Pertronix Ignitor

[TheEngineer]

Mikey is ahead of me here, but I'm looking at the Petronics Ignitor model 1864 LA. It's not that my car doesn't run, but perhaps this is a worthwile thing - and I could always keep the old points in the boot. My distributor (0 231 116 051) appears to have some wear because the dwell changes from 40º at idle to 34º at 3000 RPM. The promise is that the Ignitor module is less sensitive to wear.
Please, Guys, tell me your story! I also have a 0 231 185 009 distributor. It has an aluminum body and the vacuum retard is not adjustable and it is the replacement for the 051. It seems to me that Bosch has gone cheap with the 009

1969 280SL,Signal Red,007537, tired engineer, West-Seattle, WA

Admin: ignition electronic petronics

[erickmarciano]

great product for the 051 . you have to make shure you get the pickup whith the white dot on it <has a diff advance>.and you have to get the pertronix coil for 6 cyl ,you have to bypass the balast resistor and use carbon core sparkplug wires . good luck


1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[hands_aus]

I suggest that you do a search on this topic because it has been previously discussed in detail.

Also if you go to the Pertronix site you can read the 'trouble shooting' information. In there it will explain how to calculate the correct voltages needed and help you to decide how many ballast resistors you need. I don't think it is mandatory to change the coil.

I didn't replace the old coil on my 250sl or the wires which are recommended to be copper core with zero resistance.

Engineer, does your 280sl have the transistorised module under the battery tray?

The install on my car was simple and easy because the 250sl has standard old fashioned ignition.
I needed to adjust the timing and the air/fuel mixture after installation because the engine was back firing while driving.

Bob (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[n/a]

I've read most of the other posts about Pertronix and it seems that if you had a unit that didn't have the white dot on the magnetic ring earlier this year, those were the ones that had problems. After recently installing two of these units, I can safely say that you will not get a 1864 LA without the white dot.

One suggestion, although you would think that the white dot is an indication of something to be lined up with the rotor tip or other mark inside the distributor, it's not.  It's just an indication that you have the newer/improved unit.

Also, I rev both of my cars past 4,500 on a regular basis with no problems.

Mikey

[TheEngineer]

Yesterday I installed the Pertronix unit. It installed very easily. The engine started just fine and idles smoothly, but when I went for a test drive I found out that the engine misses over 3000 RPM. It's bad and not acceptable. So I put the points back in and went for another test. Engine runs just fine. I called Pertronix and so far have not resolved the problem. I have the 1.8 ohm coil and the 0.9 ohm resistor. My ignition is not transistorized. I used the 009 distributor, modified to give me 26° centrifugal advance. It also has 10° vacuum retard, set (with vacuum) at 3° ATDC. My total advance is 34° at 3000RPM. (Should be 30° per the book)


'69 280SL,Signal Red,007537,tired engineer, West-Seattle, WA

[hands_aus]

What model Pertronix unit did you install?

Did the circular magnet have the white dot on it that Mikey mentioned? Apparently the dwell angle was different in the units without the white dot.

Did you check the dwell angle with the Pertronix unit installed? Was it within specs for the distributor?

Did you calculate all the voltages in the trouble shooting guide to see if your system is within range?
Are the plug tops and leads NON resistive ones? Recommended total combined resistance of each plug top and lead is 1K Ohms.
Also is the air/ fuel mixture correct?

