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Rebuild busted Eddy 1407 vs upgrading..

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SafetyHelmet

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Hey all,

Been a while.. new job has had me super busy. I am here to ask what is probably a pretty commonplace question-

Background: My 82 Jimmy has a 454, I think from a mid-late 70's suburban. Paired up with a TH350 and NP205. D44 front, 14-bolt rear. On top of the motor is a 600CFM Edelbrock 1407, but the electric choke must have been busted at some point, as it's rigged up as a manual choke. So, it's basically a 1406.

I've gone through it once and cleaned some gunk out, and it runs okay once the motor is fully warmed up. Until that point it stumbles badly when you push on the accelerator. In fact if the motor isn't totally warm, you're likely going to kill it by pressing on the gas. At any rate, I have been considering just picking up a shiny new Holley 4160, which is 750CFM, street tuned, and has electric choke. I really don't mind the manual choke, but if I was gonna upgrade, my thinking is I might as well not have to hassle with it since the price is about the same.

Long term, I will wake the 454 up a bit, the eventual goal would be to get around 600 HP out of it, but not for a long while since I have plenty of things to fix up before that. When the truck is further along, I plan on taking it to some shows.

Thoughts?
 
I wont argue a Q-jet is probably better--personally I dislike Holley carbs,9 out of a dozen I've had were nothing but greif...


Edelbrocks tend to run lean,and also "cold"--ones I've had actually frosted up on chilly damp days and refused to idle or accelerate good until you drove it a good 20 minutes often--if the carb has a spacer or adapter under it,or a thick insulator gasket,it'll block the heat from the intake and can cause that or aggravate it...

Also if your using a stock intake meant for a Q-jet,with an adapter,be sure the gaskets cover the manifold and carb base fully,and aren't letting a vacuum leak occour..(very common!)..that will raise hell with idle and acceleration,especially when its first started cold..


I had to make the heat riser on my exhaust stay closed all winter on one 305 I had with an Edelbrock so I could drive it in winter without the carb frosting up and stalling at every stop...I hooked the vacuum hose to a manifold vacuum port to do that..if your engine has no heat riser or has an aftermarket intake,there might not be any heat passages casted into it..then you'll just have to live with it running crappy when its cold till it fully warms up..

It sounds like maybe the accelerator pump isnt shooting enough fuel too --maybe its piston cup is worn out or the stroke is too short,there is three holes in its lever you can move the linkage too,to give it more or less stroke..seeing its manual choke your also probably opening the choke too soon ,making it run lean and want to snuff out under acceleration..

You might want to check the timing too,and make sure the vacuum advance is working,hooked to the proper port on the carb,and the mechanical advance weights are free and working too...some engines like the timing advanced a bit over stock settings with todays gas also,which improves acceleration response..
 
Can you get a Q-Jet new, or would I need to track down a used/rebuilt one?

I believe the motor is stock aside from the Edelbrock carb. I'm hooked up to manifold vacuum, and I am almost entirely certain the accel pump isn't shooting enough fuel- but before I went and tried to rebuild things and horse around with it, I am wondering if just replacing it outright with a different carb makes more sense. Also, if another carb will give better performance potential as I modify the motor later on, I'd rather buy a new carb once, and not need to upgrade again later.

Thanks for the feedback!
 
Awesome, thanks Ryoken!

Regarding gaskets for the carb.. if I want to pop my current one off to have a look at coverage, thickness, etc, I assume they're reusable as long as you don't tear it or otherwise mess it up when removing the carb?
 
eh, sure... but I wouldn't be taking stuff apart, just to check that...

you can use ether, propane or carb cleaner to check for vac leaks around the base.. (ether and propane revving it up, carb cleaner stalling it)

and if it's not stalling at idle, it doesn't have a vac leak... and there's no need to "check" the gasket, but yes, it can be reused if unmolested...



keep in mind.. different carb architectures have different strengths/weakness's, but generally ALL CAN BE MADE TO RUN REASONABLE, if they are working correctly..

which is the case, 98% of the time, that they aren't functioning 100% correctly.. not that a holley, quadrajunk or carter are a POS, more usually slandered due to owner idiocy...


that said, quads, and that architecture, tend to be one of the more "stable" carb platforms... carters have MANY more parts to fail, and holleys can't keep a tune to save anyones life usually..
 
Yeah, once she warms up there are really zero issues with idling. Really, it idles fine cold with the choke closed as long as you stay off the gas pedal entirely.

Thanks again for the advice. I have basically zero local resources in terms of brains to pick; this forum and you guys being willing to help us newbies out is invaluable!

I'll look into the quadrajet option some more.. it's a little bit more expensive, but less messing with a fussy carb on the Jimmy means more time spent grinning while driving it!
 
sure, $200 is pretty affordable, pushing 400 gets a bit more "life intensive"... :haha:


any questions, holla... even tuning, tweaking, diagnosing your existing stuff, shoot me a pm...
 
I'm gonna go with the Q-jet after doing some more reading and considering options.

Followup question: would it be worthwhile to upgrade the intake manifold at the same time, or is that only worthwhile if I'm changing the cam, heads, etc?

Thanks again guys!
 
is it a stock intake with a adapter on it now?

keep in mind, your going from a square bore, to a spreadbore carb.... you'll either need an adapter plate, or buck up for a new intake...

generally I would say not to bother if you where staying square bore... not worth it, unless like ya say, you where doing new heads, cam, etc.. but the spreadbore aspect adds a little incentive to going for an intake as opposed to a $30 adapter...
 
Good question.. is the 1406/1407 always square bore? I'll go in the garage and see if it looks like there's an adapter plate under it.
 
post a pic of the intake/carb.. afaik, it should be a square bore... the only spreadbore eddy's are the quad replacements they make... iirc, that's a 1904...
 
I think there's an adapter! At least, some kind of metal plate between the carb body and the intake. Photos below. So if its a stock intake, I'm guessing it should be spreadbore?

Carb.jpg


IMG_0590.JPG


image_20.jpeg
 
yup... should be a spreadbore under that adapter... there ya go! :D
 
So, no sense in a new manifold I assume? At least, not until I spend the big bucks on motor improvements?

Thanks again! Planning on ordering a Q-Jet tonight!
 
yeah, I wouldn't bother unless you where doing head work, cam, etc...
 
I got my last three q-jets from SMI, Sean builds a nice carb, they have electric chokes and he sets them up per application. Just another source for you if needed.
 
Cool! I try to do business with smaller operations when possible.. I will give them a ring, see if they can help me out. Thanks again guys! Hopefully by early spring the Jimmy will be handling a lot better, and running a lot more reliably.
 
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