no spark msd ign

[chris-stockton]

Hello guys. Looking for a bit of help with fault finding. The car is a westfield with a rover v8 in. It has a distributor but a separate msd ign amplifier and an msd coil..

now im getting no spark from the coil. Im getting 12v to the pos side. Ive swapped the coil for a known good one. So where do I go from here. Muat be the switching side.

Magnetic pickup or the msd ign am. Any tests I could do with a multimeter?
Cheers chris

[Eliot]

MSD = My Spark Died....

[Ian Anderson]

MSD = my spark died

I have heard more MSD problems than fixes

Sorry not my cup of tea

Ian

[mgbv8]

I've had no problems with the MSD on either car in the last 8 years?

If you have an MSD coil I guess its a blaster 1 or 2, wet or dry coil.

Is this the first time you have tried to use this system??? Has it already been running??

My initial thought is NO!!!

You should not be able to see 12 volts at the coil +

This should be fed with over 400 volts from the MSD amplifier when triggered via the dissy.

How many wires are coming from the mag pick up ?

I think this is a wiring error from what I have read in your post.

If this stuff is new then review the wiring diagram, or if you dont have that then go to the MSD tech help website and download the diagrams.

Is this an MSD dissy with mag pickup or a Mallory Disst with Mag pickup??

Perry

[chris-stockton]

Hello. The whole system and car has worked fine for about 8 years. So that rules that out. From what I can see on the msd documents, if its configured to use a mag pickup then you should see 12v at the coil +ve.

[mgbv8]

Cool!!

That rules out the wiring as it was already working.

This is the vid of how to test

http://www.msdhelp.com/Testing_your_MSD.aspx

[Eliot]

Hello. The whole system and car has worked fine for about 8 years.

I've had no problems with the MSD on either car in the last 8 years?

I guess yours is due then Pel

[chris-stockton]

hello perry,

ok I carried out the test on the ign amp unit tonight and it sparked ok.

I noticed though that as I crank it, the +ve supply drops to about 6 to 8v on the coil, so I ran a +ve 12 straight from the battery and it was still the same.

Now to confuse it even more - at the start of the night, it was randomly sparking for the first 3 to 4 secs of cranking then nothing.?

ok so where now

[DaveEFI]

hello perry,

ok I carried out the test on the ign amp unit tonight and it sparked ok.

I noticed though that as I crank it, the +ve supply drops to about 6 to 8v on the coil, so I ran a +ve 12 straight from the battery and it was still the same.
[snip]

What are the battery volts measured across the battery when cranking?
If it's 6-8v at that it suggests either a knackered battery and or a knackered starter motor. And there will be a point where the volts are too low for the ignition to work. You could prove this by using a second battery to run just the ignition. I'd not expect battery volts to drop below 9v when cranking.

[chris-stockton]

yeah accross the battery when cranking was about 10 v

on the coil +ve sometimes 6-8v

I ran a +ve feed directly to the coil +ve so it gets about 10v and it was still the same.

I re-adjusted the pickup gap which was 3 times larger than it should be, removed the dizzy, connected it all up with ign on, and manually span the dizzy, it will work for maybe 10 secs at a time, then randomly not work for say 30 secs, then randomly work again.

Something odd here!

[mgbv8]

I'm pretty sure that when the cranking voltage drops to about 10.5-11 volts on our MSD and Mallory AL6 that the spark stops.

On Jays MSD with the ballasted dry coil if the 6 volts drops to 4 it wont spark.