Insufficent Dwell

[lalkie]

I recently had a topic backfire and missing  and received a lot help.  that part has been basically fixed.  I now can't my dwell higher than 20 degrees.  I have pulled the distributor stetting the points a .025, had someone run the starter and moved the point adjusting screw without getting the dwell above 20 degrees.  the points and distributor are new, the distributor has about .002 run out when checked with a dial indicator.  The truck runs fine up to about 45 mph but is not quire right.  I am using the truck but would like help solving the problem.  Thanks Larry

[HanksB3B]

You redlined it ! 45 is about top end if you are running a 4.11 rear end (not according to Merle though..out here in L.A., we call him Ol'Leadfoot)

 

Hope you figure it out 

 

Hank 

Edited July 31, 2014 by HanksB3B

[Don Coatney]

Is your dwell meter set for a 6 cylinder engine? Can you try another dwell meter?

[desoto1939]

When you said new dizzy is this a NOS dizzy or a rebuilt dizzy or a used dizzy that you just purchased and put in the truck?

 

Check to verify the condition of the breaker plate assembly.  It might be worn and have some sloppyness.

 

i had a friend that had a 39 Desoto and was getting some porr performance. We took it to an old mechanic hed pulled the cap and was able to move the breaker plate. He told us to replace it. We pulled the BP and installed a NOS plate and reset the points which usuauly are set at 20 for the 39 Desoto. and then we had a good running engine and had power.  Are you correct at setting the gap at 25. Check your book for that setting seems to me that 20 is the correct number but I am not a truck guy. You can always set a little lower if your car/truck like that setting. Each car/truck has that specific smooth point that makes them happy and not always the factory setting is the perfect happy spot for them.

Even the timing mark is a starting point but adjust to where the truck runs smooth and has power.

 

This is just a thought.

 

Rich HArtung

[Dodgeb4ya]

Wider point gap = less dwell.

Point gap should be .020" I believe.

[Jeff Balazs]

I think the recommended gap range is .018" -.022". The best dwell reading I was ever able to get with my points was around 33 degrees at .018" gap.

 

Jeff

[lalkie]

The distributor is an original that appears to be good shape, the points are from napa and new,  I only have one dwell meter and it appears to be accurate on my other cars,  I will check the plate to see if that is a problem.  I will check the point setting.  I will have to check the gear ration in the rear end.  It has a 3-speed but I plan on putting a 4-speed in it later.  I think it came with a 4-speed.  Thanks for the response .  Larry 

[nonstop]

You might need to start looking at decreasing your gap for more dwell.

Also, only speaking from experience, is your dwell meter hooked up correctly for a positive ground? I have been caught by that many times!

[Robert Thornton]

Having trouble with timing , Replaced plugs cap rotor points set at 20 deg. timing mark lines up on #1 at 7 o'clock got it to run pretty good. the dizzy is fully retarded and timing mark is 6 to 8 in off to the right. Truck runs really good at all speeds. cranks good do I just leave it as is or try to find how to line it up. I have never had the dizzy out. Had truck 15 years with no trouble. Thanks for your help. I have read every timing thread on forum. just cant find this problem,   robert 
 

 

[Don Coatney]

Having trouble with timing , Replaced plugs cap rotor points set at 20 deg. timing mark lines up on #1 at 7 o'clock got it to run pretty good. the dizzy is fully retarded and timing mark is 6 to 8 in off to the right. Truck runs really good at all speeds. cranks good do I just leave it as is or try to find how to line it up. I have never had the dizzy out. Had truck 15 years with no trouble. Thanks for your help. I have read every timing thread on forum. just cant find this problem,   robert 

 

Pull the distributor. You will find a second adjustment bolt that will allow you to dial in the timing with precision.

 

 

[Robert Thornton]

Thanks Don you're right I cant loosen backside bolt with out removing dizzy. I have never pulled one how do you mark it to get back in place. do you put #1 in t d c and line up timing mark . with rotor  pointing at #1 at 7 o'clock . then mark it some where.  Thanks Robert

[desoto1939]

You can basically take the dizzy out of the engine block in any position sinc e the end of the shaft is a slot in a keyway inthe oil pump.

 

I mark the engine block in comparision to a specific point onthe dizzy body then also make a mark onthe dizzy body to refernece where the current position of the rotor.  Remember and I state again  DO NOT, Again DO NOT hit your starter motor this will then chnage your refernece points.

 

MAke the necessary chnages to the points or  minor adjustment bracket.  Then sect the reference points back up and then reinstall the entire unit. MAke sure that the slot onthe end of the dizzy goes into the key way in the oil pump. Tigh up the dizzy but not all the way. Hookup your timeing light start the engine and then fine adjust via the timing mark.  The first time is the hardest if you have never done this but after you have done it you willbe proud of yourself.

 

Rich Hartung

Desoto1939@aol.com

[HanksB3B]

My truck's been faltering at full throttle (gas starved or timing) so I'm about to file and set my points for the umpeenteth time since I've owned my truck.   I'm going to set them at .018 per Jeff's post (above).  I will remove the distributor, do the work and then re-install it. I'm comfortable with that and it is the best way. Short of having a country road and a fifteen year old buddy to ride the fender and tweak the distributor to the ideal point,   I think I'll ask my neighbor Kent to help me out with his timing light.

 

Hank 

 

 

P.S. I have considered converting to Pertronix but not right now there's other things I want to do first. It'll surprise you all but that's another thread.