Backfiring, Stalling, Shaking..... all together.

F

Forddan

Senior Member
Hi

Let me explain my issues and see if anyone can help. I will do bullet points for each important event.

- on the clinic day I was told to change carburetor air filter and gasket (was a small leak)
- PV classic cars (ford A shop in Tewksbury) sold me a paper filter and gasket.
- And the problem started when I changed the air filter and gasket..
- car started to stall at some stops.
-tried to regulate island failed.
- carburetor started to leak pretty bad and car was shaking front to back.
- A local club member cleaned, assembled again the carburetor snd installed again in the car.
- The car didn't have the correct gas line. We had to use Teflon to stop a small leaking at the joint. It was in that way before.
-We left the car working inside the garage. All looked fine.
- Next day I took the car for a ride. It was terrible, shaking like crazy, like stalling and starting again.
- gas line was leaking and teflon tape gone.
-I bought the correct gas line. Installed and test drive the car.
-Car was smoother, but still shaking and started backfiring and "popping".
-drove to the mechanic.
-
At the mechanic shop they did:

A) took carburetor out and cleaned all again, just in case some of the teflon tape or something went in.
B)Replaced Cap, rotor, points and condenser (new style). The car has those installed.
C) installed new ignition switch and wire.
D) Cleaned spark plugs
E) car was timed many times.

-after all these, at the shop, the car sounded good.

-I took it for a ride it was smooth but was stalling each time I stop the car.
- Suddenly started to backfire so strong that neighbors called the police.
-The mechanics came to my rescue. I was afraid of driving it. Beside it was stalling, backfiring, shaking, all together. Terrible
- on the way back to the mechanic shop the car stoped and didn't start. NOW the car was losing spark.
-I was told that the points were not generating the spark. That issue allows gas to accumulate and produce the big backfire.
fortunately the mechanics were able to generate the spark. The car started and I make it to the shop.

For now, the car is still at the mechanic and they are trying to figure out why the lost of spark and why all these issues.

Any suggestion will be appreciated. Car do not have air filter now.

Thank you
Daniel
 
I would start by installing a new manifold gasket. Easy and does not cost much. On the carb connection to the manifold, make sure those two flanges are dead flat. They warp and let air into manifold. Hit them both with a file. Easy job. Go from there. Good luck.
 
I am not an expert, but if the carb is sorted out and now having electrical issues, check all your connects starting at the ground. Coil could be going bad as that would get worse as the car heated up.
 
If completely not firing to check for if a gas problem, try shootong some quick start or a misting bottle with gas into the air intake when cranking the starter - if it trys to run probably not a fuel issue.


If electrical.


Check/tighten/clean the battery connections.

Is your car running original design distributor parts/plates? Modern design parts, especially the wireless plate set ups are notorious for have strange and sometimes intermittent issues, including your issues.


Poor mechanical grounding of the distributor could be a problem


If original dist. parts, a misrouted shorting pigtail wire, or a broken pigtail wire.


All wiring/connections/crimps on the ignition wiring should be freshened in the ignition circuit. Make sure the ignition switch connections are tight/clean and not shorting to the gas tank, ammeter nuts are clean/tight, connections in the electrical box are clean/tight, etc., etc.


A thorough checking of connections is a good way to insure all is good.


If wanting to troubleshoot quickly I prefer using a multimeter/voltmeter, some prefer using a test lamp.
 
30 Closed Cab PU said:
If completely not firing to check for if a gas problem, try shootong some quick start or a misting bottle with gas into the air intake when cranking the starter - if it trys to run probably not a fuel issue.


If electrical.


Check/tighten/clean the battery connections.

Is your car running original design distributor parts/plates? Modern design parts, especially the wireless plate set ups are notorious for have strange and sometimes intermittent issues, including your issues.


Poor mechanical grounding of the distributor could be a problem


If original dist. parts, a misrouted shorting pigtail wire, or a broken pigtail wire.


All wiring/connections/crimps on the ignition wiring should be freshened in the ignition circuit. Make sure the ignition switch connections are tight/clean and not shorting to the gas tank, ammeter nuts are clean/tight, connections in the electrical box are clean/tight, etc., etc.


A thorough checking of connections is a good way to insure all is good.


If wanting to troubleshoot quickly I prefer using a multimeter/voltmeter, some prefer using a test lamp.
Click to expand...
exactly what CCPU Said, do a systematic approach. seems like its always the simplest of things. I would not use a paper element filter which can collect raw fuel or even vapour that is only inches from hot exhaust ,if you want or need a air filter just use the mesh screen type or no filter at all.
 
I think this point that you made is telling:


"-I was told that the points were not generating the spark. That issue allows gas to accumulate and produce the big backfire."





