Zero vacuum at idle

[48ply1stcar]

I installed my rebuilt engine last spring.  I haven’t been able to get able to get it to run well at all.  Recently I have timed the engine with and vacuum gauge, because I get a better result than using a timing mark.  I have zero vacuum at idle and 15psi at 1100rpm.  The is a video on a timing thread posted here showing "finding the sweet spot" I discovered that I needed to loosen the lock plate from the distributor to move it far enough. 

 

Researching here has made me question everything. Everything from a distributor ground wire, plug wires, rebuilding the carb.

 

When I do have vacuum the gauge is always steady indicating air leaks or timing. (rebuilt engine, so not low compression)

 

Question, could air leaks in carburetor gaskets cause zero vacuum at idle, or should I concentrate on timing.  Also, it seems to me that a vacuum wiper in the off position is a built-in vacuum leak.

[Don Coatney]

How is your vacuum gauge connected? Sounds as if it is connected to the vacuum advance port at the base of the carburetor. Should be connected to the intake manifold.

[Silverdome]

Yes what Don Said. If you're worried about the wiper motor then disconnect it and plug in the gauge there and check the reading. Then put a tee in at that same port and reconnect the wiper motor that will eliminate whether the wiper motor is the source of low vacuum.

[Merle Coggins]

I was going to suggest the same question as Don stated above. It sounds like you are on ported vacuum, not manifold vacuum. Also, for future reference, vacuum is measured in Inches of Mercury, or inHg, not PSI. It would actually be a negative number if reading PSI.

[48ply1stcar]

Merle, I knew that just didn't write it right or correctly.  Now I have to find or make a vacuum port on my intake manifold????????  This my sound crazy, but I never used a vacuum gauge on my car before and not aware of what, where, or how to attach a vacuum gauge to the manifold.  I check my engine pictures and found a plug on top of the manifold.  Should there there be a big sign that says start here dummy?

[knuckleharley]

2 hours ago, 48ply1stcar said:

I installed my rebuilt engine last spring.  I haven’t been able to get able to get it to run well at all.  Recently I have timed the engine with and vacuum gauge, because I get a better result than using a timing mark.

Ok,you have me confused there.  The timing mark and distributor are connected at the hip. If you are timing the engine and ignoring the timing mark,the distributor has been installed without it pointing at number 1 cylinder. I have an engine that was timed 180 degrees off when I got it,but  the plug wires were installed 180 degrees off in the distributor cap to compensate. I know it is off 180 degrees,so no big deal.

 

Given the problems you are having with this while trying to learn about how your car operates,you really need to get your firing order set on the number 1 cylinder and then install your distributor so the rotor cap points at the number one plug wire position. That will make any further research or work you do on this a LOT less confusing to you.

 

Buy a motors manual from ebay,Abes Books,etc,etc,etc,that covers the year 1948,and go to the tune up and ignition sections and read them VERY carefully. In fact,read them while looking at your engine and ignition system,and reread them until it all makes sense to you. The basics are the basics for good reasons. Everything begins there.

 

The tune up section will even tell you how to use your vacuum gauges and what the different readings indicate.

 

Buying a Motors Repair Manual that covers 1948 will be the best money you will ever spend on your car.

Edited May 2, 2018 by knuckleharley

[48ply1stcar]

3 hours ago, Don Coatney said:

How is your vacuum gauge connected? Sounds as if it is connected to the vacuum advance port at the base of the carburetor. Should be connected to the intake manifold.

Don is the intake vacuum connection made at plug on the rear-top of the manifold as shown in the picture above.  I'm trying to fine an example on the site.

 

[greg g]

Yes that plug is a manifold vacuum port. Unscrejw the plug,take it and the vacuum gauge to the hardware and have one of the helpful hardware guys hook you up with some brass fittings to make the connection. When done, reinsert!t the plug and keep the fittings with the gauge.  If I remember there was a small yes right here dummy sticker on my stock intake....

[48ply1stcar]

Thanks Greg, I'll get a couple of the those "Right here dummy" stickers while I'm at the hardware store.  

[48ply1stcar]

On 5/2/2018 at 11:38 AM, knuckleharley said:

Ok,you have me confused there.  The timing mark and distributor are connected at the hip. If you are timing the engine and ignoring the timing mark,the distributor has been installed without it pointing at number 1 cylinder. I have an engine that was timed 180 degrees off when I got it,but  the plug wires were installed 180 degrees off in the distributor cap to compensate. I know it is off 180 degrees,so no big deal.

 

Given the problems you are having with this while trying to learn about how your car operates,you really need to get your firing order set on the number 1 cylinder and then install your distributor so the rotor cap points at the number one plug wire position. That will make any further research or work you do on this a LOT less confusing to you.

 

Buy a motors manual from ebay,Abes Books,etc,etc,etc,that covers the year 1948,and go to the tune up and ignition sections and read them VERY carefully. In fact,read them while looking at your engine and ignition system,and reread them until it all makes sense to you. The basics are the basics for good reasons. Everything begins there.