Bob (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[Naj ✝︎]

engineer,
Here's my 2 cents worth - but its probably negative, so maybe I should be paying!!
I installed a Pertronix system in my '68 280SL with 051 distributor last year.
I had the same problems as you. Misfire around 3000-3300 rpm. I was looking at changing to Crane but then I read about the later trigger with the white dot here and asked my supplier for one. Changing it almost cured the misfire but not completely.
I notice its there because I'm looking for it??
And I don't know what the fix is.
My belief is that the vacuum retard is there only to change the burn characteristics of the mixture to clean up emissions but does nothing for the performance or smooth running of the engine. To support this, note how much better the engine idles with the vacuum line disconnected!! Also, later 1970/71 280Sls have a valve arrangement to cut out the vacuum above 2400 rpm - why??
Anyway at the moment, I'm running the Pertronix with the vacuum line disconnected and the connection on the throttle body plugged up. And it runs good!!
Hope you'll find a fix and tell us all about it.
naj


65 230SL
68 280SL

[n/a]

I have a 71 with the transistorized ignition.  I never could get the pertronix to work correctly.  Bought their coil, talked to their troubleshooters, and waisted a lot of time and energy.  I finally sent it back for a refund.

The experience taught me to apprectiate the genious of MB engineering.  The more I read, the more I wanted to keep the original system.

Regards,
Don
71 280sl

[TheEngineer]

Today I received a magnet ring with the white dot on it. I couldn't resist to install it right away: The dwell becomes longer, it is now 20º at idle and decreases about 5º at 3000RPM. With the old magnet ring the dwell is 14º and also decreases by about 5º at speed. With points installed the dwell is 40º at idle and also decreases about 5º at speed. With points the engine runs just fine; with the new magnet ring - with the white dot - the engine begins to stutter at about 4000RPM. With the old magnet ring at about 3000 RPM. Tomorrow I'll put the points back in. It appears that the Pertronix does not provide enough dwell time to charge the coil. Must think about this some more.

[Tom]

I have used the Pertronix for 3 years now with several long trips of 1000+ miles-no issues.  I went to a hotter coil and bypassed all ballast resistors.

For late model 70/71 with emission controls, the RPM switch will not work (i.e. remove retard above 2400 rpm) unless you attach the green wire (I think green-that use to connect to the terminal block under the battery) to the negative coil terminal.

One item to note-the post from erickmarciano suggest that solid *carbon* spark plug wires should be used.  I think this should read solid *copper* wires.

1971 280sl Tunis Beige Metallic (restored & enhanced)
1971 280sl Tobacco Brown (low mileage stock)
1970 280sl Deep Red (Project Car)

[hands_aus]

I question that the 1864 LA Pertronix unit is the correct one for your 009 distributor.
It is correct for the 051. The dwell angle on my car (250 sl 051 dist) is consistently about 36 degrees (should be between 38-41)

My car does 3500 RPM AT 66MPH (110KMpH) and that is as fast as we are allowed to go. At that speed it just cruises beautifully and is willing to go faster.

I have pushed it to 70mph to go past a semi trailer but no faster. Still lots of pedal travel available though.

Bob (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[TheEngineer]

I'm giving up: I really tried hard to make the Pertronix work but I just couldn't get enoug dwell. The factory sent me a magnet ring with the white dot, it has thinner magnets and increased the dwell from 15° to 20°. That still was not enough to charge up the coil at more than 3500RPM. I did some bench testing: When the magnet passes the hall effect sensor, it opens the circuit (equivalent to opening points) and the coil fires. This open cycle lasts 40°. Then the magnet has passed and the circuit closes. That recharges the coil. It lasts for 20° for a total of 60°. Then it starts over. At the beginning of the open cycle you get the spark. If I could have reversed the switching to where the circuit was open 20° and closed 40° it would work. I returned the Pertronix Ignitor to the dealer. I rebuilt the 051 distribtor and I'm running it with points. I would have liked to convert the 009 distributor to an electronic ignition because I can't get points for it and the condenser costs over $30. Also, I reworked it to get a little more advance and the car runs very nice with it. Maybe I'll try Crane. For the time being, I'll go to sleep on the couch.

[hands_aus]

You did not say with which distributor you tried the new magnetic collar, 051 or the 009?
Did you eliminate the 5 degree variation when you rebuilt the 051 distributor?
Is that a picture of your installation shown on the post of 8th Nov or is it illustrative only?

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL, auto