Edelbrock 1406 Question

[YellowRose]

Can those of you who have recently installed an Edelbrock 1406 on your engine answer this question? There is a front and a back connection for the distributor vacuum connection. The manual says to plug up the one you do not use with the screw in plug that comes with the carb.

Which one did you attach your distributor vacuum connection to? The front or the back??

Good Birding!

[Guest]

Front left

[YellowRose]

Edelbrock 1406 Question

Hi Tbird8!

Thanks for the reply. Front left as in standing in front of the car looking at the front of the carb? Passenger side or drivers side? You screwed the black plug into the center rear port, right?

[Guest]

Yep You only need that small one in the front. We don't have alot of vac. acessores on these.

[byersmtrco]

Confirm that

[YellowRose]

Edelbrock 1406 Question

I should have thunked out my question better before I posted it... I may have put the vacuum hose from the distributor/vacuum advance module on the wrong side in the front of the carb.

Should it be on the connector on the drivers side? Or the one one the passenger side? I screwed in that black screw in plug into the back center port... Did I set mine up wrong?

[byersmtrco]

Ok, so mine is older, but the 1406 on my 65 was the same set up. Vac port rh (pass) side frt goes to dist vac/adv. Other side is plugged off. Vac port rh (pass) rr is for choke pull off.
I am thinking the plugged off port would be for a later model with a thermostatic air cleaner (flapper valve in snorkle)
I believe my 65 had that and it was either locked open or the flapper itself was removed (can't remember)

The 1406 on my 72 El Camino had 3. 2 were plugged off, I had the open air cowl set up on that.

Make sure you have your choke on a more lean setting. It's those 3 set screws (torx) and counter clock wise to the last line. The dirrections are pretty straight fwd.

Actually my (older) Carter/Edelbrock (model # 9637) is a 635 cfm.

Same thing diff # !!! The 1406 is a more refined version.

[Guest]

Ray I used the Vac. port on the front drivers side
Bob M

[Guest]

Hey sarge you want ported vac not direct. So looking at the front of the carb! the left seemed to be ported to me and the right one direct. Seems to work. We don't need the hole you put the black plug in unless you want to put your brakes to it. But that's already hooked up. Take that thing and RUN it. ......................Bill

[YellowRose]

Edelbrock 1406 Question

Thanks for the replies. I have mine on the left (passenger) side also. I just wanted to make sure that I had it on the right connection.

I am still having a problem with slow acceleration. It will hardly go when in gear. It is sluggish like all get out, though the rough idle problem seems to have been solved by putting new spark plug wires on. It just does not want to go. It dies, sputters, and cuts out when you try to accelerate.

I am still only getting, at the most, 3psi out of the new fuel pump, which is the right vacuum fuel pump for this Bird. This fuel pump is a brand new one from Bird Nest. So I had an universal electric fuel pump installed. It is a nice installation, insulated on a rubber pad, to cut down any noise. Now I get a constant 5+psi and pretty much a full fuel filter of gas. We thought that might be the problem with the sluggish acceleration, not enough fuel pressure and gas to the carb. Apparently, not.

After much poking, prodding, consulting with others, testing, timing checks, (timing is on the money), it is thought that maybe the previous owner might have the distributor off by a gear tooth. Or the rubber between the harmonic balancer has dried out, allowing the two sections to have slipped a bit. Or that there might be something wrong with my Pertronix Igniter II. So we are going to follow Alexander's suggestion he gave us a couple of years ago, and time it by vacuum (if I have this right). Advancing the timing to a higher setting until the engine starts to ping under acceleration. Then back off just enough to stop the pinging.

If that does not fix anything, I am going to have the Pertronix taken off, and points and condenser put in, and set right. If that does not fix it, I am going to have a new stock coil put on, and see what that does. If that does not fix it, the next step might be to pull the distributor and look for a bent shaft, or worn gear teeth. If I have to, I will replace the distributor.

I have been reading the book on causes of poor acceleration. One of the things it talks about on the 352 is the exhaust gas control valve being inoperative or sticking. Where is this valve at and how does one check it? This has not been checked, to my knowledge. The spark plugs are new and have been set to .035 gap. Another cause, is distributor not advancing properly. It could be that. I dunno. I doubt it is anything to do with the fuel/carb now. The carb is new and has not been tinkered with. A transmission tech says the transmission is fine, so that does not seem to be the problem. An engine tech says the engine itself is really good. Any ideas on what else to check? It was so bad he could hardly get it up the incline onto the lift! He had to restart it several times just to get it up that slight incline. I guess he could have set the idle a bit higher, but it is set at where it should be, so I am told.

