C3: Breakerless SE - no spark @ low RPM

[Dan Pepper]

I had the local speedshop rebuild/recurve a stock corvette distributor and install a brand new Breakerless SE. After the rebuild, he said that the distributor didn't appear to throw a spark until about 800 RPM. He said maybe it was a problem with his old SUN dist. machine, but hadn't seen the anomoly before. Said he's installed many Pertronix units, but they didn't have the same issue.

Ever heard of this before? If there is no spark under 800 rpm, how will the car start? Is there some problem with Sun machines and SE systems that cause this anomoly? Did he do something wrong when installing the unit?

[Joe L.]

Re: C3: Breakerless SE - no spark @ low RPM

Dan-----

I don't have an answer to this. It may be that the Breakerless unit that you have is defective. It's hard to believe that this could be an intentional design feature of the Breakerless unit. I mean, you're probably not going to achieve 800 rpm when you're initially cranking the engine and some engines even idle below 800 rpm. So, it just doesn't seem right, at all.

You might try contacting Dave Fiedler at TI Specialties. Dave has installed a lot of these units and I'm sure he's quite familar with their operational characteristics as well as previously encountered defects.

Let us all know what you find out, though.

http://www.tispecialty.com

[Jack H.]

Re: C3: Breakerless SE - no spark @ low RPM

The Breakerless SE has a few designed-in 'features' that may be confusing your mechanic. I suggest you install the distributor on the car and test it that way & only use the off-car/Sun Machine to diagnose/test the distributor with conventional Kettering points/condensor installed...

On the 'features', there are several:

(1) While the dynamic range of the single wire Breakerless SE is pretty darn wide, it DOES have limitations in terms of its ability to mfgr its on-board supply voltage from the single wire input. The mfgr has improved this over time (fight problems associated with cars sitting for LONG periods of time with battery discharging into oblivion, oxidized electrical contacts, Etc.) and the current version of the Breakerless will fire up & run with voltage input(s) as low as a 'titch' below 5 VDC.

(2) There's an on-board 'coil saver' feature. When you first key the ignition, the module checks itself and then goes to 'sleep' turning OFF the flow of current through the coil primary and upstream ballast resistor. The module's 'wake up call' is seeing a pulse train from the Hall effect trigger vanes (starter motor is turning the engine over). It takes something like five consecutive pulses for the module to percieve it's time to go to work and turn ON the flow of ignition primary current.

(3) The same works in reverse when you shut the engine down. The module goes into its 'sleep' mode when it preceives the absense of Hall effect trigger pulses (something like 15-consecutive absent pulses) and squelches the flow of primary current regardless of the ignition switch setting.

These 'features' are there to thwart overheating a classic cars ballast resistor & coil. Why let these hard to find original items 'cook' when the engine isn't running and the ignition switch is left ON?

Now, you can buy you Breakerless SE from the mfgr direct (M&H Fabricators) or from any of their authorized distributors (Lectric Limited is simply a distributor who repackages the module to make it look like they're the manufacturing source). I suspect the 'funnies' being seen on the Sun machine are the result of the way the module is hooked up and being driven/analyzed in that test environment.

BUT, there's no reason to guess. Give M&H a call, (562) 926-9552, and I think you'll find their technical support staff is fully manned, VERY polite/competent, and ready/willing to help regardless of where you purchased your M&H product from!

[Dan Pepper]

M&H = Class act

Jack- Just spoke to Tom @ M&H RE the problem. First I'd like to say I was VERY impressed with his knowledge and attitude towards support and service. They are a first class operation. Bottom line is that he's seen the same issue with older SUN machines - they have two in their facility. Although there is a very small chance the SE unit is defective, it's most likely fine. We'll see when I get around to installing this back in the car.

[Jack H.]

Re: M&H = Class act

Interesting that you got Tom on the phone...Tom Marquez is the CEO/owner of M&H and he DOES manage by 'walking around' and doing various jobs around the factory to keep his fingers on the pulse of the business. In my book, Tom and his company are a CLASS ACT which is kind of rare in this business!

That's how I met Tom the first time, over a product 'oops' issue. What SHOCKED me was, once Tom realized the problem was indeed his (no ducking behind a 'never seen that before' reply), he INSISTED on making remedy via Federal Express, Ovenight, at HIS expense. Heck, it was only a few dollar item and I even tried to talk him out of the excess rush/expense...but, NOOOOOOOOOO!!!!!!!

Happy to hear you got resolution, or are on a resolution track. It's what I expected from the folks at M&H...