Do you have the "wireless" bottom plate in the distributor. You probably do as you mentioned that you have the modern points. Those wireless bottom plates are prone to trouble. How they work is that there is a springy brass bus and an acorn nut or a L shaped shoe that makes contact with the bus and brings power to the points. That springy brass can lose it's springiness, and then it will not make good contact with the acorn nut or shoe, causing intermittent loss of spark. When the contact reestablishes itself, the spark will return and it will light up all that unburned fuel in the muffler. I would change the wireless lower plate to the original style wire that runs directly from the lower plate to the points. Fewer moving parts to go wrong.
 
canadian said:
exactly what CCPU Said, do a systematic approach. seems like its always the simplest of things. I would not use a paper element filter which can collect raw fuel or even vapour that is only inches from hot exhaust ,if you want or need a air filter just use the mesh screen type or no filter at all.
Click to expand...
X2 I agree about the filter.


The High Boy with a K and N oiled element is an alternate option if you desire a filter.
 
Will N said:
I think this point that you made is telling:


"-I was told that the points were not generating the spark. That issue allows gas to accumulate and produce the big backfire."





Do you have the "wireless" bottom plate in the distributor. You probably do as you mentioned that you have the modern points. Those wireless bottom plates are prone to trouble. How they work is that there is a springy brass bus and an acorn nut or a L shaped shoe that makes contact with the bus and brings power to the points. That springy brass can lose it's springiness, and then it will not make good contact with the acorn nut or shoe, causing intermittent loss of spark. When the contact reestablishes itself, the spark will return and it will light up all that unburned fuel in the muffler. I would change the wireless lower plate to the original style wire that runs directly from the lower plate to the points. Fewer moving parts to go wrong.
Click to expand...
X2. I had the Nurex modern plates, ran into all kinds of odd issues. Upon advice went back to all original, upper and lower, and issues were resolved. Also added teh Brattons modified point block so newer points would align. Additionally what I noticed is from the plates moving from advancing and retarding the spark, there was wear on the bottom of upper plate and on the top edge of teh "shoe", and the wireless connection was not making really good connection electically.
 
BILL WILLIAMSON said:
It could be 179 problems! Keep it SIMPLE & diagnose it.
Bill W.
Click to expand...
X2 I agree Bill, I kind of alluded (but not clear) to that at the bottom of my post.


However from reading in between the lines, the OP may not have experience/knowledge of ignition trouble shooting. Was trying to give him some ideas/background. .
 
30 Closed Cab PU said:
X2 I agree Bill, I kind of alluded (but not clear) to that at the bottom of my post.


However from reading in between the lines, the OP may not have experience/knowledge of ignition trouble shooting. Was trying to give him some ideas/background. .
Click to expand...

Thank you all !!! You are correct, I do not have idea of troubleshooting. I will follow steps suggested on these postings and will report back. I am in the learning process and I hope, in some years, I can help others.

In the meantime thank you again for your guidance and keep fingers crossed.

Daniel
 
After some hours of testing and changing electric parts we found that the distributor LOWER PLATE, the section where the wire is attached was moving. The wire is attached to a metal piece. That piece is isolated from the plate. That piece had a little movement and that was making it grounding out. We replaced the lower plate, timed and car is running like a charm.

Now the funny part. After expending around $150 in replacement parts, most of them used on the car, so no regrets, the one that was really the issue (lower plate) was for free !!!

The Model A shop didn't have an old stile lower plate new. They gave me for free a used one that had the wire in perfect shape. Because it was used, it was free.

This free lower plate was a little bigger, almost nothing, but enough that we had to grind it a little to make it fit inside the distributor.

Before doing the grinding we tried the new lower plate that goes with the new points (has no wire). It was not working at all.

This is the end !!!

Thank you all for your suggestions that helped to find the issue and have you all a happy 4 of July.

I am going now to cut my hair driving the Model A .... HURRAY!!

Daniel
 
This what we changed. The section where the wire is attached had a little movement. Due to that is was grounding and the distributor did not have a spark at the points.

 
Very interesting. Usually a problem that develops right after you change a part, have something to do with what you just did. Just goes to show you most electrical problems are carburetor problems, and most carburetor problems are electrical. Smiley �� face
 
The plating in the "dimple" where teh ignition cable make contact looks a little iffy. May also have been causing intermittent problems?




Forddan said:
This what we changed. The section where the wire is attached had a little movement. Due to that is was grounding and the distributor did not have a spark at the points.

Click to expand...
 
Forddan said:
This what we changed. The section where the wire is attached had a little movement. Due to that is was grounding and the distributor did not have a spark at the points.

Click to expand...
Also, make sure that flag terminal that attaches to the points is bent at a 90 degree angle otherwise it can contact the spring and cause all sorts of weird intermittent problems. Ask me how I know :rolleyes:
 
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