I am sooo frustrated about this. Just when I thought I had problems regarding rough running in gear fixed (and I do, it seems) I still have this problem of poor acceleration. If the things above do not fix it, you might find it on eBay!

Good Birding and I wish the Thunderbird God would send some of that my way!

[byersmtrco]

1st off, the sluggish part isn't the carb. You need to be sure the dist timing is right. That also means the valve timing has to be right. Timing chain? Excessive wear, or it's jumped a tooth. Eliminate those 1st.
Make sure the rotor is on #1 when the piston is at true TDC.

Quick note; the vac port on mine RH (Pass) side is ported vaccum.

Next, make sure your advance mechinism in the dist is working properly.

It sounds like you have ignition issues. Check for voltage drop. Make sure you're getting 12+ to the poss side of the coil (Run a wire direct if you have to. By pass the ign switch.

If all that is working right, you should be able to just tap the gas and even a 352 will jump all over itself gettin' out of the way.

[YellowRose]

Edelbrock 1406 Question

Hi John,

Thanks for the help. Nope, it does not look like the problem is the carb. I am being told that they dont think it is a problem with the timing chain. It might be a problem with the dist. shaft being off a tooth. I dont know if the previous owner might have pulled the dist and put it back in a tooth off. How does one tell if the rotor is on the #1 position at true TDC?

Thanks for letting me know that the vac port on yours is also on the Pass. side for ported vacuum. That is where I have mine at.

As for the vacuum advance cone, when you take off the vacuum tube to it and suck on it, that section inside the dist. moves. So, from what I have been told by ya'll here, by posts by Alexander, and by others, if you have movement of that mechanism when you suck on that tube, the vacuum advance is doing its job. It is a new vacuum advance module.

As I recall, when the mechanic was checking voltages, from the by-pass or ballast resistor (if I have that named right) mounted on the drivers side by the master cylinder, one lead gives us 9.3v. The other is 12.3 or 12.4v. When you take the measurement at the positive side of the coil, you get 9.3V. So I gather that one of those two leads, the one reading 9.3v, is hooked through the wiring harness to the + side of the coil. Or the 12V connection is, and for whatever reason, along the way, is losing about 3v.

The coil is a fairly new looking 12v (I think) ACCel coil. It is my understanding that reading of 9.3 at the + side of the coil is okay, that it is not to low. So I am confused if I should have something around 9v or 12v. I can tell them to find 12v from some other place than the ign switch and run that directly to the coil to see what happens.

Can anyone tell me about this exhaust gas control valve being inoperative or sticking. I just did a search on it and read the manual also. The book says it is at the outlet of the right exhaust manifold. Alexander said to rev the engine and watch the external counterweight on the exhaust gas control valve. It should move a quarter turn if it is not stuck. It seems to me that I have read in some past posts that this exhaust gas control valve on our Tbirds was one of those often occurring problems that can give us a lot of difficulties. If I remember, the posts said they were prone to sticking.

Thanks for all the advise. Anything anyone else can contribute would be greatly appreciated. This is getting to be a pretty bad pain in the butt for me. I like things working right, and this is sure preventing me from driving this car. In fact, just getting it in for service was a trip as it stalled on me 3-4 times before I got there. Every time I tried to give it the gas to get away from a stop light or sign, it either tried to quit or did, Luckily, I was able to get it started again and make it to the auto shop. I think the reason why it was not doing to badly before was because my mechanic had the idle set higher to prevent it from doing so. Now the idle is set to a more normal position, I gather, and I am experiencing this problem more.

Good Birding!

[FeFranco]

You have me thoroughly confused, because you seem to be all over the place. First off, sorry for this info, but your mechanic doesn't sound like a mechanic. I hope he is offering cheap advise. John gave you some great advice----------MAKE SURE THE DISTRIBUTOR IS IN THE CORRECT POSITION. Until then, nobody can help you. You will need to find a mechanic that can check the distributors position. It would be easy for a mechanic to do, but hard for us to explain to you. I feel that this is an easy fix, so don't just give that car away yet!

[YellowRose]

Edelbrock 1406 Question

Hi Franco!

If you think I have you are thoroughly confused, you should be in my shoes! lmbo.. I am getting suggestions as to what it could be from different sources. Yes, I think John did give me good advice, and you did also. Come Monday morning, that is what is going to happen next. I now have a mechanic who seems to know what he is doing, and he will do that next. In fact, he was about to do that on Friday, but we ran out of time. As little as I know, I also think this problem is related to the distributor, in one way or the other.

[FeFranco]

It might even be a hairline crack in your distributor cap, but you have to check for proper position of that distributor. GOOD LUCK!