How can you *calibrate* this guage? It draws its reading from a completely different place in the engine than the one the PCM does.

 

I'm, with Rob.... I ran an MSD-6A on my car almost from the day I bought it. The Opti started to show signs of problems at 50K miles. I removed it, and the cap/rotor section was in absolutely perfect condition, no signs of wear, like new. It was rust from the cheap carbon steel bearing retainer that had started to blind the optical sensor, and set DTC 16. The bearing was also showing signs of distress. The unit was getting hard to turn. I don't see how any of these problems would relate to what is going on in the high voltage section, except possibly increased ozone generation.

There are numerous causes for the failures, most of them related to poor case sealing and poor selection of components. I personally would not attribute the failures to "multiple spark" ignitions, at least not based on my experience.

 

This is all very interesting. I am glad to hear everything. The one reason I mentioned the Multiple Spark ingnition was based on an old obervation I had with the Cap of an old car.

What I noticed is that the contact would begin to develop a white rust on top of an eroded area of the plug contacts on the cap... The replacement cap I used had aluminum contacts... I also observed on my Ex G/f car that her cap rotor was not wearing out at all... not the contacts that is... It was from a Honda civic and the contact were made out of Copper.


My thoughts were that the continuos sparks jumping from the rotor were wearing out the the cap contacts.

Now I have not seen the OPti cap rotor insides but I did wonder if the multiple sparking could, to a some degree speed up the wear and tear of the contacts...

I am glad about all your responses... very interesting material.. thank you all for your replys.

Marvin

 

The head... Using the Ohms Law to calculate a resistor in series or a voltage devider.

Using a potentiometer saves the calculations. all we need to do is to change the Gage Temp sensor output. You right it is a diff sensor and thats the beuty of it.

No need to touch the coolant temp sensor at all. Temp sensors are Thermistors with a given resistance to electricity that changes with Temp. the Resistance goes down as the sensor gets hot... well all we need to do is ad a resistor in series to the wire output of the sensor. The value can be found using a potentiometer.

I will work on it when I am done with my own fan mod. I will post it when I am done. should not be dificult....


Marvin

 

I think on the average, optis are lasting as long and longer than the regular distributor, cap and rotor.

I'm still on my stock one, even with the WP having been replaced in the past, and I'm over 111K miles.

I imagine that it's the time and annoyance involved in R&R that makes it stand out more.

 

Good point. it was so much easier to swap a 12 Dollar Cap from the Autopars using one screw driver and some elbo grease. Also I dont think I have ever owned a car with a reg distribuitor that had the Cap and rotor lasted me up to 140k miles on it.


My opti has now over 140k miles on it and I am actually specting to replace it very soon. there is a tread about AutoZone Optis that gives me a head ache each time i read it but I keep going back to see if anyone finds later on when and who will be the first one to include the electronics/cap/rotor all into one package at a lower price than the Dealer. I hope my Opty last that long too...

Marvin

 

i dont have an aftermarket ignition but i do have 230,000 miles on the stock opti! i too had to replace a leaking waterpump, im surprised that it didnt wipe it out then.

that has to be the record for most miles on stock opti. or close to it!

 

Well, I just replaced my Opti, and it wasn't the problem. So, it was still going strong after 100,000 miles.