Dialing in a new DS2

DoctorC

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Hi All, (sorry for the long read)

So I've installed the DS2, curved by wsa11 (thanks Bill!) for my street use. After a couple conversations with him, and some reading I've come to the following understanding of timing advance. But something is off. Hopefully you can help.
For the tuning, start it up and let her warm up. Once warm set the timing advance with the vacuum unplugged from the distributor.


  • The ford manual for the 67 Mustang (AT) says to set advance @ 12 degrees in drive.
    Ive read that with DS2, add 5 degrees to stock max = 17degrees
    The MSD manual says to set the plugs at 45-55 gap, so I set 54
    Bill set my distributor @ 18 degrees initial advance
    Curved to about 36 degrees max
    (was still using the 1bbl carb)

When I set the initial advance in park (I'm solo) at ~650 RPM the engine runs rough at 17 degrees. Worse with less. Happy point is around 20-24, where she runs smoothest. Ok, set to 17 degrees, plugged in vaccum port and went for a drive.

All was ok, except at WOT I get what sounds like a buzz. I'm assuming this is detonation. I stopped doing that. In drive, stopped, the idle was very rough and shaky. But it ran. So I installed the Weber 32/36 last weekend. It's in and running, but pretty rough. Once I get the gas pedal hooked up and the fuel regulator installed, I'll try and dial it all in.

My understanding of advance is that:
  • Initial advance (18 degrees)
    is added to measured advance (17 degrees)
    This gives 35 degrees advance at idle?

This seems a little excessive. Am I misunderstanding something? Dialing in the Carb and DS2 together is going to be a PITA if I don't get the theory down. VI ships the Weber jetted already, so hopefully that'll not be an issue.

Thanks in advance!
 
What grade of fuel are you running??
There should be 14 degrees of vacuum advance on your DS11.
When you point the timing light does the mark on the pulley jump around or is it steady??
 
It's sounds like maybe you have the idle set a little low, should be 525-575 in drive. Maybe a bit more if it helps. You didn't mention adjusting the idle mixture screw(s). Did you?

At 17 degrees advanced w/ the curb idle set and idle mixture screw(s) adjusted properly(lean best idle) and it's still running rough you either have a vacuum leak somewhere(pvc, brake booster, bad port caps on unused vacuum port(s), bad vacuum modulator in the transmission, bad hose, bad connection(s), bad carb flange gasket, ect), ignition problem(misfire, bad plug/wire, cap/rotor issue, weak coil ect) or a problem with the carb/fuel.

I've never ran an MSD CD ignition box so I may be out there, but .054" gap seems pretty wide to me.

Are you using ported vacuum or manifold vacuum? You shouldn't have any vac advance in at idle if you're using ported vacuum. And having full advance at cruise is a good thing. Iow, little mechanical, alot of vac advance and your initial timing when cruising like under light throttle. Do you have a dial back timing light?
 
wsa111":2bs4mg86 said:
What grade of fuel are you running??
There should be 14 degrees of vacuum advance on your DS11.
When you point the timing light does the mark on the pulley jump around or is it steady??
I'm on regular gas. And the card you sent with the DS2 said "18 degrees initial" , so I assumed that was the advance?

Econoline":2bs4mg86 said:
It's sounds like maybe you have the idle set a little low, should be 525-575 in drive. Maybe a bit more if it helps. You didn't mention adjusting the idle mixture screw(s). Did you?

At 17 degrees advanced w/ the curb idle set and idle mixture screw(s) adjusted properly(lean best idle) and it's still running rough you either have a vacuum leak somewhere(pvc, brake booster, bad port caps on unused vacuum port(s), bad vacuum modulator in the transmission, bad hose, bad connection(s), bad carb flange gasket, ect), ignition problem(misfire, bad plug/wire, cap/rotor issue, weak coil ect) or a problem with the carb/fuel.

I've never ran an MSD CD ignition box so I may be out there, but .054" gap seems pretty wide to me.

