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No spark after points change

 
wally0143
My first time was in a Chevy
Posts: 186
Joined: 07/09
Posted: 05/19/11 06:56 PM

I put a new set of points in my chevelle (Borg warner made in USA) and now it seems I have no spark. I pulled a wire and stuck a plug in it and grounded it to the engine while my brother cranked it. No spark. So I put the points that were originally in when the car ran, and got the same result. Then I put in a spare condenser and still nothing. I checked to make sure all the wires are tight and the rotor is on right. What gives? I have done this a hundred times and never had this problem!  
Nobody knows everything but everybody knows something

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 05/20/11 09:13 AM

MAKE SURE THE BATTERY VOLTAGE IS UP ESPECIALLY ON A POINT DISTRIBUTOR IGNITION.14.7 Volts DC. Watch where the voltage goes when you crank the engine. If it drops below 12volts DC. Either charge the battery and load test it. How old are the ignition wires? Wally: Spark isn't made at the points. It's made at the coil. Go back there first. Is there spark coming from the coil wire while cranking the engine? It is very possible that when you took the distributor cap off you accidentaly broke the coil wire internally. Check that the new/old points aren't grounding. Check the dwell if memory serves me dwell is 28 degrees to 32 degrees if a V8 engine. Shoot for the 30 degrees. Or a .016 to .019 feeler gauge. Check the positive and negative wires on the coil. Points give you dwell time in crank degrees between each cylinder being fired. Look at the points if gapped correctly when you crank the engine you should see arching between the point contacts. Check the distribor rotor make sure it hasn't moved or is cracked (seen this before). Just back track your steps. Good Luck....!  

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wally0143
My first time was in a Chevy
Posts: 186
Joined: 07/09
Posted: 05/20/11 07:58 PM

I was already onto the coil checks before I read your reply. There was no spark at the coil wire, so I got a new one and installed it. Still no spark. Checked everything I touched,still no spark. I am hunting for a new coil wire.The wire set on there has maybe 15K miles on it. I am having a hard time finding anyplace that will sell me just a coil wire. I keep thinking of all the ones I have thrown out over the years. Frustrating!!!  
Nobody knows everything but everybody knows something

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 05/21/11 11:44 AM

a few POINTers

new points most of the time now have a protective clear coating that needs to be cleaned off the contacts for the points to work properly...  a shot of brake cleaner on a Q-tip... or just spraying across..

there is a ground wire from one of the vacuum advance hold down screws and goes under one of the points hold down screws... its really important..  follow along..


electrons flow from negative to positive..    when the points close...   electrons flow from the engine block.. to the intake manifold to the distributer housing.. through the ground cable to the upper breaker plate...   through the closed points contact.. up the coil negative wire and through the primary windings building a magnetic field...  

when the points open.. the magnetic field collapses through the secondary winding creating a high voltage spark...


now.. another POINTer..    were is the wire from the coil negative hooked up to????  is it in the proper location..???

if you have a separate condenser..   is it hooked to the same place as the coil negative wire..  without the condenser properly attached .. it won't spark...

if you have the crank shaft positioned... so the points are just about to open..   you can grab the rotor and turn it against the spring tension to cause the points to open...  if the key is on..  and the coil wire set about 1/4" from ground..  it should spark from the end of the coil wire...


you can also use a screw driver when the points are open. to jump across the contacts... to make the coil spark for testing...

if you don't have a dwell meter .. harbor freight has one for 38 bucks..   you can get really close by getting the engine running..     turning the point adjusting screw one way slowly until the engine dies.. then turn it the other direction exactly a half turn..   that should be really close to 30 degrees of dwell...

Image 3330


one last pointer..

set dwell first...   with a dwell meter..  then check the timing..   changes in dwell change the base timing..


a long long time ago..  i drove past a friends house.. the guy next door was out there working on his buick invicta..

he was cranking and cranking the engine..  he had done a tune up and put new points in..  but was getting no spark...

i noticed he had the wire on the wrong side of the spring..   i moved it and had him try it..  as he turned the key on.. there was a HUGE explosion from under the back of the car... so much so that my pants lets were flapping ...  i looked under the back of the car and fell to the ground laughing..  i was laughing so hard my ribs were cramping .. he got out and started to kick me.. stop laughing at my car he kept demanding.. i said how are you going to explain that..  as i pointed to the back of the car..   the brand new midas muffler skin  was completely unwrapped and laying as flat as a piece of newspaper . i could see the diamond shapes in it from the front of the car..  it was not torn at all.. but completely unrolled and flattened out..

all the fuel from his frantic pumping and cranking had filled the exhaust system with enough vapors to really make some noise... usually the exhaust system is full of burned gasses..  not this time..  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 05/21/11 12:52 PM

Wally: Just for a ha ha. Do you have battery voltage at the coil. Just a shot in the dark did you blow the ignition fuse? Does that have the old buss fuse? Maybe you lost the ignition switch. Check that ignition fuse circut. Let us know.  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 05/21/11 01:03 PM

Wally: It takes 8,460 bolts to build an automobile, and only one nut to scatter it all over the highway!  

