2.0 djet

Cooler weather here in the Valley (CA) lately...been driving the teener all over!

Yesterday, pulled out of my garage, down around the block and I start to take off at a stop sign and the engine died. I figured I just didn't feather the clutch enough since the motor was cold.

Go to restart...just crank, crank, crank.

I'm getting fuel at 29psi...but no spark out of the coil (zipo). All the connections look good. Disconnected the wires from the Pertronix and checked for voltage at the coil. I checked and I have 12 volts to the positive side of the coil but when I checked the negative side of the coil and the battery (+) I only had 9 volts?? Does this sound like the harness isn't grounding?

Inspected the cap and rotor...look good other than some black dust from rotor to cap wear. The pertronix unit looked good, no smell like it was fried. I never left the key on for more than a momemt when the engine died.

The Bosch blue coil is about 1yr old.

My first guess in the Pertronix went bad, but it's only a couple months old and looks good.

Second guess....something to do with the low voltage on the negative side of the coil.

Looking for some ideas...thanks

The Pertronix needs the ballast resistor to the pos of the coil to work correctly if I remember correctly. 9V is right on if the engine is hot. 12V if the engine is cold.

pull a plug and ground it and check for bright blue spark.

I didn't check the voltage until the car had sat most of the day in the sun...which gets pretty warm..whether or not that simulates a warm engine to the pertronix, I don't know.

I had pulled the coil wire that feeds the distributor and put it close to ground to check for spark...zippo!

I have an extra coil...that's an easy swap to see if it's the problem...I doubt it but.

but checking at the plug will verify that the entire spark path is working correctly.

i just found that the center carbon "button" that comes in contact with the rotor broke off after a plug wire replacement and I didn't' notice it until i tried to start the car.

when was the last time you replaced the plugs/rotor/cap/wires?

I agree checking at the plug end is a good idea...but until I get spark out of the coil, I can't see how checking at the pug end will help.

I'll check the button...it appears to be there but perhaps it has worn down to the point that it isn't making contact any more.

The plugs are new (100 miles), the cap and rotor look good but I'm not to sure their age--they came with the rebuilt motor.

Well, I looked closely at the dizzy cap button and compared it with an old one that I had..and sure enough the button was almost completely ground down on the dizzy in my car. I don't know if it broke off or just has been ground down with wear and finally got to the point of no contact. Anyway off to flaps for some new parts...

Oh, I missed your "Zippo" part on your problem description....

If there's no spark and you've got 9 to 12V getting to the (+) terminal on the coil then there's an issue with the coil not getting triggered.

The job of the Pertronix is to ground the (-) terminal on the coil which in turn induces a high voltage in the coil.

I have heard of Pertronix triggers going bad.


BTW, the 9V is not measured at the (-) terminal of the coil. It is measured at the (+) terminal of the coil.

When you turn on the ignition switch 12V goes to the coil. 12V gives the coil plenty of juice to make big sparks for cold startup situations. If the coil was to continue getting 12V it would eventually burn out.

So it was determined (by someone way smarter than me) that if a ballast resistor was placed inline of the wire feeding to the coil, which reduced voltage to around 9V after it heated up, would help with coil longevity. There are 2 types of ballast resistors that I know of. One is built into the wire and the other is an external type like I have.

I hope this helps.

Roger
PS, the sun will not heat your ballast resistor enough to lower the voltage of your (+) terminal. Only voltage running through it will heat your ballast resistor enough to get the voltage drop.

Bummer...replaced the cap and rotor and still no sparky. You are correct...the coil is not beig triggered. If I had points I would think my points were not opening and closing, but I don't so suspect the Pertronix unit has gone south.

Tried my spare coil with no luck...same....no sparky.

BTW I keep saying Pertronix but it is actually a compufire ignitor, not that it matters much. No ballast was part of this kit..which ain't cheap.

Well, as I see it I have two choices:
1) Buy another ignitor and hope it solves the problem and last a lot longer, this one was only a couple months old..I'm sure there's no warranty on such an electric part.

2) Go back to points...cheaper experiment than the ignitor, although I like not having to fool with points.

Thanks for all the ideas

points cost 4 bucks.
I change mine twice per year.
You only need to set them once.

They never ever ever leave you on the side of the road.
I can buy alot of point for the cost of another petronix thing.

Rich

Yeah..I'm on my third pertonix in 2 years...I could of bought a lifetime suppy of points for every 914 on the West Coast!

Put some points in it and drive. Or go with an optical setup...