iginition problem

Sjorz · Post by **Sjorz** » Wed Dec 31, 2008 10:08 am

After replacing the cylinder heads, the 3,5 v8 with a dizzy with a amplifier behind the coil won't start.
I have checked the following parts:
- ignition timing;
- resistance of the pick-up module (3200 ohm);
- If i left the engine off with ignition on and wiggling the rotor on the distributor, the ht-lead will spark when hold nearby ground.
- When I let the engine cranking, no spark and no current at the + side of the coil,after releasing the key again current
- When I set the ignition of and a test bulb between the + of the battery and the - of the coil a measure more than 12 volt.
- When I tried to adjust the timing statical with a test bulb (between - of coil and ground) I always have a burning bulb, only with some wiggling on the rotor a see some difference in the bulb light strength!!
Is there anybody who can give me some advice??
In participation thanks.
Sjorz

Paul B · Post by **Paul B** » Wed Dec 31, 2008 4:42 pm

Sjorz wrote:After replacing the cylinder heads, the 3,5 v8 with a dizzy with a amplifier behind the coil won't start.
I have checked the following parts:
- ignition timing;
- resistance of the pick-up module (3200 ohm);
- If i left the engine off with ignition on and wiggling the rotor on the distributor, the ht-lead will spark when hold nearby ground.
- When I let the engine cranking, no spark and no current at the + side of the coil,after releasing the key again current
- When I set the ignition of and a test bulb between the + of the battery and the - of the coil a measure more than 12 volt.
- When I tried to adjust the timing statical with a test bulb (between - of coil and ground) I always have a burning bulb, only with some wiggling on the rotor a see some difference in the bulb light strength!!
Is there anybody who can give me some advice??
In participation thanks.
Sjorz

The engine has to be turning to make the ignition rotor operate, something about magnetic fields and all. it shouldn't really work just by wiggling the rotor.

Did the motor run before you changed the heads?

It sounds like you have a wire mixed up, if you have no current to the ignition when cranking, but have it when stopped. What wires did you moved when changing the heads?

mgbv8 · Post by **mgbv8** » Wed Dec 31, 2008 5:20 pm

Would this engine have a ballast resistor in the coil circuit?

On my car the ballast is bypassed to give 12 volts to the coil while cranking, then goes back via the resistor when you let the key go after she starts. If it is ballasted maybe you have lost the ballast bypass feed.

Eliot · Post by **Eliot** » Wed Dec 31, 2008 6:49 pm

Sounds like its wired up wrong - this is retrofit presumably.
Many looms will drop 12v to all accessories whilst cranking to ensure all battery power is used on cranking. So the fact that you are also seeing your 12v dissapear whilst cranking tells me you are plumbed into that part of the circuit (via a ballast, if you are running a ballasted coil)
On a rover engine, there is an extra terminal on the starter motor (the smallest one) that feeds 12v direct to the coil whilst cranking.

As a test run a 12v feed direct to the coil and see if it starts. Additionally See if the coil gets hot, if it does - then it needs a ballast.

ramon alban · Post by **ramon alban** » Wed Dec 31, 2008 7:49 pm

Paul B wrote:The engine has to be turning to make the ignition rotor operate, something about magnetic fields and all. it shouldn't really work just by wiggling the rotor.

I'm not sure about that Paul.

If there is sufficient rotary or other deflection for the reluctor coil to be energised by the magnet moving in relation to the pickup then it could/would trigger a spark from the coil dont you think.

Hello Sjorz, So, that symptom you describe also suggests that both the amplifier and the ignition coil are operating OK. Also - so is the pickup coil. Otherwise, no spark can occur. So where can the fault be?

Maybe in the reluctor gapping.

Maybe with the dizzy cap

Maybe with the rotor arm

Maybe with a broken ignition switch that disconnects the 12 volts to the coil whilst cranking

Maybe the coil has a ballast resistor wired in when it is not needed for a 12 volt coil so there is insufficient coil energy (voltage) whilst cranking.

Check your functional circuit integrity - it should be something like this for the key ignition components.

