Club 80-90 Forums

so have finally got round to looking at the van again

Battery is new...

leads and terminals are good....

Checked for a spark at the plug and am only getting a very weak orange one when the engine is turned over. Any ideas what this means ??

cheers

Have you rechecked voltage at the coil again

How did the van turn over - was it fast or lethargic ?

Do you get the same weak spark with another HT lead ?

I'm thinking voltage drop to starter, voltage drop to coil, or problem in the ignition system, so you will need to methodically work your way through.

just rechecked voltage at the coil and i'm still getting a best reading of 11.2, is this ok?

Van turned over same as always, pretty quick, definitely not lethargic. And i am getting the same weak yellow/orange spark with other ht leads.

so where do i begin with the checks?

I would say that 11.2 volts is not enough. If the engine is turning over quickly then it seems as though starter, feed and earths are fine

Can you run a temporary wire direct from the battery to the coil and see what the voltage is then. Let us know the battery voltage too.

Hello,

It's my day off..and it looks like we will have good tinkering weather...

11.2 volts is a no no.

As you have a powerspark dizzy and coil, all you need is a small power supply to the coil..

A 12 volt scooter battery and small crocodile clips will do fine..

If your new battery has just been fully charged then it should read anything up to 13.4 volts, minimum for a healthy battery is 12,6, discharged 11.8.

A bright blue spark should be seen..

I may fit my 'Rowlsey' mirrors today..

Air-Cooled Bliss.....

Cordialement,

just measured the battery and it has a voltage of 12.8 so thats good, but again tried the coil and only got 11.16 this time.

if i was to add a 12v scooter battery into the mix how exactly does it need to be installed, does it need to be earthed and which wire go where?

Is there no way of fixing the problem without adding an extra battery?

Hope the mirror fiting went well

cheers

No need for another battery, just a length of wire which will help diagnose where the problem is.

12.8 at the battery, 12.6 at the end of the wire, 11.1 on the original connection means voltage drop through the wiring or ignition switch.

if i get some wire and test it do i just connect one end to the + terminal on the battery and the other end to the + terminal on the coil? also do i need to disconnect any wires on the coil before testing?

Just remove the +ve connection (terminal 15 on the coil), and replace with the wire you have.

First test the battery voltage and then voltage at the coil end of the wire, then attach to terminal 15 and see how the spark looks on a spark plug.

Report your findings back and we'll give more advice based on those results.

Don't allow the wire to be wag around and contact earth, it's an unfused test wire.

Hello,

937carrera wrote:
Don't allow the wire to be wag around and contact earth, it's an unfused test wire.

Er..maybe at least an insulated spade female..

or go mad and put a fuse in line..

(Hence scooter gel battery and test clips being part of the kit)..

Aircooled Bliss..

Cordialement,

ok, so have just finished my testing and these are the results:

with ignition off i got 12.8v at battery....... 12.72v at the end of the wire and 12.25v at the coil

with ignition on i got 12.4v at battery........12.15v at the end of the wire and 11.87 at the coil

battery was fully charged before starting. ( did used an insulated spade female on the test wire )

i am still only getting a weak yellow/orange spark at the plug with the test wire connected.

what does all this mean then????

Aircooled annoyance now !!!!!!!!!!!!!

Well, you have confirmed that the van wiring seems to be in OK condition from the battery, through the ignition switch ( which can cause problems) to terminal 15 on the coil.

You have previously worked back from the plug and confirmed all the HT leads are behaving the same, so the problem is between those two ends.

That means all that is left is:
Coil
Ignition amplifier
Distributor including hall sender and cap
HT lead from coil to dizzy.

The coil can be tested by looking for resistance on each of the circuits. Someone on here will know the correct values. Similarly for the HT lead. You could simply check the resistance of the main lead and compare to one of the HT leads. Inspect the dizzy cap to make sure it is intact without cracks or arcing.

Those are free checks though as I believe these are new items I would guess they will all check out fine.

Most likely suspect will be the ignition amp - is that also new, I am not sure that can be tested other than by swapping with a known good one. Do you have an old spare

Apologies for the quick reply, I need to be somewhere else , others will be along shortly

so and update on the progress...

Change the distributor cap and rotor arm and am now getting a good big blue spark, but still can't get the van to start.

Had a friend come out and help we have found that after trying to start the van and taking the spark plugs out, sometimes they were wet with fuel, sometimes not. So now the think is that maybe the fuel is'nt getting from the carbs to the engine/spark plugs. So i'm assuming the carbs have got blocked over the winter when i haven't run him.

Does this sound plausible?

Good, electrics sorted.

The fuel in the carbs has probably evaporated.

Pour an eggcup of fuel into the top of the carbs and try to start. It will run for a few seconds then run out of fuel. Repeat a couple of times and then the pump should be feeding the carb.

Make sure there is fuel in the tank first

There's fuel coming through to the carbs, i have checked and can see it coming through. But it doesn't seem to be getting to the engine for the van to start. Spark plugs are dry.