Car starts great then dies 30 secs later - ????
11-12-2016, 06:49 AM
#12
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Join Date: Aug 2014
Location: Tyler/Tx/South/USA
Posts: 51
if it runs great for 30 sec then dies its not a carb issue.
still check for vac leaks but that seems inconsistent with the runs great part now as well.
fuel delivery is most suspect at this point....Ignition is second. Start with fuel delivery.
So fire it up and run until it dies. once it dies do not attempt to restart it. Take off the air cleaner and look down the primary throttle barrels on the carb. Apply full throttle while looking down the carb. You should see a good solid stream of fuel from the accelerator pump as you apply full throttle. Try this 3x in a row. If you get one good stream of fuel on the first try and little to nothing on the next attempts or nothing on any attempts this indicates that carb has run out of fuel and there is no fuel available to run the accelerator pump let alone the engine.
still check for vac leaks but that seems inconsistent with the runs great part now as well.
fuel delivery is most suspect at this point....Ignition is second. Start with fuel delivery.
So fire it up and run until it dies. once it dies do not attempt to restart it. Take off the air cleaner and look down the primary throttle barrels on the carb. Apply full throttle while looking down the carb. You should see a good solid stream of fuel from the accelerator pump as you apply full throttle. Try this 3x in a row. If you get one good stream of fuel on the first try and little to nothing on the next attempts or nothing on any attempts this indicates that carb has run out of fuel and there is no fuel available to run the accelerator pump let alone the engine.
11-12-2016, 07:58 PM
#13
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Location: Hills of California
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did it start right back up or did it fight you after you did the test?
DO you have a timing light? You can stick that on plug 1 and use it as a spark test light...If the coil is breaking down it should stop producing spark which should shut the timing light off...keep the engine rpm up to like 1500 to 2k you should have a nearly steady light...if it goes out and the engine revs down and stops you know it spark.
Did you check for vac leaks yet as well?
DO you have a timing light? You can stick that on plug 1 and use it as a spark test light...If the coil is breaking down it should stop producing spark which should shut the timing light off...keep the engine rpm up to like 1500 to 2k you should have a nearly steady light...if it goes out and the engine revs down and stops you know it spark.
Did you check for vac leaks yet as well?
11-18-2016, 08:22 AM
#14
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Join Date: Aug 2014
Location: Tyler/Tx/South/USA
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Won't start at all now!!
Here's the latest. I drained the fuel tank (replenished with high octane fuel), blew out the fuel line, checked the fuel filter. No sign of crud or issues.
It seems that gradually the car has been getting more and more difficult to start. So now it won't start at all. After checking the fuel system and trying to start the engine I verified that plenty of fuel is present at the carb.
I don't even get firing on any cylinder now! I did have the plug wires pulled from the distributor because I put in new plugs but I don't think I made a mistake putting them back, triple checked, unless I mis-located where number 1 is located on the dist.
I'm going to check for spark at the plugs next - need my lovely key turning assistant for that unless I want to hot wire at the relay. Could it be that the coil was going bad all along?
As for where number 1 is located - I manually turned the engine to get the mark on the balancer lined up with the 0 mark on the timing scale. That should get me where number is going to fire, right? I then removed the dist cap but the rotor seems to be pointing to a spot in between where I determined number 1 should be, and number 8 which is last in the firing order. Why is it in between and not pointing right at number 1?
It seems that gradually the car has been getting more and more difficult to start. So now it won't start at all. After checking the fuel system and trying to start the engine I verified that plenty of fuel is present at the carb.
I don't even get firing on any cylinder now! I did have the plug wires pulled from the distributor because I put in new plugs but I don't think I made a mistake putting them back, triple checked, unless I mis-located where number 1 is located on the dist.
I'm going to check for spark at the plugs next - need my lovely key turning assistant for that unless I want to hot wire at the relay. Could it be that the coil was going bad all along?
As for where number 1 is located - I manually turned the engine to get the mark on the balancer lined up with the 0 mark on the timing scale. That should get me where number is going to fire, right? I then removed the dist cap but the rotor seems to be pointing to a spot in between where I determined number 1 should be, and number 8 which is last in the firing order. Why is it in between and not pointing right at number 1?
11-18-2016, 08:32 PM
#15
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Join Date: Dec 2005
Location: Hills of California
Posts: 5,208
It could absolutely be ignition.
The zero mark will land on TDC compression (where it fires the spark) and TDC exhaust which if you removed the dizzy cap would have the rotor pointing 180 away from plug wire 1.