 

The tune up section will even tell you how to use your vacuum gauges and what the different readings indicate.

 

Buying a Motors Repair Manual that covers 1948 will be the best money you will ever spend on your car.

Dear Mr. Knuckle

I had temporary lost my mind and my confidence in the timing marks.  You see I had the harmonic balancer restored and I cut in the marks so I questioned my ability.  Also it is a rebuilt 56 230 so I again question if It should be 2 BTDC or a little more. 

I think the timing is close and using the vacuum gauge with right hole. I get 18 inches of vacuum and it vibrates rapidly between 17.5 to 18.5.  Also the vacuum wipers work that only install this year, 50 years after I put in the second engine.

In addition the carb is flooding, so I might as well rebuild the carb.   Getting fuel at the base of the carb after a short trip and flooding.

 

Back in 90s, I drove to work and have fewer problems with the old 218, of course with its compression I could rope-start that engine.  

Just started to get the car ready after 6 months of Winter.

Edited May 5, 2018 by 48ply1stcar

[knuckleharley]

44 minutes ago, 48ply1stcar said:

Dear Mr. Knuckle

I had temporary lost my mind and my confidence in the timing marks.  You see I had the harmonic balancer restored and I cut in the marks so I questioned my ability.  Also it is a rebuilt 56 230 so I again question if It should be 2 BTDC or a little more. 

I think the timing is close and using the vacuum gauge with right hole. I get 18 inches of vacuum and it vibrates rapidly between 17.5 to 18.5.  Also the vacuum wipers work that only install this year, 50 years after I put in the second engine.

In addition the carb is flooding, so I might as well rebuild the carb.   Getting fuel at the base of the carb after a short trip and flooding.

 

Back in 90s, I drove to work and have fewer problems with the old 218, of course with its compression I could rope-start that engine.  

Just started to get the car ready after 6 months of Winter.

There is a possibility the timing marks are no longer good after the rebuild. I have heard of this happening. No real big deal if you know what the problem is. Just get your engine on TDC on number 1 clinder,and rock it back and forth with a breaker bar (MUCH easier to do if the plugs are out) until the points fire. Mark that on your balancer and disregard any other marks.

 

I feel yore pain on the carb. Am having that problem with my 51 Ford Victoria right now. Not only did it sit for over 10 years before I bought it,but the carb on it was the wrong carb and didn't have a dash pot. Which meant it wanted to quit running when I stopped or tried to start. The last time I drove it the carb was leaking gas so badly I stopped and bought a fire extinguisher to ride home with me.I could literally smell the leaking gas while riding down the road.  It is still parked where I cut it off when I got home.

 

Nobody seemed to know what the original carb parts number was,and I was told by all the carb builders and kit suppliers that "everybody" uses that the dash pot and the bracket were impossible to find.

 

So I went searching the internet for a 1951 Carb. Not one single hit. LOTS of false promises from people who advertise "we have everything you need!",but don't.

 

Then I thought about it and figured that there were a LOT more 52's and 53's sold with auto transmissions,and they used the same engine. So I did a ebay search for 52 Ford on ebay automotive parts. Found a junkyard selling a 52 FOM transmission "that was pulled from the car as is,and the condition is unknown".  "Hmmmm! This is a auto junkyard. If they have the transmission and say they pulled it from the car,maybe they still have and are parting out the engine?",I said,so I did a store search to see.

 

Sure enough,that carb was the very last item they had listed out of 139 items,and the price was $54 bucks,delivered! I got it in yesterday,and the screw heads are pristine,and it looks like it has never been touched. The choke plate is stuck,the float was stuck until I shook it,and the dash pot is also stuck. No big deal. I knew the dash pot would be junk anyhow after all these years,so I had already ordered a new dash pot from ebay for $24.95.  I could do that with confidence because after seeing the ebay page,I knew what it looked like. Come to find out the dash pot bracket is the part that is hard to find.

 

Then I got the carb in yesterday,cleaned it up enough to discover all the numbers on it,and found out that same bracket and dash pot was used on Ford products with the Y-Block engine all the way up to around 1964.

 

For any of you who want to whine about this being non-Mopar,carburetors and other mechanical parts for obsolete cars are just as hard to track down as non-Mopar parts,and the same methods will apply.

 

Yeah,it has been a pain in the butt,but  if I have to rebuild a carb to put on an original car,I want it to be the RIGHT carb. Getting the right carb  that appears to be unmolested and missing no parts is a bonus. Sometimes you just have to dig and ask. Seems to me a lot of times the missing part I am looking for is such a minor part that nobody bothers to list them,so you have to look for related parts,and then send the seller a email asking them if they also have the part you want. You might be surprised at the luck I have had doing that.

Edited May 5, 2018 by knuckleharley