620 no sparks from the Dizzy to the spark plugs

[sanyantho]

Hi Ratsun,

    I went on vacation and left my 620 parked for a month and now it won't start. There is sparks from the coil but no sparks from the electronic distributor to the spark plugs.  It was running fine when I parked it. I have changed the cap, rotor, and spark plug wires but still have no sparks. Does that mean my distributor is bad. I have used the search feature to search the forum but have not found any answer. Any advice is greatly appreciated. 

 

Thanks,

Sanyantho

[datzenmike]

 If the coil is sparking when trying to start, then the only thing between it and the plugs is the coil wire, the distributor cap, the rotor and the plug wires.

 

Pull the coil wire out of the center of the cap and hold near a ground. Turn the engine with the starter. Got spark???

 

 

[sanyantho]

2 hours ago, datzenmike said:

 If the coil is sparking when trying to start, then the only thing between it and the plugs is the coil wire, the distributor cap, the rotor and the plug wires.

 

Pull the coil wire out of the center of the cap and hold near a ground. Turn the engine with the starter. Got spark???

 

 

Yes, have sparks

[datzenmike]

Good now pull any spark plug wire off and fit an old plug in the end hold it against a grounded part of the engine. Turn engine with starter and look for spark. Got spark?

[sanyantho]

56 minutes ago, datzenmike said:

Good now pull any spark plug wire off and fit an old plug in the end hold it against a grounded part of the engine. Turn engine with starter and look for spark. Got spark?

No spark

[banzai510(hainz)]

doesnt the dist tell the coil to fire? You said you got spark.

if you got spark out from the center coil wire to ground then I say the dist is good.

the rest is electrical path for the spark to the clylinders in correct order

 

orginal write up is really no start?

 You got gas squirting in the carb?

 

now you put the plug wire correct back on?

 

 

 

[datzenmike]

7 hours ago, sanyantho said:

No spark

 

At plugs.

 

Spark at coil and coil wire to the distributor cap. Problem is under the cap. Rotor most likely.

 

Post pictures of cap, rotor and wires.

[sanyantho]

11 minutes ago, datzenmike said:

 

At plugs.

 

Spark at coil and coil wire to the distributor cap. Problem is under the cap. Rotor most likely.

 

Post pictures of cap, rotor and wires.

i will take some picture soon, I bought new cap rotor and wire tho. Did I buy the wrong parts? They are stock but I have an non original dizzy, not a stock distributor.

[Stoffregen Motorsports]

Ran when parked. Do you have mice or rats around your property.

[datzenmike]

3 hours ago, sanyantho said:

i will take some picture soon, I bought new cap rotor and wire tho. Did I buy the wrong parts? They are stock but I have an non original dizzy, not a stock distributor.

 

The later EI matchbox distributor is compatible with all L 4 cylinder engines.

 

The later L20B distributor cap is larger diameter so I assume the rotor inside is is also. If the earlier '74 rotor is smaller diameter the spark might not jump any gap plus the plug gap. Did you get a '79 rotor???

[banzai510(hainz)]

he said he got spark at the coil. I assume coil wire that went to the centr of the dist cap. The rest is cap to the rotor then to out the corrisponding sparks plug

 

all 4 spark plug wires going BAD?????

Edited March 29 by banzai510(hainz)

[datzenmike]

It was doing the same before the wires, cap and rotor were changed. Makes no sense, hence all the very basic questions.

 

If there is spark at the coil wire then the distributor is fine and working, it's something between the coil and the plugs.

[sanyantho]

7 hours ago, datzenmike said:

 

The later EI matchbox distributor is compatible with all L 4 cylinder engines.

 

The later L20B distributor cap is larger diameter so I assume the rotor inside is is also. If the earlier '74 rotor is smaller diameter the spark might not jump any gap plus the plug gap. Did you get a '79 rotor???

No, i got the '74 cap and rotor

[sanyantho]

2 hours ago, datzenmike said:

It was doing the same before the wires, cap and rotor were changed. Makes no sense, hence all the very basic questions.

 

If there is spark at the coil wire then the distributor is fine and working, it's something between the coil and the plugs.

Yes you are correct, it was doing the same before I changed the cap and rotor

[sanyantho]

9 hours ago, Stoffregen Motorsports said:

Ran when parked. Do you have mice or rats around your property.

I do have rats out here on the farm

[datzenmike]

 

 

 

Again... the coil sparks when trying to start so the electrical part of the distributor and as far as the coil, is working. Spark from the coil is not getting to the plugs. Was running (so wired properly) After fitting it would not start. Cap rotor and plug wires were changed and it didn't help. (which kind of indicates that it isn't cap, rotor or plug wires)

 

  You put an old spark plug in one of the plug wires and definitely held it against the head or something grounded to check for spark ????

[]2eDeYe]

You can eliminate the wires with an ohm meter. 

Is your rotor spinning when you crank the engine over?

[Stoffregen Motorsports]

I didn't read all of this, so I don't know if you've addressed the possibility of a chewn wire, but that's where I would start. Any sign of rats under the hood or in the cab? Tiny little foot prints on the inner fender wells? I get rats and mice under the hood of various trucks around the property. The closer they are parked to the shop, the less of a problem it is.

[datzenmike]

4 hours ago, ]2eDeYe said:

You can eliminate the wires with an ohm meter. 

Is your rotor spinning when you crank the engine over?

 

The coil produces a spark when cranking the engine to start so I assume the coil and distributor are working. Spark is not getting to the plugs.

[sanyantho]

On 3/29/2024 at 9:34 PM, datzenmike said:

 

 

 

Again... the coil sparks when trying to start so the electrical part of the distributor and as far as the coil, is working. Spark from the coil is not getting to the plugs. Was running (so wired properly) After fitting it would not start. Cap rotor and plug wires were changed and it didn't help. (which kind of indicates that it isn't cap, rotor or plug wires)

 

  You put an old spark plug in one of the plug wires and definitely held it against the head or something grounded to check for spark ????

Yes I did that and got no spark. I am going to take picture of the new vs the old cap and rotor. As well take some measurement to see if they are the same size.

[sanyantho]

On 3/31/2024 at 8:51 AM, sanyantho said:

Yes I did that and got no spark. I am going to take picture of the new vs the old cap and rotor. As well take some measurement to see if they are the same size.

On the left is the new cap and rotor. Any difference? Seems like the inside of the cap is different 

[sanyantho]

[sanyantho]

[datzenmike]

See that little carbon button in the middle? that should be spring loaded so it makes contact with the top contact on the rotor.

 

 

Question: when you swap caps, does the wire positions change on top?

[sanyantho]

3 hours ago, datzenmike said:

See that little carbon button in the middle? that should be spring loaded so it makes contact with the top contact on the rotor.

 

 

Question: when you swap caps, does the wire positions change on top?

The carbon button on the new cap come down further than the old cap. When I swap cap the wire position on top stays the same. I will recheck tomorrow to be positive.