We want TDC Compression so if its on the zero mark the metal end of the dizzy rotor is close to plug wire 1 then yes thats TDC compression...It doesn't line up exact because the distributor is set to probably 10 to 12 deg advance before TDC. This causes the spark to ignite the fuel 12 deg early so that it is reaching burn rate at TDC mark...It takes time for the fuel to burn so starting the burn early helps it keep up with piston velocity.
I would just pull the coil wire off the coil...Place something like a wrench above it about 1'" and make sure the other end of the wrench is grounded. Crank it over you can watch from under the hood gap maybe if you coil is in the right place...The spark should jump from the coil to the wrench...If not then spark is suspect. It should be a bright blue snap...if its yellow or not at all then yep...good chance.
The zero mark will land on TDC compression (where it fires the spark) and TDC exhaust which if you removed the dizzy cap would have the rotor pointing 180 away from plug wire 1.
We want TDC Compression so if its on the zero mark the metal end of the dizzy rotor is close to plug wire 1 then yes thats TDC compression...It doesn't line up exact because the distributor is set to probably 10 to 12 deg advance before TDC. This causes the spark to ignite the fuel 12 deg early so that it is reaching burn rate at TDC mark...It takes time for the fuel to burn so starting the burn early helps it keep up with piston velocity.
I would just pull the coil wire off the coil...Place something like a wrench above it about 1'" and make sure the other end of the wrench is grounded. Crank it over you can watch from under the hood gap maybe if you coil is in the right place...The spark should jump from the coil to the wrench...If not then spark is suspect. It should be a bright blue snap...if its yellow or not at all then yep...good chance.
11-21-2016, 04:58 PM
#16
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Thread Starter
Join Date: Aug 2014
Location: Tyler/Tx/South/USA
Posts: 51
Checking the ignition system
It could absolutely be ignition.
The zero mark will land on TDC compression (where it fires the spark) and TDC exhaust which if you removed the dizzy cap would have the rotor pointing 180 away from plug wire 1.
We want TDC Compression so if its on the zero mark the metal end of the dizzy rotor is close to plug wire 1 then yes thats TDC compression...It doesn't line up exact because the distributor is set to probably 10 to 12 deg advance before TDC. This causes the spark to ignite the fuel 12 deg early so that it is reaching burn rate at TDC mark...It takes time for the fuel to burn so starting the burn early helps it keep up with piston velocity.
I would just pull the coil wire off the coil...Place something like a wrench above it about 1'" and make sure the other end of the wrench is grounded. Crank it over you can watch from under the hood gap maybe if you coil is in the right place...The spark should jump from the coil to the wrench...If not then spark is suspect. It should be a bright blue snap...if its yellow or not at all then yep...good chance.
The zero mark will land on TDC compression (where it fires the spark) and TDC exhaust which if you removed the dizzy cap would have the rotor pointing 180 away from plug wire 1.
We want TDC Compression so if its on the zero mark the metal end of the dizzy rotor is close to plug wire 1 then yes thats TDC compression...It doesn't line up exact because the distributor is set to probably 10 to 12 deg advance before TDC. This causes the spark to ignite the fuel 12 deg early so that it is reaching burn rate at TDC mark...It takes time for the fuel to burn so starting the burn early helps it keep up with piston velocity.
I would just pull the coil wire off the coil...Place something like a wrench above it about 1'" and make sure the other end of the wrench is grounded. Crank it over you can watch from under the hood gap maybe if you coil is in the right place...The spark should jump from the coil to the wrench...If not then spark is suspect. It should be a bright blue snap...if its yellow or not at all then yep...good chance.
Question - does more voltage going into the coil mean LESS voltage produced when the points open? I would think it would be the other way around.
I also tested for spark at the center of the dist cap where the wire comes in from the coil - not much in the way of spark, and not even producing spark most of the time. But I should say that my testing was a little hit and miss since I was in the car to crank the engine. So, not 100% sure of my spark test and I will work on it again tomorrow.
For now, does anyone know the answer to the question about more voltage coming into the coil and whether it will make more voltage or less, or perhaps short circuit the coil? Thanks!
11-22-2016, 10:34 AM
#17
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Join Date: Apr 2014
Location: PA
Posts: 424
Unless the points are closed, the voltage will read 12 volts because there is no current flowing in the resistance wire. Your meter doesn't draw enough. The pink wire is jumped by the starter solenoid during starting to supply 12 volts to the coil when the points are closed. With the car running you will only have an average of 6 volts because of the pink resistance wire. 12 volts will give a hotter spark, unfortunately 12 volts all the time, will overheat the coil and cause it to breakdown.