dead miss new single plane intake carb an ignition

[bigbrute]

I have a 1980 mont 355 convert to 4 speed. I recently put on a new professional products hurricane edelbrok 1407 750 an msd street fire hei dis in. I have a dead miss under a load on num 6 plug I can almost make go away at idle. I pulled the #6 wire an put in a test plug to c if it was getting spark u could weld with the out put . I've re placed wires an plugs. The ignition is completely new. The plugs look. Like they never been used when I went back through an checked them. So I'm guessing its running lean but it smells like its running rich. I'm lost could really use the help

 

[Phoenyx]

I'm gonna take a guess and say that carb is to big. Unless your pushing 500 HP.

 

[CamaroAdam73]

That carb isn't too big.

The 1407 edelbrock's are newer right?? So I'm assuming you have two fuel&air mix screws on the forward face of the carb? Don't get confused, one controls the left side of the carb, the other the right side AND they both control fuel AND air, for the side of the carb that they are positioned on.

Now as far as i know, 5 turns out from all the way in should be factory tuning procedure. So i guess you could start there, if you think the carb is the problem. And all the way in should be SNUG, not TIGHT. you don't want to damage the needle valve. it's a total pain in the *ss to replace, I've learned all of this the hard way.

( i know all of this because i had the exact same carb, 750 performer, and had tons of issues. Turns out it was because somebody sugared my tank)

I would also make sure the timing is set right, you obviously have a timing gun so check it. Make sure you didn't drop the dizzy a tooth off.

If that all fails, check to make sure those intake gaskets are holding up and one isn't leaking/ didn't seal.


I'm also assuming the engine ran fine before the upgrades? if so than that would rule out other problems.

Good luck, hope this helps.

 

[pontiacgp]

I'm gonna take a guess and say that carb is to big. Unless your pushing 500 HP.

x2....a 750 carb is much too big for a 355

here`s the equation to find out what carb is right...(cid * Rpm)/ 2(1728) * Ve= CFM needed..

355x6000 / 3456 x 100% = 616.31

 

[jrm81bu]

That carb isn't too big.

The 1407 edelbrock's are newer right?? So I'm assuming you have two fuel&air mix screws on the forward face of the carb? Don't get confused, one controls the left side of the carb, the other the right side AND they both control fuel AND air, for the side of the carb that they are positioned on.

Keep in mind that those screw are only for IDLE air/fuel mixture.


Intake gasket was mentioned, and possibly a problem with the valves and/or valve seats.

 

[pontiacgp]

I'd try a different distributor.....

 

[bigbrute]

the motor and heads only have anout a 1000 miles on them so the vaves an cam shold be good . ive put the old dizzy back in an it has a better curve on the vac adv but still missing. ive checked the intake a million times for leakes only thing different now is the cap plugs an wires witch im chageing to night . would the problem have anything to do with the single plane intake please help

 

[sickolds]

are you people for reals look dude the carb is not to big. turn the set screw all the way in then turn out 1 1/2 out each and that should be good

 

[sickolds]

and there is nothing wrong with your des. you can also set the exel. pump it has a link with 3 lil holes take it down one

 

[sickolds]

look dude go here http://www.hotrodders.com/ there is better tec. help there dont get me wrong i love the g body fam. BUTT the tec. help needs to step it up a lil