No Sparks

[Grim]

I've been working on the car all day after my breakdown yesterday. Thanks go to Tim Swait who has helped me.

 

I am running a 2.0 efi pinto.

The basic problem is that there are no sparks! It's not the ECU or TFI module, as i was able to switch them. There is power to the engine loom, and the engine is earthed. I've changed the coil with no change.

 

Does anyone have any suggestions? Is it possible for a dizzy to have an internal failure?

[Guest red7]

Oh yes. :boohoo:

 

I had a dizzy die on me a couple of years ago. When I took it apart I found one of the springs had snapped and fallen into the works. Remember the shaft is rotating at high speed and the spring had been flying about in there causing mayhem. There it is in the bottom left of the snap.

dizzy

[steve in stockport]

Andy have you checked the dizzy cap for cracks or whether the centre contact has broken.

are all the electric plugs fully fitted, not just looking like they are in

 

Steve

[Guest Bazwaz]

Have you tried the advice Simon gave in an earlier thread.

Hi,

Does that mean you are on electronic ignition or are you on points??

Either way, lets check if you have enough spark for the job and lets do some basics.

1. Pull the main HT lead out of the cap and get a set of insulated pliers.

Hold the HT lead end about 1/4 inch away from the block and get someone to crank the engine. You should get a good "Blue" spark jump the 1/4 inch gap. This means you have about 20,000 volts jumping at this point.

Whilst still cranking increase the gap to about 1/2 inch. If you are electronic ignition, it will start to flag at about now, but if you are points you probably wont get past 1/4 inch.

One word of warning, when you get to the point were the spark is no longer jumping, it is trying to find an earth anywhere else. Hold all parts of your body away from any metal bits of the car or your hair stands on end and your eyes light up.

If you don't get the jump, then your insulation is breaking down somwhere or your coil is stuffed. It can be handy to check this in the dark as any breakdown in insulation leaves whispy blue sparks at the coil tower.

If you pass this test, move to stage 2.

2. Take distributor cap off. With the main HT lead still held in your pliers, Hold the end about 1/4 inch above the center of the rotor arm. Crank the engine again. The spark should "NOT" jump to the rotor. If it does, your rotor is stuffed.

WARNING- make sure that the cap clips are well out of the way. The favorite here is for the clips to tuck in and catch on the electronic pickups inside the dizzy and put them out of sinc.

3. Put you cap back on, put your main HT lead back in cap and disconect a plug lead. You now have to perform the same spark jump test with the end of the lead.

NOTE- With the "END" of the lead. Not with a plug stuffed in it. It only takes about 5,000 volts to jump the .75mm gap at atmospheric pressure. Under cranking, you need about 15,000 volts at the plug to start. Higher energy in the spark is needed with combustion pressures.

You can either pull back the rubber boot from the plug or stick a 3" nail in the end and jump the spark from the nail.

If you get 1/4 inch jump here, then your problem aint sparks.

Have a good weekend.

Simon

[Andy Spencer]

Last time this happened to me was not on my Hood but years ago in a Chevette - a hairline crack down the centre of the rotor arm. Couldn't even see it.

 

May just be worth swapping the cap and arm as previously suggested, to be sure.

 

Good luck

 

Andy

[Guest chris brown]

May just be worth swapping the cap and arm as previously suggested, to be sure.

A good suggestion we had a car in a few months ago where the rotor arm had broken the peg off (the bit that locates it on the shaft) so it was not pointing in the correct position also had a Porche which broke the drive so the dizy wasn’t turning at all both easy checks and so obvious that most miss them.

[Guest salty_monk]

I've also heard of the insulation breaking down on a rotor arm, it then sends the spark to earth i think...

 

Dan

[Guest timswait]

I'm pretty sure the problem doesn't lie with the high tension side, there's no spark direct from the coil, also the rev counter doesn't flick when the engine is cranked, so I don't think the coil is being switched. (there is 12V on the appropriate side of the coil). We tested the TFI and ECU by running my car with them. To my mind this leaves either the camshaft position sensor part of the dizzy or some bad connection (although we checked a fair few connections).

[Longboarder]

Test the coil with a multimeter. Should have continuity between the + and - terminals with a resistance of just under 1 ohm. Then try resistance between either LT terminal and the HT terminal,should be between 4.5 K and 7 K ohms. If you don't have a meter just hot wire the coil, after disconecting the leads from it. Batt pos to coil pos, bat neg to coil neg, king lead to close to earth. Every time you break the neg circuit you should get a spark.

If you don't the coils gone belly up. If you do then there is a failure in the switching system.

 

Nigel

[Grim]

as Tim says, it's definately not producing a spark from the coil. I did have an HT lead fall off, which could have damaged the electronics in the dizzy somehow?

I've made a post in Wanted for a pinto EFI dizzy.

[Grim]

Right, all is good now!!!!

 

I tested the dizzy, and it wasn't providing a variable output from the hall sensor, so it is the dizzy at fault. So i'm now waiting for the new dizzy!

 

If anyone is interested in how to test an electronic dizzy on the car, here's how (thanks again Tim):

 

1) Test for 12v between the outer two of the 3 wires connected to the dizzy with ignition on.

2) Slide back rubber sheath on connector, connect an led between pins 1 and 2 from the rear of the connector (note leds only work one way around), and reconnect the connector to the dizzy.

3) Ensure the engine wont start by some means

4) Crank engine, and check led flashes, if not, it's broken.

[Guest timswait]

Are you going to dimantle the old dizzy in the mean time, see if you can see what's wrong?

[Grim]

i'll probably take it apart once i get it off, if only for fun. i don't want to take it off before, incase i get muck inside as the car is outside still, plus it'll be easier to switch it if i can remember what position it is in!

[Grim]

i tested the dizzy by connecting it to the loom and earth wire, and span it, and i could hear injectors clicking, and one cylinder fired, dispite me not even cranking the engine, so it' fair to say it will work. Will fit it properly later, when it's not raining (rain was dripping heavily inside the car).

[Guest timswait]

That's good to hear, you should be back on the road in no time - there nicely jinxed you so now you've got someone to blame if it still doesn't work!

Audi were working on a system for starting enignes without using a starter motor, ie just sensing which cylinder was near enough TDC and squirting fuel in and firing it, sounds like you've just invented a system for a Hood!

N.B the Audi system only works on engines with 8 or more cyclinders, and even then only had pistons in the right place to fire 90% of the time.