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Vacuum Advance etc...
https://slantsix.org/forum/viewtopic.php?t=13512		 Page 1 of 1
Author:  ceej [ Wed Jun 29, 2005 1:09 pm ]
Post subject:  Vacuum Advance etc...
Put a new timing chain in, and things are much better. I can time the car now. Seem to have a bit of a dead spot/hesitation that wasn't noticable with the retarded timing. (It didn't drive well at all before the new timing set.) It occurs while going down the road at 1/4 to 1/2 throttle.

This is a '74 1bbl 225. When I got the car, the vacuum system was mainly missing. I have the Vac advance running directly to ported Vacuum right now. Unless I really stand on it, there is quite a hesitation when accelerating.
Running no load, I show solid Vacuum advance as the butterfly comes off idle. Can't really watch it whilst scampering down the road. Might have to port a guage in so I can see what's going on.
It's quite possible that my Harmonic Balancer has tweaked itself, so when I get the plugs out this weekend, I'll do a search for TDC. I may not have enough advance at the moment. This car has the original points distributor in it.
I'm just hoping I'm not missing something important.
There is a "Dist" port on the relay/gizmo mounted on the air cleaner. It's got nothing on it at the moment. How does this function? Temperature activated I would think. Hold the advance off till the engine is warmed up?
Since I don't drive the car until the choke shuts off, I didn't think I needed this part in the circuit.

Still Learning

CJ


Thoughts?
Author:  Slant6Ram [ Wed Jun 29, 2005 2:15 pm ]
Post subject:  Good
Quote:
There is a "Dist" port on the relay/gizmo mounted on the air cleaner. It's got nothing on it at the moment. How does this function? Temperature activated I would think. Hold the advance off till the engine is warmed up?
Since I don't drive the car until the choke shuts off, I didn't think I needed this part in the circuit.
Yep, you've answered your own question. You don't ever really need this part.

Glad to hear it's running better. Have you checked it out with a timing light to make sure advance is working correctly? Sometimes they can stick. What is the initial timing setting?

How about the accelerator pump in the carb, is it shooting a nice stream when the trottle is opened.

I don't want to throw out too many questions, since it sounds like you are not stuck, as much as just letting us know about your progress.
Author:  Jeb [ Wed Jun 29, 2005 5:43 pm ]
Post subject: 
Where is this gizmo at on the air cleaner. It might be an OSAC valve, which is a big no no and is not to be used.
Author:  ceej [ Wed Jun 29, 2005 6:28 pm ]
Post subject: 
Yes, I checked it with the light. It was showing about 5 degrees base advance, and advances nicely when the butterfly cracks open. A wild guess would be around 20 degrees. I also verified it with a vacuum pump. The timing marks are a bit hard to read. The "Emissions" tag calls for TDC. Might be too advanced?

I'm going to pull it up into the shop Friday to find TDC. I still could have a problem with shifted timing marks on the balancer.

Rebuilt the carb a couple of years ago, but it sat for quite a bit of the winter, so will check the Accelerator pump. Was running a tad better on the way home from work. Labors a bit up around 50 to climb up to cruise, unless I mash it to the floor. Hmmm points toward not enough retard under acceleration, huh? Better break out the Kepner-Tragoe cards and see if I can save some time/energy.

It's got fresh gas. Ran it out two blocks from home earlier this month. :oops:
I'm getting ~17MPG right now. I'm hoping for a tad better. With my foot on the floorboard every time I merge into traffic it's not going to get very good economy.

Picked up a set of wires, some fresh plugs, and a set of front shoulder belts today while I was in town. Probably should have grabbed points and condenser too.

CJ
Author:  SlantSixDan [ Wed Jun 29, 2005 6:31 pm ]
Post subject: 
Quote:
Labors a bit up around 50 to climb up to cruise, unless I mash it to the floor. Hmmm points toward not enough retard under acceleration, huh?
No, "not enough retard" would be indicated by spark knock ("pinging"). Sounds more like not enough advance to me.
Author:  ceej [ Wed Jun 29, 2005 7:24 pm ]
Post subject: 
See? I should have stayed inside near the computer and listened to you!

Went out and took a couple of degrees out of it. Ran terrible. Took it up around 8 degrees, and it's much happier. Feels like I've got six cylinders again. Backed the idle off a bit. It was pulling a bit too much against the torque converter. Made the idle rough.
Smoothed out pretty well. Still has a bit of a miss, but the wires won't hurt. One of them bit my extension while I was playing with the front distributor bolt.

It's a bit too toasty under the hood to play with it much more tonight. Had to top up the expansion tank. Probably a hold over from the pump and timing set evolution.

We'll see how it does tomorrow morning. There's always the weekend. I'm on call through the long weekend, so won't be going anywhere.

I really need to get the two barrel on there if I'm going to continue driving it. That'll throw all the numbers out the window.

Thanks for the replies!

CJ
Author:  DusterIdiot [ Wed Jun 29, 2005 7:44 pm ]
Post subject:  Another thing to consider...
Just as an FYI,

My '74 duster with the Holley 1945 1 barrel had a #58 jet in it and it had a few flat spots (luckily it was a manual 3 spd...). That jet is a bit lean, the later years were jetted up to 61 or 63 (I jetted that one up to 61 and it smoothed things out a bit, gas mileage stayed the same, and then I bumped the timing to something much better...).


-D.Idiot
Author:  ceej [ Wed Jun 29, 2005 8:24 pm ]
Post subject: 
Probably ought to go ID my carb. I don't know what it is. When you get back someday, maybe I'll have the two barrel set up you got me on there.

How much longer you going to be gone DI?


CJ
Author:  ceej [ Wed Jun 29, 2005 9:03 pm ]
Post subject: 
Yup, 1945. I'll grab a kit. It's looking pretty scroungy anyway. I'll grab a #61 tomorrow. Shoot. I probably have a 63 rolling around in one of my tool boxes.
Can't find the last tool I set down, but I'll find a dirty little brass thing in a grimy tool box. Confidence. Yeah, positive vibes. I'll pick-up a #63 while I'm out. :roll:


CJ
Author:  DusterIdiot [ Thu Jun 30, 2005 1:37 am ]
Post subject:  Depends on how things look...
It depends on how the "standpoint" is over here... there's a lot of things I can't discuss, but that changes when I get home... :roll:

Anyhow...the events would be something like be home by mid-october for tax exemption, late October is when my contract is up, early November would be better as Ramadan is over and they stop trying to kill us for those bonus prizes in heaven(until the next holiday....) :shock:

so 120+/- days...

-D.Idiot
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