MGB & GT Forum

I decided this might warrant a new thread since the old one was more about firing order.

Per the pertronix website Ignitor II modules can not be static timed and I'm having some issues getting the car started.

I began with the distributor vacuum unit at roughly 12 oclock as suggested in another thread and have moved it tiny increments CW and CCW as far as it will go with no start. This is very weird since it did start last week and run OK prior to even having the timing set on it.

Since that start I replaced the plug wires with new pertronix plug wires which is when i found that the firing order was off due to the distributor drive gear being in wrong. I fixed that to find that the drive dog on the distributor was also installed incorrectly. With those things corrected of course the position the distributor was originally doesn't start.

One thing I just noted, after trying repeated starts the anti runon valve is very warm. So just to take that out of the equation I disconnected the vacuum line to it. Don’t have any effect. Plugs smelled like fuel anyway so didn’t think that was the issue.

Any suggestions would be appreciated.



Edited 1 time(s). Last edit at 2026-03-06 12:23 PM by dannyclarke58.

Any reason why you can't have somebody crank the engine over while you shine a timing light at the marks to see where #1 is firing? You can probably even do it yourself if you have a remote starter button.

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Terry Ingoldsby
terry.ingoldsby@DCExperts.com

The anti run-on valve should only have power to it with the ignition in the off position . If you want to disable it unhook the ground wire from it at the oil pressure switch on the bulkhead shelf where presumably you have an adsorption canister. Was unable to tell from your post if you also repositioned the drive dog on the distributor . If not your rotor may be out of phase . Do you get any firing at all ? MGBs have a wide range of timing settings where you can at least get the engine to start. Hook the vacuum hose back up or you will have an unwanted vacuum leak.

RudyB

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I know enough to know that I don't know enough.

If the women don't find you handsome they should at least find you handy. Red Green

I did not reposition the drive dog, instead I repositioned the drive gear so the drive dog would fit in with the rotor pointed at about 2:00 at TDC.

I do not get any firing even though I’m seeing spark at the plugs and it did run just about a week ago before I changed the plug wires to the correct order and repositioned the drive gear.





Edited 1 time(s). Last edit at 2026-03-06 04:06 PM by dannyclarke58.

No one else here at the moment. Will tomorrow. Remote start switch is starting to sound like a good idea.

Still no start and not getting a consistent bright flash from the timing light when my wife cranks it over. Seems to suggest an issue with the Pertronix module.




Edited 1 time(s). Last edit at 2026-03-07 09:17 AM by dannyclarke58.

I've never had a problem with the three Pertronix units I have in operation. One in the '74MB and two in old tractors. 2 are the old Pertronix and one is the Pertronix Ignighter ll.

Might want to talk to the company.



Edited 1 time(s). Last edit at 2026-03-07 09:41 AM by MGBGM1977.

Do you happen to have a points distributor laying around?

No. Not do I have a points plate for the distributor since it had an original Pertronix ignitor in it when I bought it. It’s also one of the CA cars that had a CEI distributor.

Actually considering buying a cheap replacement distributor just to test with. 45D replacements are all over the web for under $100. Probably made in china but as I said cheap and would give me a baseline test.




Edited 3 time(s). Last edit at 2026-03-07 10:04 AM by dannyclarke58.

Confirm firing order 1-3-4-2 counterclockwise.

If the timing light is working the ignition is firing, may just not be at the correct ti me.

As mentioned, the engine can be roughly timed on the starter using the timing light, shoot for roughly 12 deg advance as a starting point.

Yup, 1-3-4-2 CCW starting top/front roughly 2:00.

Anyone have any idea why the pertronix can not be static timed?

Every distributor engine I have to start with a newly stabbed distributor, I set the engine to my desired timming mark on the balancer indicator, then with the ignition turned on and a spare spark plug attached to the #1 wire, I rotate the distributor until I see a spark jump the gap. I do it a few times to fine tune the accuracy. Why will this not work on the pertronix?

This is what I read somewhere:

Pertronix Ignitor II systems cannot be traditionally static timed because they require the engine to be spinning at a certain RPM for the sensor to accurately trigger the coil. Unlike points, which close a circuit to create a spark when opened, the Ignitor II uses magnetic sensors that need motion to generate a reliable signal.

Probably answered somewhere already, But, I'll ask anyway: with the #1 cyl at TDC on the compression stroke, where is the rotor pointing?

Roughly 1:30-2:00ish. Toward where the cyl 1 plug wire is attached.
*edited to correct fat thumb typing on my phone. �



Edited 1 time(s). Last edit at 2026-03-07 05:53 PM by dannyclarke58.