Engine running hotter with 6A? Too retarded?

[Brit01]

MSD:

If it turns out to be bad timing with the 6A could it be a result of the extended wiring from the dizzy to the small red/white MSD wires I did?
I used about 60cms of extra wiring to reach the dizzy wires (all with good spade connections). A fraction of a delay could alter the timing as we know.

As I mentioned it starts fine and idles perfectly.

or even interference from the black/orange wires carrying 450 volts which are also extended and all tied together in a bundle?

[Brit01]

Well I disconnected the MSD and OMG what a difference in idling. Felt lumpy on stock ignition in comparison.

And traffic was too heavy and noisy to floor it and test for pinging. Did hear something so maybe it is my distributor that needs checking.

But the MSD certainly smoothes out the idling a lot.

[Brit01]

MSD:

When I re-connnected my stock ignition my tachometer was unstable at idling.
Flickering up and down between 800-1000 rpm.

With the MSD it was stable/smooth.

Could this be leading to an issue with the dizzy pick up?

Bosch Coil is new including the rotor and cap.

[LARRY70GS]

Just a thought. are you sure the polarity is correct on your magnetic pick up? The engine will run with reversed polarity, but it will run advanced.

[Brit01]

Originally Posted by LARRY70GS

Just a thought. are you sure the polarity is correct on your magnetic pick up? The engine will run with reversed polarity, but it will run advanced.

Pretty sure.

Negative wire from coil connected to small msd white wire.
Positive to msd small red.


Receiving other feedback that my mixture is just too lean on hard acceleration due to new oval K&N filters and short trumpets.

I will fit my original alfa airbox on and see the results (it has much longer trumpets at 90 degrees into a box with a K&N panel filter and cold air intake).

[LARRY70GS]

Originally Posted by Brit01

Pretty sure.

Negative wire from coil connected to small msd white wire.
Positive to msd small red.


Receiving other feedback that my mixture is just too lean on hard acceleration due to new oval K&N filters and short trumpets.

I will fit my original alfa airbox on and see the results (it has much longer trumpets at 90 degrees into a box with a K&N panel filter and cold air intake).

The white wire is used for point ignitions. You mentioned a magnetic pick up I thought. The magnetic pick up uses the green/violet wires. Also, the only wires connected to the coil should be the small black/orange ones.

[Brit01]

Ok further testing done.

1) original airbox on and stock ignition - smooth progression and no pinging
2) original airbox on and MSD running - hesitation between 2-3000 rpm and a small amount of pinging under fast acceleration. But smoother idling and more power despite the hesitation.

MSD have already told me more than once the 6A will cause a lean condition and is the most likely cause of the pinging.

So a slightly larger idle jet maybe needed?

[Gaz64]

What timing light are you using?

The light must trigger on the FIRST pulse of the multiple sparks.

Sounds like your timing light is triggering on the last pulse.

Which would then mean your real ignition timing will be more advanced than your timing light shows.

Extending your wiring as you have should have no effect.

I have yet to hear of ANY ignition system that causes a lean condition.

Less unburnt fuel from more complete combustion is the usual result.

[Brit01]

Timing light is a standard no frills one.
Timing reads the same on stock and on MSD set up.

Interesting find yesterday though. Stock NGK plug gap is 0.6mm for my alfa.
I opened the plugs up to 0.95mm and the symptoms began to disappear.
Also I had to make the idle mixture screws leaner, revealing it need less fuel to idle smootly and at the same rpm.

MSD recommend a gap of 1.25-1.5mm for standard compression engines which is a huge jump from stock 0.6mm for alfa romeo NGK.

So I guess playing around with the gap could be the resoultion here.
I will experiment with this.

Originally Posted by Gaz64

What timing light are you using?

The light must trigger on the FIRST pulse of the multiple sparks.

Sounds like your timing light is triggering on the last pulse.

Which would then mean your real ignition timing will be more advanced than your timing light shows.

Extending your wiring as you have should have no effect.

I have yet to hear of ANY ignition system that causes a lean condition.

Less unburnt fuel from more complete combustion is the usual result.

[Brit01]

Well that's interesting! My mechanic was right.

My picky boxer did respond differently to BP plugs instead of the standard B plugs.
Smoother idle, better response and the water temp was strangely 1/2 degrees cooler.
Didn't hear any detonation like before!!

Gap was set at 1.1mm with the MSD running.



All good so far