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Offline Original74

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'79 Emissions and Vacuum Advance Question
« on: February 23, 2012, 12:17:13 PM »
Hello all,
 
I have searched the archives and don't readily find an answer to my question. My '79 daily driver is getting back on the road again after getting new gas tank straps made. It has a few issues I am tracing down, mostly a ping on light acceleration. I will get back to that.
 
In checking timing with my 40 year old timing light I timed my Pinto's with back in the day (such a blast!), I am supposed to be 20 with vacuum advance disconnected and plugged. I am at 18, not much off, but wanted to zero it in. So, looking down at the bolt to loosen the distributor, you can't see it due to a hose about 1 inch in diameter, running under the intake manifold, making a 90 degree turn up, then ending. In the end of this hose is a plastic piece with 2 vacuum barbs, one hose running to the base of the carb, a smaller hose running into the left fender well. Anyhow, this part is broken, has a spring and a plunger. My question is what is this part? With the part removed and the vacuum lines plugged, I am curious about that 1 inch hose that this thing plugged into is for. What is it? With the engine idling, there is no vacuum, nor air coming out of it. I taped it off, and as I said plugged the other 2 lines. The car runs a lot better, I think I had a vacuum leak with this part broken.
 
Another question, how to get rid of the ping on light throttle? Set it to say 14, going closer to TDC? I noticed I had no vacuum sucking from the vacuum advance line at idle. I recall from my '71 and '74, from back in the day, you had live vacuum on that line. I am sure with all the smog and emissions crap that is on this thing, things have changed.
 
Any ideas would be appreciated.
 
Dave
Dave Herbeck- Missing from us... He will always be with us

1974 Sedan, 'Geraldine', 45,000 miles, orange and white, show car.
1976 Runabout, project.
1979 Sedan, 'Jade', 429 miles, show car, really needs to be in a museum. I am building him one!
1979 Runabout, light blue, 39,000 miles, daily driver

Offline Original74

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Re: '79 Emissions and Vacuum Advance Question
« Reply #1 on: February 23, 2012, 08:56:08 PM »
Well, I figured it out, the part is the PCV valve. Never saw one that looked like that before, but the good thing is a couple bucks and you can have a new one!
Dave Herbeck- Missing from us... He will always be with us

1974 Sedan, 'Geraldine', 45,000 miles, orange and white, show car.
1976 Runabout, project.
1979 Sedan, 'Jade', 429 miles, show car, really needs to be in a museum. I am building him one!
1979 Runabout, light blue, 39,000 miles, daily driver

Offline dave1987

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Re: '79 Emissions and Vacuum Advance Question
« Reply #2 on: February 23, 2012, 09:11:55 PM »
The hoses that run to your fender are to/from the vacuum actuated valve on the charcoal canister. I didn't know either until I found a complete Pinto at the junk yard that had the canister on it. I robbed it of it's canister and valve and put it on my 78.
1978 Ford Pinto Sedan - Family owned since new

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Offline Original74

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Re: '79 Emissions and Vacuum Advance Question
« Reply #3 on: February 24, 2012, 10:31:54 AM »
Thanks for chiming in Dave.
 
I did some internet searching last night, after tracing the large tube that runs under the front of the intake manifold, back to a rectangular shaped metal box if you will, hugging off the left side of the block. This is I presume the 'breather' to let crankcase gasses out, with the PCV valve on the end of the large hose just above the distributor lockdown bolt.
 
I found this part available at several sources. The larger hose goes to a fitting at the base of the carb and the smaller hose goes into the left fender well. My guess is that the large hose is 'source' vacuum and the smaller hose is 'control' vacuum?
 
Your explanation of the 2 hoses going into the fender well are what I am seeking more clarification/understanding on. You mention the carbon canister. My '74 has a flexible tube connected to the side of the breather, running down into a frame mounted charcoal canister. I have only assumed over the years that gasoline vapors coming out of the top of the carb are routed to the charcoal canister to liquify and run back to the tank. Charcoal canister and crankcase gasses does not compute in my mind, LOL. Any additional explanation would be appreciated.
 
It amazes me, as I work on my car, that almost NONE of the issues I see today, with the car at 33 years old, were anything I experienced back in the day when they were new. But I love it! It sure is fun getting to use the timing light and tach/dwell meter I used in the '70's
 
Thanks,
Dave
Dave Herbeck- Missing from us... He will always be with us

1974 Sedan, 'Geraldine', 45,000 miles, orange and white, show car.
1976 Runabout, project.
1979 Sedan, 'Jade', 429 miles, show car, really needs to be in a museum. I am building him one!
1979 Runabout, light blue, 39,000 miles, daily driver