Ian Anderson · Post by **Ian Anderson** » Wed Dec 31, 2008 8:59 pm

Try a push / bump start
If it starts I would think you have the ignition switch wired incorrectly

Ian

Sjorz · Post by **Sjorz** » Wed Dec 31, 2008 9:46 pm

Thanks for your reply all.

The engine run before I changed the heads and I don't think there is a ballast resistor.

By mine knowledge I haven't mixed up some wires, the are two thin cables coming from the starter (black to baseplate of amplifier behind coil and white to + of coil). And two cables coming from the amplifier box to the distributor.

I have put a extra battery connected to earth and on the + of coil, also without success.

Can I remove the innards of the aluminium box except the actual amplifier? (resistor and condenser) I have seen a picture of a almost empty box.

Is it normal that you have always current on the - terminal of the coil? In the old days with points that was the way to set the timing static.

The car (110 Landrover). is at the moment without radiator for easy access so a jump-start is not possible at the moment. In a Haynes manual is a testing procedure and one of the test is putting a multimeter between the positive pole of the battery and the - side of the coil you must not reed any voltage, I mine case I measured the full 12,6 Volts!!

Anyway thanks already a lot for thinking with me and the best wishes for 2009!

Paul B · Post by **Paul B** » Thu Jan 01, 2009 2:27 pm

Sjorz wrote:Thanks for your reply all.

The engine run before I changed the heads and I don't think there is a ballast resistor.

By mine knowledge I haven't mixed up some wires, the are two thin cables coming from the starter (black to baseplate of amplifier behind coil and white to + of coil). And two cables coming from the amplifier box to the distributor.

I have put a extra battery connected to earth and on the + of coil, also without success.

Can I remove the innards of the aluminium box except the actual amplifier? (resistor and condenser) I have seen a picture of a almost empty box.

You can junk everything in the box apart from the amplifier. I did it on my last car and there is a thread in this section about it too. In fact I put the amp outside the box, for easier access.

You just have two wires from the dizzy going to the amp, then two from the amp to the coil, plus a power line to the coil from your ignition switch that supplies power when you turn your key to the 'on' position. Nothing from the starter, no ballast resistor.

http://www.v8forum.co.uk/forum/viewtopic.php?t=78

Sjorz · Post by **Sjorz** » Thu Jan 01, 2009 11:30 pm

Thanks Paul,
Tomorrow a will clean out the old box and take a new wire from a healthy point to the coil + ve .
At the moment I am charging the battery and let you all know what the results are tomorrow!!
Regards,
Sjorz

Sjorz · Post by **Sjorz** » Fri Jan 02, 2009 5:22 pm

Today I have take out all unnecessary stuff out the aluminium box behind the coil and connect a extra battery to the car and after long starting the engine came to life!!
I have also put a new coil on and cleaned the dizzy with a complete aerosol of brake-cleaner!
Still I am not very satisfied with the strength of the spark of the plugs. But at the moment I leave that.

Thank you all!!

Paul B · Post by **Paul B** » Sat Jan 03, 2009 3:01 pm

Sjorz wrote:Today I have take out all unnecessary stuff out the aluminium box behind the coil and connect a extra battery to the car and after long starting the engine came to life!!
I have also put a new coil on and cleaned the dizzy with a complete aerosol of brake-cleaner!
Still I am not very satisfied with the strength of the spark of the plugs. But at the moment I leave that.

Thank you all!!

Great news! Glad you got it sorted. Make sure you have a strong 12volt supply, not through a ballasted wire.

There are loads of after market amplifiers available to give a better spark. The amp from a Chevy HEI unit is the same as the Rover uses, and there are loads available, from somewhere like Summit racing.

Check out this link: http://www.bronco.com/cms/node/25

http://www.summitracing.com

Pertronix Flame-Thrower # PNX-D2000
Pertronix Flame-Thrower # PNX-D2070
ACCEL # ACC-35361
Mallory # MAA-607
Proform # PRO-66944C
Summit's # SUM-850100

ps. make sure the amplifier is always bolted solidly and cleanly to a good earth. Mine is good, as it still bolts to the aluminium casing, which is also earthed with a wire.

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