electrical and ignition Weak Spark - 6Kv Drop from coil to Plug

[math labs]

Hello friends, 

 

Just got my Ireland Engineering dizzy after replacing the old ignition setup (old setup was a Autotonic photo sensor trigger wheel). I've been having a hard time getting the car to fire (weak spark). Chasing the gremlins I decided to just replace anything that made sense. 

 

• New Plugs - BP6E5
• New Bosch Wires
• New Ireland Engineering distributor
• New Vatozone Coil

 

My buddy came over with some tools and after seeing a very weak arc on the spark plugs, we found that;

 

At the coil to distributor wire we're measuring 8Kv. At the plug wires we're only mearing 2Kv. The spark is a very tiny spark. 

 

Car is at TDC via crank pulley and cam gear.

 

I can't even get the car to turn over using starting fluid, it stumbles like it wants to start, but doesnt do anything.

 

Could my distributor be out of phase? I want to note that the distributor gear that came with the distritbutor would not mesh - I knocked the old gear off of my old distributor and it slid in and meshed no problem.

 

If anyone could assist, that would be awesome. Thanks in advance! Throwing in a photo of some old SSR's I threw on. 

 

[Stevenc22]

Few things.

 

#1 are you using a Vatozone blue coil? If so make sure you dont have any ballast resistor or resistor wiring in your setup as the blue coils are internally resisted to 3 ohms.

 

Even if you are at TDC, you might need to rotate the distributor left and right to find the sweet spot where it wants to start. Once running you can properly dial in the timing but dont be scared to try 5-10-15 degrees left and the 5-10-15 degrees rotated right. The motor will start to sounds healther and more eager to start as your get closed to the right timing spot and then will finally fire.

 

 

 

 

[math labs]

26 minutes ago, Stevenc22 said:

Few things.

 

#1 are you using a Vatozone blue coil? If so make sure you dont have any ballast resistor or resistor wiring in your setup as the blue coils are internally resisted to 3 ohms.

 

Even if you are at TDC, you might need to rotate the distributor left and right to find the sweet spot where it wants to start. Once running you can properly dial in the timing but dont be scared to try 5-10-15 degrees left and the 5-10-15 degrees rotated right. The motor will start to sounds healther and more eager to start as your get closed to the right timing spot and then will finally fire.

 

 

 

 

Thanks for the heads up! The coil I got is a black coil, but it could very well be internally resisted. I'll check on that too!

[Stevenc22]

Yeah whole system needs 3 ohms of resistance. Check the coil label for its resistance value. If its 3 ohms, then dont use a ballast resistor. If its 1.8 ohms, then you need a 1.2 ohm resistor. ect....

 

I check autozone website. They have multple black coils. Some are 1.5 ohms and one was 3.4 ohms.

[TobyB]

Quote

New Bosch Wires

 

Resistance, resistance, resistance.  I bet your rotor is 5k as well.

 

I've never had a meter that could measure plug peak voltage, but 8kV sounds low...

...an internal resistor in the coil would make that worse.

 

fwiw

 

t

[math labs]

1 hour ago, TobyB said:

 

Resistance, resistance, resistance.  I bet your rotor is 5k as well.

 

I've never had a meter that could measure plug peak voltage, but 8kV sounds low...

...an internal resistor in the coil would make that worse.

 

fwiw

 

t

Thanks T,

 

I'm curious now to know what the standard output should be from the coil, and from the distributor to the plugs. If anyone has that info that would be great

[xferboy]

for interest, what was used to measure the  spark voltage?

 

 

[math labs]

13 minutes ago, xferboy said:

for interest, what was used to measure the  spark voltage?

 

 

we used a snap-on altus diagnostic tool haha overboard for a carb'd car, but it has great tools built into it