confusion about the HEI Relay

[Bootybandit]

I have an HEI dizzy that I installed using the old green wire constant 12v supply.  Is it necessary to use a relay?  From what I understand from reading is that it just supplies consistent 12v that my green wire doesn't? I've run it like this for a couple years now before it sat up.  If its an advantage I would like to do it, but Im confused at the diagram in the how to.

30amp to battery
87 to power of Dizzy
85 Power in from RUN power
heres where im confussed
86 to ground?
87a to nothing?

[85lebaront2]

The problem is Government Motors used a 12 or 10 ga wire to power theirs, Ford does not have an ignition feed wire of that gauge. The wiring on these trucks was apparently designed by the 3 stooges.

I have even addded a relay to a Chevrolet C10 that was converted to HEI using a later GM unit from a 250ci 6 cyl. on his 230 ci engine. The factory ignition feed for it was a 16 ga wire so I added a relay and fed it from the starter solenoid stud where GM draws their feeds from.

[ArdWrknTrk]

There is a convention to "Bosch" cube style relays.
Terminal 30, fused power.
87A power out unless triggered.
87 power WHEN triggered.
85 trigger
86 ground for trigger.

Does this help?

[Bootybandit]

Ok got it all worked out Thanks for all the help. The idle is higher then it was before is that normal?

[Gary Lewis]

The guys gave you good advice.  Glad you got it fixed.

As for the idle, you probably had really weak spark before and should now have a very strong one.  That could improve the idle speed by lighting off the mix more reliably.  And it may also improve the power and MPG.

[ArdWrknTrk]

Agreed with Gary!  👍

You probably need to warm it up and set the curb idle according to the radiator support sticker.

[Bootybandit]

Ok did that, I set the timing to 10 BTDC as per the sticker Im assuming this is correct even with a HEI. And set the curb idle to 750 It doesn't seem to wanna go any lower like 650 which is what the sticker says, gets pretty low with the AC on but Im happy so far.  

[ArdWrknTrk]

Do you have a vacuum gauge?

You could try setting the mixture for highest idle.

If the cam timing was straight up I'd say try advancing the ignition to 12-14° BTDC

[Bootybandit]

What do you mean If?  Should I keep it at 10?
I do have a vacuum gauge.  You talked me into it.

[ArdWrknTrk]

I don't know what timing set you have in your Bronco.
"If" as in if it has a proper straight up timing chain, then you can consider advancing the ignition timing for more power.

But you don't have an ignition module that automatically retards the timing while cranking.
That may cause laboured starts and kickback.
It will certainly strain the starter and may hurt instead of help.

There's thousands of members here.
I can't possibly remember all their details, and your sig says nothing about a cam or timing gear set....

[Bootybandit]

I don't even know either, not sure how to tell.  I'll just keep it at 10 but will go to the air fuel and see what I get.  Ive had a hard time in the past noticing the movement on the gauge.  But I do know I can always go back to 1 and half turns if I screw up.  Thanks again for all the help Ill post results.  

[Bootybandit]

Ok this is never ending.  Set the mixing screw from 15 psi to 17 but what Ive noticed.....  Is that with the engine running the throttle won't snap back all the down and rest on the curb idle screw Only when its off.  Am I crazy?  Its very snappy with the engine off but slowly returns with the engine running.

[ArdWrknTrk]

Bill Vose is our resident carburetor expert.
I will ping him....

I can tell you that GM did have a 5 pin HEI module with retard
You can use the (I) terminal of the fender mounted starter relay to trigger it.
They were found in 1980 Toranado's...

[ArdWrknTrk]

I've been thinking about this...

You say you can only get 17" of vacuum but the throttle won't close while running, and the engine won't idle at 650 like it should.
Your build includes HEI, heads, headers, an Edelbrock intake and a 4160 carb....
(no mention of cam, compression ratio, carb CFM, model of intake, primary and collector size or muffler and tailpipe diameter)

We definitely need more information before trying to tune a vehicle over the internet.
Pretend we are completely blind... because basically we are!
Did you buy the Bronco with all this installed?
If so, can you ask the previous owner about it?

Low vacuum and not wanting to idle down sounds like a mean cam, or a massive vacuum leak!
But, that kinda precludes the part where there's so much vacuum that the throttle won't close while running.
Is the carb warped from over tightening?
Have you tried adding a second/stiffer throttle spring?

Hopefully Bill can chime in about your carb tuning.

[85lebaront2]

Jim, there are some strange goings on. I can't fathom a reason the throttle is staying open at idle, unless he has a cruise control with a leaking valve in it. If he has cruise control, I would start by disconnecting it from the carburetor linkage.

If the throttle is part way open, the idle mixture screws won't have much if any effect.

Saying he has a Holley 4160 is like saying he has an AFB or AVS or 4GC or Quadrajet. It is simply a model number. I have a 4150, model, list number 4609, Ford PN C9AF-9510-U which happens to be a 1969 428 CJ carburetor for a vehicle with a C6.

[ArdWrknTrk]

I get it.
Simply disconnect the bead chain.

I also understand "4160" can be anything!
What would help is a photo of the build & list #'s on the front of the choke horn...

[Bootybandit]

I bought the truck and drove it home and had now idea what had been done to it.  I just replaced the holley 4160 with a Carter AFB.  I put the headers on because one of exhaust manifolds were cracked and the headers here actually cheaper.  As far as what's been done to the motor I have no idea.  I was just hoping there was a reason a carb would not close when running but would close when off.  Could be the throttle spring needs replacing.  It is pretty old.

[ArdWrknTrk]

Okay, so it has an Edelbrock and not a Holley?  

There should be numbers stamped on the base flange near the passenger front bolt.
Can you tell us what they are?

Is there any way to ask the old owner what they did to the engine?

[ArdWrknTrk]

I can buy CI Windsor manifolds all day long for $45-50 + $19 shipping.

You must have found quite a deal on headers!    

[Bootybandit]

I bought the Holley and manifold combo from Summit.  The manifold is a Summit brand I'll check the numbers on it.  My current AFB carb is # H1 9627S