Are you using ported vacuum or manifold vacuum? You shouldn't have any vac advance in at idle if you're using ported vacuum. And having full advance at cruise is a good thing. Iow, little mechanical, alot of vac advance and your initial timing when cruising like under light throttle. Do you have a dial back timing light?

I was thinking of dialing back the plug gaps. Prob back to 40, just to be safe. I havent mucked with any of the idle or mixture of the Weber yet. It's just bolted down and hooked up is all. That's next, but I'm hoping to start at least with a good advance point, to not worry about the DS2. I bought a Vacuum guage to help with all this... dont know where to hook it to yet tho =)
 
Id do what Econoline said and check for vacuum leaks. Go to town with starter fluid and see if it stumbles. Check all the places he mentioned
 
Stock camshaft?

I run 12 degrees timing with rpms up about 750-800 with my cam 264/274/112.
Plug gaps at .050.
 
Plug gap .045"-.048" is what you need.
When you put the timing light on the pulley is the mark steady or does it go spastic.
If it goes spastic you have the polarity reversed to the MSD from the DS11.
Did you get the MSD-8869 harness which connect directly to the box??
As post before check for vacuum leaks.
Till you get it dialed in go with a higher octane fuel.
 
Not spastic, I bought the harness you recommended and I think it only hooks up one way.
I picked up a Bosch timing light that's multi-spark compatible, so I'm steady on the flashy-flashy too. Good call on the high octane fuel. I'll do that. I have an almost empty tank because I wanted to install a fuel sender that had a return line. I think i still may.
 
bump, bump...
ign 1st then carb...
 
chad":79etl2nh said:
bump, bump...
ign 1st then carb...

I hear ya. Once i get my exhaust hooked back up (i had the darn gasket in my hand last week while in the garage!! It's disappeared, prob went to that place with the lost socks...) I'll dial back in the distributor. Your definitely right tho, ign 1st, carb second.
 
Update:
I got the Dizzy set to 14 degrees advance and the idle is smooth and nice.

A couple questions tho:
1- The electric choke on my weber 32/36 never turned off. I'm powering it from the 12V line that used to go to the coil. So it's a switched 12V from my understanding. The radiator got hot, so it got up to temp? I rotated the bar connector for the choke signal (12V) 180 degrees, is there an internal mechanism I might have broken?
2- The PCV in is smoking a lot. Is there supposed to be lots of fumes in the valve area? I have the PCV return hooked up to the Carb, but since I was running no filter, the input was open and spewing fumes.

I setup the Carb to an idle of about 700rpm in Park. Pretty smooth. Idle mixture is at 2 turns out with the jets as shipped from VI. I will have to take it out for a spin once I figure out how to hook up the gas pedal =)
 
“…I'm powering it from the 12V line that used to go to the coil…”
Some use the lug off the alternator as it’s the correct voltage.

“…is there an internal mechanism …”
The black cap contains a coil spring. I don’t think you can break it by twisting, but they don’t usually get set off the middle (look 4 little hash marks on there) by much (middle is the long mark in ctr).

For the PCV system I would call them both “in”. The rear pvc itself can go on the ported or manifold vacuum I believe. The front, above the carb, into the air filter for the carb. Not sure what the Weber has for an a/f canister. “Extra smoke” can be a sign of ‘blow by’. Congrats on the Closed System PCV attempt.
 
DoctorC":25qnftg2 said:
Update:
I got the Dizzy set to 14 degrees advance and the idle is smooth and nice.

A couple questions tho:
1- The electric choke on my weber 32/36 never turned off. I'm powering it from the 12V line that used to go to the coil. So it's a switched 12V from my understanding. The radiator got hot, so it got up to temp? I rotated the bar connector for the choke signal (12V) 180 degrees, is there an internal mechanism I might have broken?
2- The PCV in is smoking a lot. Is there supposed to be lots of fumes in the valve area? I have the PCV return hooked up to the Carb, but since I was running no filter, the input was open and spewing fumes.

