Misfiring because of worn timing chain?

[Kai-by-Vecona]

Hi Everybody,

 

I have a misfiring problem on my D22.

 

When the engine is on higher rpms i have a misfire so the car wouldn't go faster than 45 to 50 miles. It also has not full power on full accelaration.

 

First I thought it was the braker, so I installed a new on, including finger, distributor cap, wires and spark plugs, but it didn't solve the problem. Then I tried an electronic ignition but it won't be better. Then I thought it may be a fuel problem and rebuilt the carburator but nothing happened. By the time I installed a new carburator, new fuel pump, new rebulilt distributor, new fuel filter and checked vaccum and all that stuff. Now I run out of ideas. When I check timing it seems to be everything ok but the marks jump a little bit.

 

Then I remenbered a post, that I didn't find anymore saying it may be a problem of a worn timing chain that could affect the timing in higher rpms.

I'm not sure if this could affect the misfiring in higher rpms. Did anyone heard about that or have another idea?

 

Thanks a lot

 

Kai

[RobertKB]

I doubt it is the timing chain. One thing you could check is the rubber hose that runs from the steel gas line to the fuel pump. It is about 6-8 inches long. It may look OK but it can become quite weak. When the car is pulling hard and revving high it will sometimes cause this hose to collapse a bit causing the problems you have described. I had this problem on my '53 Plymouth and replacing the hose corrected it. Andy Bernbaum or Roberts probably sell this hose. An alternative is you can add a couple of fittings and just use a regular modern gas line hose with clamps.

Edited December 28, 2014 by RobertKB

[Jeff Balazs]

What do you mean when you say the timing mark jumps a bit? Can you describe what you see when checking the timing?

It sort of sounds like you may have a misfire. Plugs?....wires?

 

Jeff

[John Reddie]

I agree with the post by Robert KB. You appear to have replaced the same things I would do in your situation. Two thoughts. How clean is your air filter? A partially clogged air filter can produce symptoms that you describe as the engine is starving for air especially at high speed. Also I would check for an exhaust restriction for instance, a stuck closed heat riser valve or a plugged up muffler. This will cause excessive back pressure.

Good luck to you.

John R

[Dave72dt]

Your problem could still be in the ignition system.  I assume it has a vacuum advance system built into the dist.  If so, that needs to be functioning correctly for both power and consistent fire at higher rpm.   Check the dist shaft for side movement, and the point spring for proper tension.  Either of those can cause the points to bounce at higher rpm and cause misfires.

[greg g]

Have you done a compression test?  A worn chain will change timing a bit causing a general lack of power, lazy acceleration, mut not a miss fire.  Do the points have sufficient spring pressure, is your condenser good, is your vacuum advance working properly, is there a leak in the vacuum line between the carb and distributor?  Have you done a vacuum gauge reading at idle?  And finally is your exhaust system flowing freely?

Edited December 28, 2014 by greg g

[Kai-by-Vecona]

Hello Everybody,

 

thanks for all that info. Here are some answers:

 

@RobertKB. I didn't check the hose but I have a clear fuel filter and I thought I might see it if the fuel lever get's lower.

@Jeff Balazs. Plugs and wires are new. I mean that the mark on the damper jumps 5° up and down with idling in the same speed.

@John Reddie. I run the car with the original oil bath cleaner. The result is the same with or without air cleaner. I checked the heat riser valve and it seems to work properly. The exhaust system is brand new. That shouldn't influence it.

@Dave72dt. Yes it has a vaccum advance system. I checked the function of it with a vaccuum pump and it worked. The ignition does not have points any more.

@greg g. I made a compression test. It has a minimum of 80psi on 5 and 6 and 90 on first cylinder. It also has a lazy accelaration. As I told there no points or condensor left in the distributor. I have a vaccum gauge and made a test but maybe I shouldn't have bought the cheapest tool because I wasn't able to get to the results of teh shop manual but it was enough to see that it works. I didn't find a way to see properly if the spring in the vaccuum advance need more or less tension. But I have two vacuum advanced units and it's the same result with both.

[Jeff Balazs]

Well it should not be doing that. Have you checked the pulley to see that it is tight on the crank? You mentioned that the distributor was rebuilt. I wonder if there is excess play in it? With the distributor cap off try having someone turn it over and look for a wobble in the shaft. Also you might want to inspect the cap and rotor for damage or any sign of a poor fit.

 

I am probably in the minority here but I think it is possible for severe wear on one of these chains to cause a problem like this. But you should rule out every other possibility before you go after that one. It is a relatively easy job when the engine is out of the car but it may be a bit of a stinker with it in place.

 

Hope this helps, Jeff

[Kai-by-Vecona]

Hello Jeff,

 

that's what I would try to find out if it could be caused by something else. I go to have a look if the distributor shaft has a play, but I never heard to change the bearing or get the parts for it.

I would do the timing chain job if I don't get any other ideas.

Thanks

 

Kai

[DutchEdwin]

Hello Kai,

The distributor has two functions that will advance the ignition.

1) the vacuum advance,

2) the centrifugal advance, higher rpm, higher advance.

This centrifugal advance is nothing else then two weights that are spring loaded. At my '55 it is located under the plate where the contact points are mounted on, I think it's the same at your '42. It is lubricated with oil. Mine was not moving easy because of old oil and dirt. By cleaning this it was operating fine again. Did you check this?

Edwin.

