backfiring and not much power

[A nubie]

Ok guys, got my brakes adjusted and was finally able to get out of the driveway with my new toy. It doesn't have a temp gauge but it seems to be getting hot very quickly. Maybe my imagination. it doesn't have any power and backfires a lot. The hotter it got the worse it got. Any advise.

[Mike V. Florida]

Where is the spark lever set?

[Kirby1374]

check to see if your timing is not too retarded and that you carb adjustments are right. Idle mix and the gas valve that is also the choke rod. Also, you probably know this but you should pull the spark advance lever about half way down (more or less) after start up.

[Kirby1374]

oops Mike types faster.....

[Patrick L.]

Like said, the the left hand lever is the spark lever. It should full up for start and about 1/2 way down [ 9:00] once running. That is, if the ignition timing is set correctly. You may want to open the GAV [choke rod] a turn counter clockwise for starting and close to about 1/2 turn out as the engine warms for most running until you find out what works best. Try leaving the gas cap loose and see if that helps also. Try these and let us know what happens.

[Richard Wilson]

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Could be trash/rust in the gas tank clogging the fuel line causing the carb to lean out. Take gas line loose at the carb and see if you have good flow to carb. Only takes about 4-5 minutes to check.

[A nubie]

Ok as I am new to model A's the guy i bought it from told me to start with the spark lever all the way down. Hope that will not damage anything but i will start with spark lever up from now on. While on the drive i did try to move spark lever up but power decreased. about 8:00 was as good as it got. I have always dealt with diesel engines and do not know much about timing. is there Anyone you could recommend to look at this in the San Antonio area.

[ctlikon0712]

Sounds like you need to start with the basics first. Get/buy one of the copy owners manuals for your Model A (about $10) and use the search function at the top of this page. There is a wealth of infor that has been discused on here. It sounds like you should go through your timing and fuel before driving anymore.

Timing how to http://video.search.yahoo.com/search...nr=20&y=Search

good all around book http://www.amazon.com/Model-A-Ford-m.../dp/0965824004

owners manual http://www.ebay.com/sch/i.html?_odkw...anual&_sacat=0

[christian]

like the guys before said, spark rod: all the way up is full retard, all the way down is full advance.

for starting, bring rod all the way up for full retard, once running bring the rod down some to get a smooth idle. usually about half way down. when cruising bring about 3/4 down or so. good luck. I second the idea of getting the original model a owners manual. there is a lot of info in there, pretty much everything you need to know on how to drive it. (probably why it was included with purchase of the car)

[A nubie]

Thank you all for your help. I will invest in owners manual. I really appreciate all of your time.

[Mike V. Florida]

Until you buy your own here is on on line.

http://www.motormayhem.net/mode-a-fo...owners-manual/

[newshirt]

And how do you know if your timing is set correctly?

https://www.youtube.com/watch?v=qudpRXZE3Yo

[ctlikon0712]

Did you watch all the videos? There is more than one.
The check is the pin in the gear and then the light indicating the points/cam relationship in the proper time for cyl. #1.

[Mad Mac]

After driving my Model A for more than 20 years I discover from this thread that I have been using the spark lever incorrectly all these years!! I start with it fully retarded (up) and then gradually advance it all the way down for highway driving. In one of the above threads someone says it should be about three quarters down for normal driving, so have I harmed my engine (eg loaded up the bearings) by driving fully advanced?

Also in post#9 Christian says it idles smoother about half way down but I am sure mine idles much smoother and slower when it is fully retarded.

[700rpm]

Originally Posted by Mad Mac

After driving my Model A for more than 20 years I discover from this thread that I have been using the spark lever incorrectly all these years!! I start with it fully retarded (up) and then gradually advance it all the way down for highway driving. In one of the above threads someone says it should be about three quarters down for normal driving, so have I harmed my engine (eg loaded up the bearings) by driving fully advanced?

Also in post#9 Christian says it idles smoother about half way down but I am sure mine idles much smoother and slower when it is fully retarded.

You might have harmed the bearings by driving with it fully advanced; it depends on how you were driving it (highway, parades, up hill, etc.).

It will idle much more slowly in the retarded position. Smooth running depends on a lot of other factors, like fuel mixture, timing, points, and such.

[ctlikon0712]

This is what Henry told the new purchaser of the Model A's about driving and timing advance....

[jmeckel]

Originally Posted by 700rpm

You might have harmed the bearings by driving with it fully advanced; it depends on how you were driving it (highway, parades, up hill, etc.).

It will idle much more slowly in the retarded position. Smooth running depends on a lot of other factors, like fuel mixture, timing, points, and such.

Were you run the spark advance has a lot to do with how the timing is set. If it is set exactly by the book, then you can follow the book for setting the spark advance as you drive as a guideline. You should be able to hear how the engine is running and set the advance for best operation, based on load and rpm's of motor. Once you understand what a good running sounds like your ear will tell you what position the advance should be in. Your GAV setting will also be part of the formula of a good running engine.

[Jim Parker Toronto]

If all of the above suggestions don't seem to help your no power and backfiring problem, you may want to check your head gasket..... a compression test will help to show this

[Tom Wesenberg]

From the information in the first post, it sure sounds like late timing. Set the timing by the book, and pull the lever down half way as soon as the engine starts. I then pull mine about 3/4 down while driving 30 to 45 MPH.