1, When you turn the choke thermostat housing in the direction of the choke blades closing it should close the blades and then open them when turned the other direction. If not, you should pull it off and make sure the little loop on the end of the bimetal coil is attached to the choke arm inside.

2, What is the condition of the engine? Is it a very recent rebuild? If it was recently rebuilt the rings may not be fully seated yet. As far as the "input" fuming, it shouldn't do that if the PCV is hooked up to manifold vacuum b/c it should be putting the valve cover in a slight vacuum.
 
chad said:
“…I'm powering it from the 12V line that used to go to the coil…”
Some use the lug off the alternator as it’s the correct voltage.quote]
If you use the stator terminal its only 9 volts.
If you had a holley or an autolite carb, ford did make a choke housing which was compatible with 9V.
I mentioned holley cause i believe the Ford thermostat would fit.
You always could use a relay from the stator terminal to trigger 12V to the choke coil.
 
Thanks for the suggestions. I'll pull a 12V off the alternator.
The PCV "out" has a collapsed hose it seems and is not pulling a vacuum. I'll replace this and see how things go. I bought a compression tester to have an idea how the chambers are. I'll prob get to that next week. The PO did not know if the engine is rebuild or not. Peeking through the spark plug hole, the cylinder heads are clean as whistle, and when i bought it my mechanic said the oil pan was sludge free and the engine looked good. So I'm hoping that means 60K on the engine, not 160k.

Issues:
So yesterday, after dialing in the dizzy at 14 degrees, I wanted to tune the carb. So i hooked everything up and it ran like crap. Backfires, blow through the carb, i thought the engine was going to fly out of the bay it was so shakey. All this at idle.

Turns out the vacuum advance from the Weber is too strong. I pulled the advance and it runs great. Put my finger on it and it sucks like a hoover. Should i just leave it disconnected?

Thanks,
Roger
 
"...I'll pull a 12V off the alternator. ..."
again, I'd use less. The lug may B labeled right on the case "STAT" for stator.
I put a lill inline fuse in there (not needed) just incase...
 
DoctorC":25zyiakc said:
Thanks for the suggestions. I'll pull a 12V off the alternator.
The PCV "out" has a collapsed hose it seems and is not pulling a vacuum. I'll replace this and see how things go. I bought a compression tester to have an idea how the chambers are. I'll prob get to that next week. The PO did not know if the engine is rebuild or not. Peeking through the spark plug hole, the cylinder heads are clean as whistle, and when i bought it my mechanic said the oil pan was sludge free and the engine looked good. So I'm hoping that means 60K on the engine, not 160k.

Issues:
So yesterday, after dialing in the dizzy at 14 degrees, I wanted to tune the carb. So i hooked everything up and it ran like crap. Backfires, blow through the carb, i thought the engine was going to fly out of the bay it was so shakey. All this at idle.

Turns out the vacuum advance from the Weber is too strong. I pulled the advance and it runs great. Put my finger on it and it sucks like a hoover. Should i just leave it disconnected?

Thanks,
Roger
Roger, try 17 degrees initial advance & see how it performs.
You can try to hook up the vacuum advance to ported vacuum.
See if it performs ok. Let me know. Bill
 
Weber had the bowel vent on the top of tge carb blocked off in European cars. You need to use the under carb PCV system.

Never hook the PCV to a Weber carb. It has to use an air cleaner suction source, and under carb suction source, and single or two peg TVS valve to balance the right flow.

Other ways exist to do the same job, but the Weber is very much an air flow emulsified carb that is a true spazin' out child that needs a specific firm but gentle hand to pull it into line. Adding the line to the carb makes everything ignition, fuel and vacuum related go to heck.
 
Oh, that's good info. Thanks for that. But what do I do now with that intake just leave it open or plug it off?
 
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