what it seems like to me its loosing psi on the fuel but i just put that pump on today and the carb is getting fuel it doesnt look like its dripping out of primary when trying to idel
Expert:  Virtual Wrench replied 5 years ago.
Thanks man,

Auto tranny or manual shift?
Customer: replied 5 years ago.
Expert:  Virtual Wrench replied 5 years ago.
Yea i just seen that you already told me, sorry,

It s sounding more like a stall issue with the torque converter bud.

Do you have any way to do a stall test?
Customer: replied 5 years ago.
ive never done one how can i do a tall test, i havent put it in gear im just trying to git it to sit and idle right i had the old 4 barrel carb i guess u call it that was on it and it ran fine all day long just when i put this holley on i went to shit but does the converter play a role in it when its in park and your just trying toget it to idle right
Expert:  Virtual Wrench replied 5 years ago.
Thanks for those details bud, it really helps me pull this all together.

So with the old 4bbl carb it run ok and it was after you stuck the avenger on it is when it turned to shit?
Customer: replied 5 years ago.
yeah it was running perfect i drove the truck around and everything i orderd this avenger carb and i put it on pump the pedel once to get a little fuel in it and crank it up doesnt miss a lick cranking and if i give it gas runs great but when i get off the gas and it idles down to 1500 2000 it shuts off
Expert:  Virtual Wrench replied 5 years ago.

I'm wondering about the base plate gasket thats between the carb and intake....sounds like its sucking air....

Did they give ya a couple different base plate gaskets when you bought the carb?
Customer: replied 5 years ago.

i had to go buy an adapter plate and they gave me two gaskets i havent checked on the bolts sence i put the plate and carb on i cant really hear if its pulling any air due to the headers being right their

Expert:  Virtual Wrench replied 5 years ago.
Yup, real hard to hear a vacuum leak.

Anyway, these are real sweet carbs but there is an area that will suck air like a biker chick suck starting a harley...cant hear it but you know its

Here are a couple of diagrams of the base of that carb. The one with the red circle is what i just circled to show you where these gaskets always leak and the other one is without the red circle.


I dont think you need to do it right now, but you should adjust the float levels.

Click here for all the adjustments and specs for this carb.

Its been good working with you and if you have any further questions just give me a holler!

Customer: replied 5 years ago.
thanks man ur giving me somewhere to start over at
Expert:  Virtual Wrench replied 5 years ago.
My Pleasure bud.

Just keep in mind that you can still come back here to this question ANYTIME, in other words after we finish tonight and you accept my help, you can still come back right to this question and we can kick around any other concerns you might have.

Thanks for using Justanswer bud....i have been wenching for over 35 years and i really enjoy helping other people out.....and its cheap huh?

Thanks man, see ya later

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