What problems could a loose condensor cause

Started by junkyardjeff, June 29, 2008, 12:42:35 PM

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junkyardjeff

I had to remove the electronic distributor since the advance curve was wrong for a presmog motor and put the points distributor back in,went for a 150 mile round trip and thought I would not make it home.  I checked the points and they were burnt and had not been in very long so I got another set and noticed the condensor was loose,will a loose condensor cause the points to burn or if it does it again look somewhere else for the problem.  Jeff

wayne petty

electrons have mass... when they get going if you break the contact they will try to jump the gap...  

it is a tuned circuit.. if the condenser is too small the points will burn with the buildup on one contact face... if too large the buildup will be on the other side.

if the condenser is loose.. it may barely run... or backfire... as part of the tuned circuit is not there...

if you have ever seen a scope display of the secondary ignition...

there will be a voltage spike when the points open and the buildup of voltage increases till it can flash over the resistance and gaps in the secondary..

the voltage drops at a steep angle then levels off as the arc stabilizes and the electrons flow from the coil...    the angle of this "step" shows how the wires and gap between the cap and rotor are...    it should be nice and crisp... level...  

then there should be at least 5 cycles of the coil as the winding have emptyed and the residual voltage goes below and above 0 till it levels out...

it should stabilize until the points close... then drop down and get 5 more cycles above and blow as the primary charges.. this secondary is the condenser ability to absorb and dampen the electron flow...

at least that is how it was explained to me... by 2 members of the 200 mph club who were teaching autoshop here in los angeles...  in the late 70's

wayne petty

keeping this tip separate...

clean the point contacts with rubbing alcohol or brake cleaner,  the manufacturers have coated most of the sets with clear paint to stop the rusting and corrosion problems that will reduce sales from sitting on a shelf for years...

do lube the rubbing block and the point cam with high pressure grease...

bosch had a good one.. in a squeeze tube that would take years to use up one dab at a time...

last time i called the vw parts wholesaler... i ask about it... he did not think they had it any more..  i gave him the number off the empty tube i used to have... they had 80 tubes... but i forgot to order some.. and that shop is now closed... thank god...

oh... back to points cleaning.. if they are covered in grease or a coating. they will burn as the material turns to carbon do to the heat of the arcing..

if they contact at all...  sometimes they get coated and do not conduct current.. which makes for some tail chasing...  not that kind...

and please what ever you do...     don't ever use silicone spray .... you won't like it...  the silicone tends to migrate onto the contact faces... leaving you wondering what the problem is.. as the points are opening and closing...

oh... and if you position the motor .. with the points open... you can use a screw driver to make and break the circuit. this will cause the coil to arc...

UGLY OLDS

Quoteclean the point contacts with rubbing alcohol or brake cleaner,  the manufacturers have coated most of the sets with clear paint to stop the rusting and corrosion problems that will reduce sales from sitting on a shelf for years...


Some of us have "point files" ,("Gee mister, whats that little file for" ??? ), next to our "lifetime supply" tubes of "rubbing block lubricant" for that very reason...... :lol:

Delco also made a big tube of the stuff.....I still have mine from 196 :?:    :? ...


Bob.... :wink:
1940 Oldsmobile- The "Ugly Olds"
1931 Ford sedan- Retirement project

***** First Member of Team Smart*****

t-vicky

Electronic dist run on 12 volt.  Points & condencer need a resestor to run on 6 volts.

junkyardjeff

I used the factory resistance wire to power the electronic igniton  so the points are getting the correct voltage,before I installed the electronic it did have a tendency to backfire when starting so that should of been a clue something was wrong with the point system.  With new points and condensor its running fine now but I have to deal with the pinion seal that decided to leak on the same trip.  Jeff

38HAULR

If you were running the electronic,I gather this is a proper module High Energy Device,you would not have been getting the full benefit running through the resistance wire,these systems actually draw more current than the conventional points systems ,so the voltage drop would be greater.They need the full 12v. The advance curve of the dizzy can be calibrated by a specialist shop,but a faulty module or one operating not at optimum can also cause advance probs up at the high end. Yes the loose capacitor connection will be like no capacitor and points will burn. I forget which way it goes now,but you can actually check for over or under value capacitor by inspecting the points and seeing which contact has the build up on it[ one side will have a mound,the other a hollow] this happens over time under normal operating conditions........Frank.

junkyardjeff

The motor in question is a 302 ford I have in a 65 custom 500 and I had a factory late 70s duraspark ignition in it which is designed for a smog motor and the motor I have is a very low mile 1970.  I was told that if the #7 and 8 plug wires are touching it will ping badly but before I install it again I will have the advance set like the original distributor.   Jeff

38HAULR

Jeff .I would say the later electronic dizzy will be far superior to the points unit,I would get it re graphed, if required to suit the non pollution motor,definitely would have been strangled running via the ballast though.......Frank.

wayne petty

Quote from: "junkyardjeff"The motor in question is a 302 ford I have in a 65 custom 500 and I had a factory late 70s duraspark ignition in it which is designed for a smog motor and the motor I have is a very low mile 1970.  I was told that if the #7 and 8 plug wires are touching it will ping badly but before I install it again I will have the advance set like the original distributor.   Jeff


over  the front of the drivers side valve cover...  the forward 4 wire separator needs to have the wires in this order...  7,5,6,8  this moves them apart for long enough to stop the induction between the wires...  fords and chevys have this problem with 2 cylinders next to each other in the firing order and in the block...

have you ever noticed on long runs of high voltage wires on poles ... they switch around once in a while..  this removes the ability for induction voltages to cross over..    on signal circuits they twist the pairs of wires to avoid this....

oh....  on ford dizzys.. you can reach in through the square hole and bend the tabs to change the spring tension on the mechanical advance...  

if you have one of those new fangled timing lights  with the ajust knob on the back... a digital tach... a vacuum gauge or a hand vacuum pump you can figure out how much and when... then compair it to earlier spects..

you may have to swap the vacuum advance for an ajustable  unit...

this is a lot harder than it sounds... but once you get it... it is not...  the light will go on.. the power will come back... and everybody including the tire salesman will be happy....

Skip

Quote from: "UGLY OLDS"
Quoteclean the point contacts with rubbing alcohol or brake cleaner,  the manufacturers have coated most of the sets with clear paint to stop the rusting and corrosion problems that will reduce sales from sitting on a shelf for years...


Some of us have "point files" ,("Gee mister, whats that little file for" ??? ), next to our "lifetime supply" tubes of "rubbing block lubricant" for that very reason...... :lol:

Delco also made a big tube of the stuff.....I still have mine from 196 :?:    :? ...


Bob.... :wink:

Got a few tungsten point files myself.

Be careful, though.  Filing points should be used for emergencies ONLY.
Points want to have a nice, shiny, surface.  Point files leave sharp, pointy, ridges and that's the opposite of what you want.

Why do I have so many point files, you ask?  I use them to file down spark plug electrodes to get them flat again.  Domed electrodes don't work that well.
Skip

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