MSD 6A on Alfa romeo 33

[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.

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 distributor pick up?

Bosch Coil is new including the rotor and cap.

[Brit01]

MSD SS Blaster Coil has arrived finally.

Has a primary resistance of 0.8 ohms and is E-core technology. My Bosch stock coil is 1.5 ohms.
This should make the spark stronger I believe and E-core has a faster discharge.

Let's see how it compares.

Original airbox is going back on this weekend if I have time. That will restore the cold air intake for the carbs.

Chris

[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.

[Brit01]

Well that was interesting.

I changed to colder plugs and widened the gap to almost 1mm.
I had to lean out the idle mixture screws and a fast spin around the block felt much better.

Maybe just the gap needs fiddling with as the spark is much stronger.

[idv]

Hi
It sounds like you need to try resistive spark plugs.
In the early days they used to use resistive caps but now it is easy enouge to by spark plugs with a resistance built in.
These are really good for getting rid of electronic interference but also the resistance slows the burn time of the spark, similar to openning the gap wide, they really are a must with electronic ignitions.
Have a look at the NGK cataloge online, there are resistive equivalents for almost all plugs.

[Brit01]

Hi
It sounds like you need to try resistive spark plugs.
In the early days they used to use resistive caps but now it is easy enouge to by spark plugs with a resistance built in.
These are really good for getting rid of electronic interference but also the resistance slows the burn time of the spark, similar to openning the gap wide, they really are a must with electronic ignitions.
Have a look at the NGK cataloge online, there are resistive equivalents for almost all plugs.

Do you think the interference caused by using the the non-R plugs could be affecting the trigger signal?

[idv]

Hi
I don't really know. But the technitians that I know, who convert older cars to EFI with electronic ignition, automatically change the plugs to Resistive ones.
I have seen really weird faults corrected with resistive plugs, as if it were magic. And it was completely repeatable.
I'm not saying it will fix your problem, but for all the effort you have put in, it would be a shame to see you give up without first trying them.

Another issue, is that with the higher output coils tracking or arcing in older components can be a problem. The increase in voltage may be just enough to cause arcing, usually the distributor cap or rotor, and the only way to find out is to replace with brand new ones.
I have converted a 2l Lancia to coil-overs succesfully, but I tried all sorts of combinations as experiments and it is amazing what works. The two most valuable lessens I learnt were, use new components and use resistive plugs.
I do hope you have some success with this.
Ian.

[Brit01]

Cap and rotor is new. No signs or symptoms of arching.

Well the Alfa is in the workshop now, I hope in good hands.

He has to check an issue with the right hand suspension first then will check the timing, distributor, plugs etc.

Maybe he'll even take the distributor to have it tested on one of those testing benches for the curve if we can't resolve the advance.

[Brit01]

Nothing wrong found with the distributor or system yet. Timing was perfect.

He said to try the 'P' plugs as this should improve the burning and help to avoid detonation.

Well just got the plugs and will try them out.
BP8ES.

We had a discussion about the R type plugs and decided to try the P plugs first as they weren't convinced that the resistor will do anything towards the detonation. Just possibly take away some of the MSD power.
Well plugs are cheap here so we can try them later if the P plugs don't make any difference.

Collecting the car tomorrow morning.

[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.

:)

I want to try my EMPI oval filters again to compare.

[Brit01]

These are my BP8ES plugs after a motorway run of 100kms with the MSD running. Detonation still evident (with or without MSD). Suspecting distributor advance curve now and will get it tested.
Averaged about 90kms, so just running on idles mostly (55 idles).
gap 1.1mm

Looking ok or a little hot?

No brown on the ceramic part which I expected being on the colder side of plugs.

The MSD does give a good strong spark. And this is an older version which had a little less energy than the newer 6A's.

[Brit01]

I hope someone can let me know if these plugs look ok or maybe I need a step colder for motorway driving.

Thanks,

Chris

[Urbancamo]

Chris

With modern fuels, even the ones you have in Uruguay, the combustion is very clean and it leaves very little residue. Plug colorong can take for a very long time, 2000-5000 kms in some cases.
I just changed the plugs for a Volvo 5-pot engine wich had them for 75 000 kms. They very clean even in this much kilometres behind.
With modern fuels you really cannot read much.

But look two things; the porcelain for obvious black or shiny particles (there should be pretty much anything) and side strap for color change. Ideally color should change in the apex of side strap. You can find more info in the web, there are plenty of knowledge available how to read critical things.

[Brit01]

Thanks.

I read that if the ground strap colour changes too close to the ground strap's end, (located above the center electrode), then the heat range is "too cold", meaning that the strap is loosing heat too quickly to the base ring. It is not able to burn off deposits until near its end.

If the "colour" of the strap changes near where it is welded/attached to the base ring (last thread ring), then the plug heat-range is "too hot", because heat is not being transferred or cooled from the strap to the base ring quickly enough. The strap might begin to act like a "glow-plug". Eventually causing pre-ignition and/or detonation later on. The proper heat range is when the "colour" is at the half-way point on the strap. This means the plug is neither too cold or too hot.

The air/fuel mixture ratio shows up on the base ring. This is the last thread ring, it has the strap welded to it. You want a full turn of light soot colour on the base ring!!! If you want to tune for maximum power, then you want 3/4 to 7/8ths of a full turn of light soot colour to show up on the base ring. This is on ragged-edge of being too lean, but will make the most HP in most engines. To be safe, leave it at a full turn of light soot colour. If the base ring has a full turn of coluor, but there are "spots" of heavy build-up of "dry soot" on top of colour, then jetting is too rich.

I will look closely at the plugs again.

[Brit01]

MSD failed!

Worst possible place in traffic on a filter road in front of traffic lights with a line of cars behind me.

Haven't had time to check it yet but I'm suspecting the Blaster SS coil. It was hot to touch and there was a burning smell.

Quick swap back to original ignition and was off on my journey again after 30 seconds.

Will take out the coil and measure it's resistance and also check the 6A for a spark.

I have to mention the blaster coil says on the MSD packet 'Made in China'!

Maybe if the 6A is fine I'm better off using my Bosch coil with it (or sell it!). I'll see.