If you have a high compression head, they take less advance.

[robw]

Backfiring and lack of power could also indicate a lean condition... which could result from carburation issues, or a vacuum leak around the intake...

start with fuel flow... if you have good fuel flow, check to see if it runs better with some choke... close the choke a bit and see if the backfiring stops. If the partially closed choke makes the backfiring stop, you are running lean...

If you are running lean, take a can of WD 40, or carb cleaner and being sure to use the straw that comes with it, run the engine and spray around where the intake manifold meets the head... spray from a variety of angles. Spray with small shots... if you suddenly hear a change in rpms you've found your vacuum leak. Also check where the carb mounts to the intake manifold using the same method. If you have the vacuum port for windshield wipers... check that too.

If you don't find any vacuum leaks you may have a plugged metering jet in your carb, or your float level may be too low.


Rob

[Ca. Kid]

Also make sure your battery is hooked up pos ground. It will run neg ground, just not very well.

[Mitch//pa]

you need to go over this car properly,start with the basics and reset/ clean and or replace the points/condenser and reset the timing to proper specs. possibly also go through the carb by cleaning it out or getting one from berts which are reasonable "the guys have had good reports of them".

[Gino]

Morning people, my story goes like this. After having to flat bed my Coupe back to my garage, maybe a half doz. Times, and I was close to scrapping her, I called this old guy wok has worked on A's for 70 + years. After many trials and tests, we found a small piece of metal under the upper plate in the distributor lol. Problem solved no more back firing or loss of power.

[Mitch//pa]

Originally Posted by Gino

Morning people, my story goes like this. After having to flat bed my Coupe back to my garage, maybe a half doz. Times, and I was close to scrapping her, I called this old guy wok has worked on A's for 70 + years. After many trials and tests, we found a small piece of metal under the upper plate in the distributor lol. Problem solved no more back firing or loss of power.

would that small piece of metal be part of a modern lower plate with the brass contact??? they cause that exact problem

[Phil]

We say it all the time here don't think any one said in this post. Find and join your local model A club. There is a good one in your area, they will be eager to help you. They have a wealth of knowledge.

[Allanw]

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Since we're talking about spark advance etc...

DOes anyone know what the octane rating of the gaslone would have been in the 20's/30's???I've read 60-80, but have nothing solid.

I'm expecting it was a lot lower than it is now (Many old cars specify FAR lower required ratings than any modern fuel has, I've seen 50's cars that required 72 octane and similar), so if you still have stock compression, the lever can probably be pulled further down without problems, couldn't it? It would be far less prone to pre-ignition.

Once cruising on any flat road (45 MPH or so) I run it between full advance and a couple of clicks up. I move it closer to half on steep or long hills.

I know I don't want to run it too retarded either, because the exhaust gas temperature skyrockets and you start risking over heating, or cracked heads and saggy exhaust manifolds.

I wonder if Henry's advice in the book still applies less with more modern fuels and higher octane ratings?

[roccaas]

Check joint between carb and manifold, and if you have an air leak in carb.


I had a bad gasket and a warped Tilly top half. Very lean, no power, lots of GAV.

Lean test is to gently downshift while coasting downhill. Popping=LEAN.

[MikeK]

Originally Posted by ctlikon0712

This is what Henry told the new purchaser of the Model A's about driving and timing advance....

Interesting thought here- Back when A's were new gas was 60 octane on a good day, and you could probably easily get audible spark knock with too much advance, even with the 4.22CR. That must have made it easy to learn how to play the advance lever.

With today's worst gas at 87 octane full advance at 4.22CR may not produce any spark knock, but will certainly present too much cylinder load while still on the upstroke. Not readily detectable by ear, you now need a very good 'feel' for how the engine behaves. Not everyone has that fine touch.

The learning curve is steeper today than back when.

[roccaas]

Originally Posted by MikeK

Interesting thought here- Back when A's were new gas was 60 octane on a good day, and you could probably easily get audible spark knock with too much advance, even with the 4.22CR. That must have made it easy to learn how to play the advance lever.

With today's worst gas at 87 octane full advance at 4.22CR may not produce any spark knock, but will certainly present too much cylinder load while still on the upstroke. Not readily detectable by ear, you now need a very good 'feel' for how the engine behaves. Not everyone has that fine touch.

The learning curve is steeper today than back when.

I never though of this!! Could this be the reason I blew the #3 big end at 45 mph a few years back with the advance all the way down?

Recently, I've found the car runs better on the street at 8:30 to 9:00 rather than 7:30.

[Patrick L.]

Yep, what Mike just said. It takes a little practice and some feel. But, playing with the spark lever will produce a noticeable difference in what the engine likes and dislikes without ever hearing detonation/spark knock.

[RonC]

Your best advice is to find someone in the San Antonio area that can look at your car for you. I'm sure there is a local Model A club that you could attend a meeting. Your condition could be caused by a variety of maybe or not so maybe obvious causes. Not knowing the history of your car you should at least start with a compression test of the engine, check fuel flow and the ignition system.