Quadrajunk

[bitchin85]

well the 1406 edelbrock 600 on my truck is pretty much garbage. it barely idled, bogged like no other, and had real bad pickup. im tight on cash so i figured id try out the stock quadrajunk on my edelbrock intake.the rest of the motors pretty much stock except exhaust. it started kinda rough but seemed to run better all in all. it doesnt bog anymore when i craack the throttle but it idles very high. i had the screw backed all the way out, and it still idled high. i sprayed all over for vaccuum leaks but didnt find any. maybe i have a vacuum line on wrong somewhere? im not to firmiliar with these things but any tipe on how to tune them? and i think my timings off a little. any tips? thanks

[Scootin 81 C20]

Make sure the throttle isn't sticking anywhere and make sure the choke is working properly.

[bitchin85]

its not sticking

[Restrorob]

Make sure the high idle cam is not stuck, I don't know if this applies to your engine (no info) but if the vacuum advance is hooked to the wrong port it could idle higher than normal.

[Oilbrnr]

Verify the timing and go from there.

[bitchin85]

how do i know exactaly how to set the timing? i always just played with the distributor until it sounded good.. and the vac advance is hooked on in the bottom left side port in the front (looking at the motor from the front of the truck) i have my brake boost on the back, and the pcv in the front bottom middle. everything else is capped

[Oilbrnr]

Seriously? You need a timing light.

[supamatic]

i dont know if u have egr valve but when they cant hold vaccum and dont open the engine revs high and that throws off timming if thats broken thats a therory of mine i might be wrong

[bitchin85]

Originally Posted by Oilbrnr

Seriously? You need a timing light.

100% serious. i wouldnt be asking on here if i knew. and theres no egr on the motor

[CSGAS]

My usual first step before bolting any carb on is rebuilding it using settings appropriate for the application.

There are slots in the primary barrels of the Q-Jet, by the throttle blades, that should only be partly covered at idle...but the first step in making sure this is happening is setting everything one the carb right. If it is right and the throttle linkage rod is adjusted a little short, like for a different carb, then the throttle blades are never reaching idle position.

You'll never know which is which unless you have a known quantity, like knowing the carb is set right. If your Edelbrock manifold is just a Performer (low-rise dual plane) then restoring the stock settings should be a great starting point.

It's not an electric feedback Q-Jet, is it?

[Restrorob]

Sounds like the advance is on the right port, Could be the welch plugs on the bottom of the float bowl seeping fuel/a worn throttle shaft or a higher than spec float/fuel level.

Did you install a new base gasket when you swapped carbs ?

[bitchin85]

It's not an electric feedback Q-Jet, is it?[/QUOTE]

not sure. idont think so. theres no wires goin to it.. its not a performer but it is a low rise and yea i used a new gasket. it doesnt leak any at the manifold

[68 TT]

Cover the front side of the carburetor with your hand. If you can not feel much if any air pulling past your fingers then you probably need a different base gasket.

I just went through this on Sunday. I was having problems with the Edelbrock 1406 on my engine and decided to put the bigger 750 Demon carb off my Camaro onto it. I couldn't get it to idle below 2000 rpm. Switched base gaskets and all is well.

[bitchin85]

so my choke wasnt opening all the way. i overlooked a stupid fuse. now it opens all the way and i put a higher flow air cleaner on it. now it seems harder to start...its my DD so i need to figure something out here fast cuz now its got a choppy idle and it sounds like its going to die. any suggestions? could something be wrong in my distributor to make it miss like it is?

[big10ratrod77]

and another thing is your carb adjusted right? look on my stock q jet the best setting is turn you idle mixture screws all the way in and then 2 and 1/2 turns out on both sides and adjust according so if its lean at top end give it another 1/4 to 1/2 turn on both

[bitchin85]

is the a/f ratio the only adjustment u can do to these things?

[bitchin85]

Originally Posted by 68 TT

Cover the front side of the carburetor with your hand. If you can not feel much if any air pulling past your fingers then you probably need a different base gasket.

I just went through this on Sunday. I was having problems with the Edelbrock 1406 on my engine and decided to put the bigger 750 Demon carb off my Camaro onto it. I couldn't get it to idle below 2000 rpm. Switched base gaskets and all is well.

did you have a thick, stock style gasket or just a thin paper one?

[big10ratrod77]

is the a/f ratio the only adjustment u can do to these things?

its the easyist thing for beginers like me to do and not mess somthing up, which is normal for me but... eny way

[68 TT]

Originally Posted by *****in85

did you have a thick, stock style gasket or just a thin paper one?

I had the 1/4" thick one on there with the 1406 but I also had the rest of the heat shield assembly on there too. I couldn't get the Demon fuel line past the large plate so I left it out on the first try. Apparently the heat shield plate was sealing a gap that the smaller plates are not because it wouldn't idle below 2000 rpm without it and runs perfect with it now that I cut the heat shield to clear the fuel line. I even tried just the 1/4" thick base gasket and it didn't work either.

I forgot to take pics of the trimmed heat shield but I will get some this weekend. I still need to adjust the air/fuel mixture and set the idle.

[Damien]

you change the air cleaner so now you have more air available to the carb and may need to adjust the carb for that.

[68 TT]

^^ I agree. Something as simple as that can cause a lean condition that creates all kinds of tuning and drivability issues.

The stock snorkel air cleaner is very restrictive so the open element air cleaner allows a huge increase in air available to the engine. My old one was necked down so far it only had only about a 1-1/2" diameter opening that all the air had to pass through.

[bitchin85]

thanksguys. today i got so fed up with the carb after me and a few freinds played with it that i swapped it for a 1403 edelbroct 500cfm. i thought it woulld be too small but it runs great now. and i got the timing set. now it runs awesome but it never just stops there, now when the trucks hot, it wont turn over... its been doing this for a while but it would at least start after a few seconds, now it turns over so slow it wont fire. but when its cold its fine. is it my battery? starter? alternator? my first thought was my starter but i could be wrong.. and suggestions?

[79gmcc15]

starters are notorious for heat. because the exhaust is right there. get a starter heat shield and it should be good.

[bitchin85]

Originally Posted by 79gmcc15

starters are notorious for heat. because the exhaust is right there. get a starter heat shield and it should be good.

so keep the starter i got? or just get a new one and a sheild?

[presleyhome]

Timing. Really, get that timing set solid and it will crank fine.

Jim P