abcdefghii
Well-Known Member
Vac advance is disconnected.
If I turn the distributor back towards anything less than about 30° it'll just die.
This again.... 4bbl on a 318 with a 2bbl
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If I turn the distributor back towards anything less than about 30° it'll just die.
PRH
Well-Known Member
Is that because you have the throttle blades closed too far…….in an attempt to lower the idle rpm?
It likely idles high because the timing is so far advanced.
How many turns out are the mixture screws?
If you have a vacuum gauge, hook it up to the manifold vacuum port…….. see what it says as you’re retarding the timing.
It likely idles high because the timing is so far advanced.
How many turns out are the mixture screws?
If you have a vacuum gauge, hook it up to the manifold vacuum port…….. see what it says as you’re retarding the timing.
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abcdefghii
Well-Known Member
Honestly, at this point I have no idea and I'm getting frustrated.
I verified I was on TDC again, made sure plug wires all good. About half a turn out on the mixture screws. Vacuum gauge on the Christmas tree port at the beach of the manifold reads about 20.
Yet it refuses to run any lower than 35-40
I verified I was on TDC again, made sure plug wires all good. About half a turn out on the mixture screws. Vacuum gauge on the Christmas tree port at the beach of the manifold reads about 20.
Yet it refuses to run any lower than 35-40
PRH
Well-Known Member
If the throttle speed screw is backed almost all the way off, the blades are closed too much.
Here’s what I would do next……..
Make sure mixture screws are set two turns out(1/2 a turn isn’t going to cut it)
Start engine, and after it’s got a little heat in it, adjust the idle speed screw to obtain about 16-1800rpm.
Now start retarding the timing, and see how close to 10* you can get before it dies.
As you retard the timing the idle speed should start coming down.
If you get close, you can just open the blades a bit more.
You’re trying to balance the ign timing with the carb opening, to end up with the timing where it should be…… and the desired idle speed.
Here’s what I would do next……..
Make sure mixture screws are set two turns out(1/2 a turn isn’t going to cut it)
Start engine, and after it’s got a little heat in it, adjust the idle speed screw to obtain about 16-1800rpm.
Now start retarding the timing, and see how close to 10* you can get before it dies.
As you retard the timing the idle speed should start coming down.
If you get close, you can just open the blades a bit more.
You’re trying to balance the ign timing with the carb opening, to end up with the timing where it should be…… and the desired idle speed.
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I wish you were closer. You still have something messed up. Your timing light is hooked up to the wrong cylinder or something. It might help to start with the idle mixture screws out a turn and a half -2 1/2. Then adjust from there. A half turn is too lean.
I always cringe when soneone says "disconnect the vacuum hose" and never mentions to plug it. It's second nature for us to plug it with a tee or screw, but there's a good chance the guy we are talking to doesn't know that.
abcdefghii
Well-Known Member
The thing I think that's going to cause me an issue getting that far, the vacuum can on the side of the distributor will contact the firewall and not rotate any further. I'll try in a bit though, one more attempt today before I say "f this"
Yeah, I'm starting to wonder if there's someone in VA who can help me with this as I'm sure it's something obvious.
Made sure light is hooked up correctly and the the clamp is facing the right way.
I have little vinyl caps I use on both carb and distributor to plug it.
PRH
Well-Known Member
If the dist can’t be rotated into a position where you end up where the timing is “normal”, it’s clocked wrong.
But you can still do the test and see if you can get closer to getting things ironed out.
If it seems you’re on the right track you’ll need to pull the dist and rotate the gear a tooth.
But you can still do the test and see if you can get closer to getting things ironed out.
If it seems you’re on the right track you’ll need to pull the dist and rotate the gear a tooth.
Well now we learning what you know and what you don't. It's frustrating in part because you're doing this by rote. Step 1, 2, 3, and the we're saying repeat 1, 2, 3. I was there. I'm sure many others were there too.
No cap is needed on the distributor. The vacuum is created by the engine. So if you're removing the hose at the carb, just cap that nipple.
The vacuum advance can interfere with rotating the distributor. If this because an issue, the reinstall and move all of the plugs over one spot.
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"The thing I think that's going to cause me an issue getting that far, the vacuum can on the side of the distributor will contact the firewall and not rotate any further."
Easiest way to deal with that is to pull the vaccuum advance forward and then disconnect the plug wires and move them clockwise one hole over. Probably best not to remove them all at once, although that can be done, too, if you can remember 18436572.
Easiest way to deal with that is to pull the vaccuum advance forward and then disconnect the plug wires and move them clockwise one hole over. Probably best not to remove them all at once, although that can be done, too, if you can remember 18436572.
