edlebrock 1406

[greasemonkey71]

ok i have an eb1406 with the stock jetting its on a 350

replaced basically my entire ignition system new points ,distributor, rotor, plugs, and coil.

my truck was sputtering when i gave it more than half throttle while i was in drive so i rebuilt the carb with the stock jets

i live in san diego basically sea level

my motor still sputters like its not getting gas whn i give it more than half throttle..im starting to getr frustrated andf pissed cuz im stumped

any help with this would be greatly6 appreciatd

[72chevyk10]

mine used to do that. turns out i had a vacuum leak on the back of the carb, giving a weak signal to the secondarys. my intake is a spread/square bore. and needed the adapter to make it work correctly. put it on and now it works perfectly

[greasemonkey71]

ill check mmy vacuum lines today

do u have any sputtering?

i have the edlebrock performer intake

[etg]

This seems to be a common problem with the 1406. Here is a link to the owner's manual, read it and become familiar with tuning your carb because even elevation changes can alter performance:

http://www.edelbrock.com/automotive_new/misc/tech_center/install/1000/1406_manual.pdf


The problem could be that your secondary jets are not pumping either enough fuel or quickly enough. Before half throttle you only use primary jets, after the halfway mark it opens up to feed the intake from the secondarys as well. If there is not any fuel there it causes a lean condition that can produce sputtering and even backfire through the carb. Read up on how to adjust this, and you will be happy you learned about the carb.

[chopnchaneled]

For sure i'm a newbie, but i was just reading about the sock in the gas tank getting clogged and causing what your describing?

[etg]

That could be the problem, if there's not enough fuel getting in it can also create vapor lock. Is the problem worse worse when you gradually accelerate to full throttle? or is it only when you stomp on it?

[greasemonkey71]

i can ease into it until about half throttle then it all goes to **** from there

[heeroyue2002]

i have the same carb, where did you get your rebuild kit.

[greasemonkey71]

i bought little edelbrock kit from pep boys

[s102000]

Could be as simple as a clogged fuel filter, just a thought...

[VDOG]

Had the same problem, edelbrock said it was my cam. Yeah right, turned out to be a vacuum leak, my head bolts by my plugs were finger loose.
Check everything that deals with vacuum.

[BB72CHEVKT]

Originally Posted by s102000

Could be as simple as a clogged fuel filter, just a thought...

this would be the first thing I check and it is cheap too

[72chevyk10]

Originally Posted by greasemonkey71

ill check mmy vacuum lines today

do u have any sputtering?

i have the edlebrock performer intake

after i got the vacuum leak fixed it runs like a dream. however i did change the secondary jets 1 "stage" richer for my carb before i found the leak. mine is the 750 performer

[greasemonkey71]

well i went and looked to see if any fuel squirted out the the secondary throttle and nothing happend...

..replaced th fuel filter

..fuel pressure good

ill pull the carb off the truck tomo at work and ill see if th jets are clogged

[72chevyk10]

Originally Posted by greasemonkey71

well i went and looked to see if any fuel squirted out the the secondary throttle and nothing happend...

..replaced th fuel filter

..fuel pressure good

ill pull the carb off the truck tomo at work and ill see if th jets are clogged

by secondary throttle do you mean the accelerator pump? or fuel coming out the back 2 barrels? free reving the engine almost never gets a signal to secondarys, so you wouldnt see anything.. ill bet you have a vac. leak around the back of the carb. spray some wd-40 or startign fluid around the base of the carb all the way around. if the engine changes rpm or sounds diffrent at all you have a leak.

[greasemonkey71]

on the back of the carb theres a brass fitting like the big one on the front of th carb...

when i got the truck the PO had a hose running from the bac of the carb to the valve cover on the right side of the motor

[etg]

There are 3 vacuum ports on the front and one on the back of the carb. The front passenger side goes to the vacuum advance on the distributer. The middle one is a pcv port, this should be the one that runs to the valve cover not the one on the back. The front drivers side should just be capped. The back vacuum port is for the brakes.

[greasemonkey71]

ok...ill switch those around today on my lunch break

[greasemonkey71]

ok i got all the vacuum lines figured out except the back...

i dont know where that would hook up to

[smn69]

The one on the back goes to the brake booster if you have one. If no power brakes, just plug the back port.

[81ShrtBox]

Originally Posted by etg

There are 3 vacuum ports on the front and one on the back of the carb. The front passenger side goes to the vacuum advance on the distributer. The middle one is a pcv port, this should be the one that runs to the valve cover not the one on the back. The front drivers side should just be capped. The back vacuum port is for the brakes.

Originally Posted by 72chevyk10

by secondary throttle do you mean the accelerator pump? or fuel coming out the back 2 barrels? free reving the engine almost never gets a signal to secondarys, so you wouldnt see anything.. ill bet you have a vac. leak around the back of the carb. spray some wd-40 or startign fluid around the base of the carb all the way around. if the engine changes rpm or sounds diffrent at all you have a leak.

I did a rebuild this summer... put a Edlebrock 1406, Will Hoite Roller Cam, GM Z06 Bee-hive Springs, vortec swap in my 81"... It has been giving me the bluez. I'm having the same issue with the engine falling on its face above 3,000 rpm. I will order a rebuild kit and see if i can get this problem solved. I was about to take the engine out and tear it apart

[72chevyk10]

Originally Posted by 81ShrtBox

I did a rebuild this summer... put a Edlebrock 1406, Will Hoite Roller Cam, GM Z06 Bee-hive Springs, vortec swap in my 81"... It has been giving me the bluez. I'm having the same issue with the engine falling on its face above 3,000 rpm. I will order a rebuild kit and see if i can get this problem solved. I was about to take the engine out and tear it apart

depending on the size of the cam, you may be runing lean. the stock setings for a 1406 are for a stock 350. and sometimes even to lean for stock..

[greasemonkey71]

this damn thing has me confused

is there any one in the san diego area who could possibly help me with this thing

[81ShrtBox]

Originally Posted by 72chevyk10

depending on the size of the cam, you may be runing lean. the stock setings for a 1406 are for a stock 350. and sometimes even to lean for stock..

Cam is a
270 Adv Dur
Intake lift .495/.218@50
Exhaust lift .502/.224@50

I'm really thinking about putting a wideband on it to monitor my air/fuel... I'm adding NOS later so I might as well get it now

[81ShrtBox]

Originally Posted by greasemonkey71

this damn thing has me confused

is there any one in the san diego area who could possibly help me with this thing

I know how you feel... I'll try working on mine maybe next weekend.

Try and see if you can find someone to mail the carb to if you have to..