1406 hesitation.

Hey guys I need a little help with my edelbrock 1406. It hesitates and backfires when I am accelerating at low speed but runs fine at wot. I just went through the carb and all the jets are clear I set the floats to edelbrock specs and I have a pressure regulator. Someone said I might need to advance the timing? Any suggestions
Thanks

 

is it backfiring through the carb or exhaust?

 

Makes a poping or pinging sound not a real loud backfire

 

You know my buddy has that same carb on his 327 that sits in his '52 chevy. I think he may even have the same issues, going to look at it this week end.
I'll be keeping an eye on this thread.
My self I think it's a pile of junk.


You know, my buddies car ran great until one day the carb stuck at wot. No visible reasons, internal issues.

 

what pump setting is it at, whats your fuel pressure, and what timing do you run? I had two 1406's on a 355 that ran GREAT!!! it took work to get tit there but it was a holy terror all the way through the RPMs, I'm sure we can get ya squared away

 

I like the sound of bumping the timing. How about the air/fuel screws? I was curious about the base setting on those.

 

Could it be a lean misfire?

 

The regulator is set up at 4 1/2 lbs I know it can take more but the reg is a cheap thing so I don't believe the settings

 

Generally I run those at all the way in then 2.5-3 turns back out that is the standard factory setting from edelbrock

 

Cool, that's pretty much what I thought.

 

ok is it one of the cheap dial regulators from RPC or Mr Gasket... I've seen those piles be set at 5 and be around 9psi on an autometer gauge lol i run the holley 12-803 or an Aeromotive style regulator

 

I'd think you could go a little higher. What should it be?^^

 

and 52pig I agree another thing is could it have too much timing so its detonating instead of being an actual carb issue?

 

Sounds like either timing or valve lash, if you know the carb's set up OK.

 

I am starting to agree with the timing.

 

Well I took the idle screws out a little further and it's doing better still backfires through the carb sometimes under load, going to adjust the timing too.

I have a power glide question. I have a linkage that comes up just to the drivers side of the dizzy and connects to the tranny just above the gear shift.any ideas?

 

The idle mixture screws only set fuel air mixture at idle. Above that you are working with the springs on your metering rods.Heavier springs slow down the secondaries and lighter springs make them come in faster.
I would guess if you are getting a ping at "tip in" your timing is a little too far advanced,a backfire is likely retarded timing. put a light on it and see where you're at.

 

Stock engine, or what other mods have you made?

What's the TOTAL ignition timing (initial+centrifugal+vacuum advance if so equipped)?

How much manifold vacuum at idle and cruising speed?

Are the metering rods and power pistons moving freely in their bores?

Are any of the plug wires bundled closely together for any length?

 

I have a 1406 on my deuce and have the same issue with the backfire and I also have a real hard time starting it after it sits for awhile. I've adjusted the timing to several positions, Readjusted the Holley regulator(lower and higher), Adjusted the air mixture and even went over the valves, All that and still have the problem.

With that said it was suggested to me to replace the carb with another 1406 however with cash limited thats gonna have to wait a bit. Apparently some of these model carbs have metering flaws that Edelbrock won't admit.

 

In my first post I talk a little junk, but I do agree that some seem to have flaws. I personally rebuilt my friends engine, he brought it to the shop and I tuned it. Was running beautifully until...it stuck at 3/4 throttle on the highway. We pulled over and there were no external issues. I backed idle all the way out and nothing.
Now, nothing but issues, sputtering at initial throttle, stalling in gear.
I've banged my head a couple times dicking with the car to no avail, that's why I'm watching this thread. I tune old cars all the time and have never had this much trouble. And like above he doesn't have the money to buy a new carb right now.
It has to be the part.
So has the OP found his solution?

 

I had a 625 Comp Series AFB do that once, but it was on a cold damp morning and I had cold air intake via hood scoop on my Duster. I pulled over, popped the hood and the carb was iced. In about a minute the heat from the motor thawed it out and the carb snapped closed. I stuffed a rag in the scoop and kept going to work, no further problems.

There used to be a machining problem on some of the 500 AFB's where a passage wasn't drilled deep enough and there was a transition problem from idle, sounds like edelbrock might be having a similar issue.

Basically if the timing is right, you have cleaned the carb, set the floats and made sure everything is kosher in assembling the carb, I would try another carb to see if it is engine or carb.

 

I installed a 1406 carb on a 327 and a Pertronix distributor / coil at the same time. Sometimes under a little load it would backfire up the carb. I advanced the carb a little bit three times and the backfire went away for a little while and then would backfire again. One evening the car just died with no warning. The coil had gone bad. I replaced the coil and it has never backfired again. I have had very good luck with the edelbrock carbs and this was the only time I was thinking there was a carb problem, but my doubts were misplaced. Be sure all ignition parts are in good condition before replacing carb (cheaper fix).

 

You didn't say what it's on, (or I didn't see it) what motor, cam, distributor, headers, etc.
1406 is a "lean" version of a 1405 so it might be too lean for headers, but I'd suspect your timing is the culprit.
Does it also do it when it's cold and the choke is still "on"?

 

Just install a heat insulator block between the carb and intake. Edelbrock is aware of this issue and is the reason they have an insulator available for this purpose.

 

Edelbrock sells a calibration kit #1487 for your carb. Sounds like you have to richen it up.

 

Elcamino65 ,did you just get this running or was it running good before,the reason I ask is that I am wondering what kind of intake you are using.Everyone probably knows this already but edelbrock carbs work great on late edelbrock intakes but some early intakes required that thin sheetmetal spacer between two gaskets ,I had this backfire ,hard restart,glowing header prob on my 27 with an edel.dual plane ...pre performer era intake,kinda looked like a psuedo spread bore /square bore intake .really resembled the newer performer types now made.
I have a 1405 on my 55 f-100 302,no probs,a 1407 on my 65 galaxie no probs ,twin 1405s on my 27 no probs for 12 years.I guess Ive just been reeeel lucky.

 

4 1/2 is plenty. between that and maybe 5 1/2 for an Edelbrock

Dickster's spot on, the insulator is a good idea, but the timing could be an issue as well, and should be verified. Then think about metering rods and springs.

 

Oh man, I don't wanna think! Set it and forget it! right?
But really, don't mean to highjack the OP, I'm going down to check out my friends car this weekend. I am throwing a spacer on it, he actually has one for the intake.
And I'm taking my timing gun!
Once and for all! Done.

 

Sounds to me like a "lean" pop and ping.........

 

Me and another guy got in a heated argument with a so called Edelbrock tech at a Goodguys event last fall over the hard starting issue, He insisted they they weren't aware of it. However I do have one already and it didn't help much.