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wally0143
My first time was in a Chevy
Posts: 186
Joined: 07/09
Posted: 05/21/11 01:50 PM

Heres what I have so far- The condenser is under the cap, and connects to the points. under the screw for the points is the distributor ground. The distributor is hooked to the negative side of the coil, as well as my tach. the positive side has the ignition switch wires. I tested the ohms on the coil wire and it checks out fine. with the key on, I have 5.8 volts on the positive side of the coil. I can't find a fuse that is marked Ignition, nor any blown fuses in the block. Still no spark. Old lady getting pissed because I am screwing with the car and not her.  
Nobody knows everything but everybody knows something

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redneckjoe69
Everything in my driveway’s a Chevy
Posts: 612
Joined: 02/10
Posted: 05/21/11 03:16 PM

curious, shouldnt you have 12 volts on the hot wire going to the coil with the key on?   been a long time since i messed with points.    for the heck of it, try disconnecting your tach if you cant get it figured out.   dang gremlins. Mad  Grin    probably something silly.   if you have my luck, it will be in the last place you look.  

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wally0143
My first time was in a Chevy
Posts: 186
Joined: 07/09
Posted: 05/21/11 06:04 PM

I thought it should be 12 too, joe. I disconnected the tach. Still won't start. I do not think it will be the last place I look, as I am out of places now!  
Nobody knows everything but everybody knows something

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 05/21/11 06:54 PM

Wally: That's your problem,  You should heve battery voltage there. You probably have a ballast resistor inline to the points somewhere . Go to that and see what you have for battery voltage. The resistor is there to cut the voltage down to maybe 11 to 12 VDC. Thats so your not burning points up every 5k miles.Find that resistor and follow the battery voltage.Only one other thing I can think is the wire that goes through the distributor maybe grounding? Don't let it get you!  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 05/21/11 06:59 PM

Wally just thought of something else. Give the wires on the starter a wiggle test. See if any of the wires are green with corrosion  and if so splice a new piece in and give that a try. Sorry Good Luck!  

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wally0143
My first time was in a Chevy
Posts: 186
Joined: 07/09
Posted: 05/21/11 07:46 PM

I have never heard of a ballast resistor on a chevy. My 73 Dart had one, and it was the first thing wrong every time. I wouldn't even begin to know where to look for one , or what it would look like under the hood of my chevelle. I have been working on these cars for 25 years and never had this problem. I missed a whole day of great cruisin weather today.  
Nobody knows everything but everybody knows something

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wally0143
My first time was in a Chevy
Posts: 186
Joined: 07/09
Posted: 05/21/11 07:47 PM

Are you perhaps referring to the condenser?  
Nobody knows everything but everybody knows something

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 05/21/11 07:49 PM

use a jumper wire to supply power to the positive side of the coil for a test...



under 6 volts IS TOO LOW...  

point cars will ONLY have a full 12 volts while the engine is cranking..

9 to 10.7 is normal with the engine running..

let me look at what kind of car you are working on...

in MOST gm cars with points...    

when the key is in the RUN position.. the power comes from the IGN1 wire to the positive side of the coil... this is a resistor wire.. so the load of the coil reduces the voltage to the coil so the points don't burn out...

when the key is in the CRANKING position..  the power comes either from the starter R terminal or the IGN2 terminal on the ignition switch..    either wire will not be a resistance wire.. so the coil will have full battery voltage when cranking...


i have had problems when starters are replaced.. that the bypass wire on the R terminal shorts to ground...  dragging all the power the ignition resistor wire can provide and reducing the voltage like you describe...

i have also had the R terminal inside the starter solenoid cap get out of position..  short to ground.. or worse.. short to the bottom post on the solenoid cap..   this sends all the power the resistor wire can supply right to the starter windings...  preventing the ignition coil from getting enough power to build a big enough spark to let the engine start...

did you post what year and model car you have.. if not.. do so.. i can look up the wiring diagrams i have... so i can give you an exact...  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 05/21/11 07:55 PM

wally please also post the part number from the POINTS box..  i know what brand.. but i want to know which model points.. most manufacturers have 3 or 4 different versions....


Dr1075mv

DR1075MVO

DR1080MV  

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