[Don Coatney]

If you have no points what ignition system do you have?

[RobertKB]

I still think it could be the hose I mentioned earlier. Also, is your tank clean? If the filter (usually a meshed covered permanent filter at the end of the pick-up) in the tank is plugged with old gas and other crud, you could have lack of fuel under acceleration. A tank could be gummed up and not put a lot of dirt through so your filter will look OK. Why not disconnect the rubber hose from the fuel pump, put a fitting in the place where the hose goes, and attach a new piece of gas line hose and run it off a gas can placed wherever it will fit. Take it for a drive and see if it makes a difference. If you still have the problem you can at least rule out the small rubber hose and the gas tank as suspects.

[BigDaddyO]

Who has no points?

[Don Coatney]

BigDaddyO, on 28 Dec 2014 - 10:56 PM, said:

Who has no points?

Hello Everybody,

 

thanks for all that info. Here are some answers:

 

@RobertKB. I didn't check the hose but I have a clear fuel filter and I thought I might see it if the fuel lever get's lower.

@Jeff Balazs. Plugs and wires are new. I mean that the mark on the damper jumps 5° up and down with idling in the same speed.

@John Reddie. I run the car with the original oil bath cleaner. The result is the same with or without air cleaner. I checked the heat riser valve and it seems to work properly. The exhaust system is brand new. That shouldn't influence it.

@Dave72dt. Yes it has a vaccum advance system. I checked the function of it with a vaccuum pump and it worked. The ignition does not have points any more.

@greg g. I made a compression test. It has a minimum of 80psi on 5 and 6 and 90 on first cylinder. It also has a lazy accelaration. As I told there no points or condensor left in the distributor. I have a vaccum gauge and made a test but maybe I shouldn't have bought the cheapest tool because I wasn't able to get to the results of teh shop manual but it was enough to see that it works. I didn't find a way to see properly if the spring in the vaccuum advance need more or less tension. But I have two vacuum advanced units and it's the same result with both.

[Kai-by-Vecona]

@DutchEdwin. Yes .. I cleaned everything and the centrifugal weights seemed to do fine.

@Don. I installed a electronic ignition from classicheads.com including a new ignition coil. It's just a small part mounted on the braker plate of the original distributor.

@RobertKB. That would be an idea. I thought fuel should be ok because the level in the filter was ok but who knows...

[Jeff Balazs]

I am not familiar with that suppliers pointless kit. Do you have any paperwork for it? Did the timing marks read the same way before you replaced the points? Some kits have a module that extends the duration of the spark......

 

Jeff

[Don Coatney]

Has this engine ever ran correctly with full power after you installed the pointless ignition system?

[BigDaddyO]

Hello Everybody,

 

thanks for all that info. Here are some answers:

 

@RobertKB. I didn't check the hose but I have a clear fuel filter and I thought I might see it if the fuel lever get's lower.

@Jeff Balazs. Plugs and wires are new. I mean that the mark on the damper jumps 5° up and down with idling in the same speed.

@John Reddie. I run the car with the original oil bath cleaner. The result is the same with or without air cleaner. I checked the heat riser valve and it seems to work properly. The exhaust system is brand new. That shouldn't influence it.

@Dave72dt. Yes it has a vaccum advance system. I checked the function of it with a vaccuum pump and it worked. The ignition does not have points any more.

@greg g. I made a compression test. It has a minimum of 80psi on 5 and 6 and 90 on first cylinder. It also has a lazy accelaration. As I told there no points or condensor left in the distributor. I have a vaccum gauge and made a test but maybe I shouldn't have bought the cheapest tool because I wasn't able to get to the results of teh shop manual but it was enough to see that it works. I didn't find a way to see properly if the spring in the vaccuum advance need more or less tension. But I have two vacuum advanced units and it's the same result with both.

Boy, it's hard to miss when it's in red.

[Kai-by-Vecona]

I'm in holyday so I don't have the paperwork with me :-(.

The engine runs better with the pointless ignition but it just shifts the misfiring from 30-40 to 40-50 miles. That's why I thought it might be something else. One idea is, that the main metering jet in the carburator is too small. But I installed the original rebuilding kit so it might be right. Maybe it has something to do, that it's a 1950 engine with the original carburator and ignition. Think the swapped the engine sometimes and installed the original stuff. As far es I know it shouldn't make any differences but who knows.

[Don Coatney]

When did this misfiring problem first occur? What work was done prior to this misfiring issue?

[Kai-by-Vecona]

The car was kept in a garage since 1993 and was driven not very often and just short distances. When I get the car from the states in 2012 it did the misfiring. I thought it just could be some small stuff like timing or breakers but it didn't. I did the following jobs on the engine:

 

 

First I thought it was the braker, so I installed a new on, including finger, distributor cap, wires and spark plugs, but it didn't solve the problem. Then I tried an electronic ignition but it won't be better. Then I thought it may be a fuel problem and rebuilt the carburator but nothing happened. By the time I installed a new carburator, new fuel pump, new rebulilt distributor, new fuel filter and checked vaccum and all that stuff. Exhaust is also new. Now I run out of ideas. When I check timing it seems to be everything ok but the marks jump a little bit.

[Don Coatney]

Is your car running on 6 or 12 volts?

[Kai-by-Vecona]

6 Volt

[Don Coatney]

Have you ever replaced the ignition coil?

[_shel_ny]

...

Edited December 29, 2014 by shel_ny