Still No Spark 1950 8N 12v conversion.

[Soundguy]

ditto what jj said.

you can do a quick go / no go thumb test on each cyl to see if the valves are opening and closing.

post back

soundguy

 

[J_J]

What is your timing ? Is it TDC or so many degrees before TDC. Timing will prevent you starting and work against you by firing sooner then it should.

I used to set timing and check firing on different engines by using an AM radio. When the plug fires, you will hear a pop on the radio. If the timing should be TDC, then you can perhaps see the cyl at TDC or put a dowle rod in the cyl and when you turn the engine over slowly, if the timing is set correctly, when the cyl is TDC, the points will open and the plug will fire.

You do know the purpose of firing off the plug before TDC, advance timing, and that is to spark the mixture and allow the mixture to ignite and start burning before TDC which will give the most power out of the gas mixture when the cyl is at the top of the stroke. .

I actually had one engine that retarded the spark which was in a turbocharged Corvair.

 

[2LateIWon]

This is what boggles my mind. It was working perfect and supper strong. I was brush hogging a field (I only had about 5 acres left ) and I noticed it start to loose power. By the end of the day it could hardly cut in first gear full throttle. It sounded like it was missing. So I loaded it up took it home put new points and condenser in and haven't got spark since then. (I put new spark plugs on right before I mowed this property) Until just the other day thanks to JJ and Soundguy. So last night I tried changing back to the old cap and rotor to see if that changed but sill no go. So put new cap rotor back on. I took the spark plug out of #4 put my thumb on it and it blew it off. I poured a little gas in the hole and still nothing. So I've never messed with the timing. Theoretically after I got spark it should have started right back up. Now I'm completely dumbfounded. So agin thanks guys for hanging in there with me.

 

[jinman]

Ok Firing order is correct. and gap is good...... after about 5-10 seconds trying to start nothing after the 3rd or 4th try I get a back fire. I don't get it.

Pull your coil wire out of the top of your dist cap and hold it near ground while turning over the engine. If it arcs regularly, then everything is good up to and including the points. If not, then the points and before are still a problem. If the spark from the coil wire is good, put it back into the distributor and pull the No.1 plug wire and look for a spark as the engine turns over. It should spark at 1/4 the rate of the coil wire. If there is no spark, then your cap is not seating properly or the rotor button is not seated properly. Make sure the inside of the dist cap is clean and dry and it is seated all the way down. If you have a points cover under the rotor button, make sure it also is seated properly. It doesn't take much out of position of the dist rotor or cap to cause big problems.

 

[JC-jetro]

Additionally you can buy HF Inline Ignition Spark Checker to figure out if you get spark up to the plugs. It is very convenient to use and needs no tools at all.

JC,

Inline Ignition Spark Checker

 

[2LateIWon]

Good point about the speed of spark from the coil to the #1 cyl.

Thanks I actually bought the spark plug light/tester from HF just for this LOL ( I needed to buy one anyways) It works great

 

[JC-jetro]

Good point about the speed of spark from the coil to the #1 cyl.

Thanks I actually bought the spark plug light/tester from HF just for this LOL ( I needed to buy one anyways) It works great

I had an unreliable feed back from my Jeep's Crank Position Sensor that was totally random and a holy pain in you know where. The tester really helped me to diagnose. Changing the CPS was another lovely experience

JC,

 

[V1Rotate]

Do you think there might be two problems going on at the same time? By that I mean it seems that you have the ignition problem solved (maybe) but what about a fuel problem? Do you think the initial power loss might have been caused by bad fuel or dirt in the carburetor and now that fuel problem might be causing it to not start?

Just taking some shots in the dark.

 

[2LateIWon]

Do you think there might be two problems going on at the same time? By that I mean it seems that you have the ignition problem solved (maybe) but what about a fuel problem? Do you think the initial power loss might have been caused by bad fuel or dirt in the carburetor and now that fuel problem might be causing it to not start?

Just taking some shots in the dark.

I wouldn't doubt that at all. I'll pull the plugs again and actually put fuel down in each cyl and see what I get.

 

[Soundguy]

I had an unreliable feed back from my Jeep's Crank Position Sensor that was totally random and a holy pain in you know where. The tester really helped me to diagnose. Changing the CPS was another lovely experience

JC,

not an apples to apples comparison.. but did make me think about it.. a ford powerstroke diesel has a cps sensor that will up and quit and leave you on the roadside..... the cps ( cam sensor ) on a ford diesel is easy to change.. cut the wheel hard tot he side and a lil tab with 1-2 bolts hold it in.. unplug and plug new one it. like a 20$ part.. yet.. it will elave you walking on the roadside.. most powerstroke owners I know carry one in their glove box just for this reason..

soundguy