You're right, it doesn't need to be removed if there is room to do what you say.
abcdefghii
Well-Known Member
I owe @PRH a beer.
Turned idle screws out 2 turns, started up, adjusted idle to about 1,500 and then rotated distributor a bit ... Check light.... Repeat, until it's hitting 10°
Idle still high but I noticed the temp creeping up and steam coming from the back of the engine so I shut it off. Inspected everything and see no leaks, nothing wet, could be residue from me replacing the heater hoses, dunno for sure. The thermostat is still weeping a little, going to order a better housing when I get to that.
It fires right back up, almost no hesitation. Just need to get the curb idle back down to a reasonable value next.
Turned idle screws out 2 turns, started up, adjusted idle to about 1,500 and then rotated distributor a bit ... Check light.... Repeat, until it's hitting 10°
Idle still high but I noticed the temp creeping up and steam coming from the back of the engine so I shut it off. Inspected everything and see no leaks, nothing wet, could be residue from me replacing the heater hoses, dunno for sure. The thermostat is still weeping a little, going to order a better housing when I get to that.
It fires right back up, almost no hesitation. Just need to get the curb idle back down to a reasonable value next.
If its not down to 650 or 700 rpm then the timing you are measuring is probably intial+advance.
Lets say you measure 10* at 900 rpm.
And lets say this particular distributor advances 2 degrees between 750 rpm and 900 rpm.
Then initial timing is actually 8 BTDC.
That's just a made up example. I don't know what the advance curve looks like for the distributor you have. You'll have to timing measurements at increasing and decreasing rpms, and then we can figure that out.
Lets say you measure 10* at 900 rpm.
And lets say this particular distributor advances 2 degrees between 750 rpm and 900 rpm.
Then initial timing is actually 8 BTDC.
That's just a made up example. I don't know what the advance curve looks like for the distributor you have. You'll have to timing measurements at increasing and decreasing rpms, and then we can figure that out.
I wouldn't idle it up to 1500 for that reason. Whatever works but I wouldn't. If it won't idle because it's set too slow then increase it but not to the point that it's getting into the advance.
Here's some posts with examples of factory advance and timing for 318. Following posts have snips from the factory tech pamphlets.
[URL"]https://www.forabodiesonly.com/mopa...-duster-backfire-issue.545100/post-1974378937[/URL]
[URL"]https://www.forabodiesonly.com/mopa...-duster-backfire-issue.545100/post-1974378937[/URL]
abcdefghii
Well-Known Member
This is the distributor that I'm running ... PerTronix D141700 PerTronix Flame-Thrower Plug and Play Billet Distributors with Ignitor II® Module | Summit Racing
Hopefully sometime this week I can adjust the curb idle down to a reasonable value without it screwing the timing up.
It will take some timing away but not all of it. Setting timing, idle speed, and mixture is not a set it once and you're done deal. You always have to sneak up on it by adjusting one, then another, and fine tune it all again.
You know you have a dial back timing light don't you?
If it is unknowingly dialed back to 40°? Set the timing light dial to zero.
Try flipping the #1 spark plug wire Pickup Lead for the timing light 180°
It makes a difference for it to read the pulse properly.
.
It sounds like the balancer outer ring has slipped, or you're reading the wrong timing mark.
That could be a definite possibility.
This is another good possibility ^^^^ That's why I don't use a manual dial back light. Too much room for error.
PRH
Well-Known Member
Did you readjust the idle speed screw after the timing was down at 10?
Btw, we don’t know yet if 10 is the magic number, it was just suggested as a place to start.
You could drop it down a bit more, and/or adjust the idle speed screw.
The idle speed screw setting, the mixture screw setting, the timing……. All need to be tweaked together, as a system.
The settings I suggested were just to help get you into the ball park…….. so you can start working on the final adjustments.
abcdefghii
Well-Known Member
Yeah, and I assume I'm using it correctly, but going to just make certain before I do anything more.
Hopefully that's good, the balancer was replaced in October when I replaced the timing chain etc.
I did not, but only because I had noticed the steam from the engine. When I next have time to work on it, I'll start adjusting that down and watching the timing.
It was (is) definitely a good place to start, as I wrote previously the whine fires up almost instantly where it's currently set.
There's no way to know the advance curve without making some measurements.
You don't need to know that when setting the timing at idle, but you do have to keep track of the rpm so you won't be surprised when the timing changes with rpm.
Once you have the initial that runs strong, its essential to check the timing at higher rpms.
Compare those measurements to the examples I linked above. Then adjust the advance curve as needed.
It's the mid and high rpm timing that can damage under full throttle, or make it slow and sluggish.
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