JBrown

My mechanic though he heard that brian leasks WUR solinoid set up would not work with Crank fire ignition. Is that true. I have his WUR in the car now and running rich in midrange and was going to install the solinoid set up.
Thanks John

LeonardZ

It only needs an RPM signal. What does your tach run off of ?

Leonard

sand_man

I have Electromotive XDI ignition in mine (crank fired) and Brian's RPM solenoid. I spliced into the tach line from my Electromotive controller and whenever I put the turn signals on, step on the brakes, turn on the lights, my tach needle bounces all over the place....like I'm getting some sort of electrical interference. I checked for good grounds and power source, all is good.

The switch itself appears to be working fine (no irregularities on AFRs that I can see). I just think I either need to splice into a different part of the tach wiring or try out the the number 21 pin (advance output) on my XDi unit. I'll verify if this voltage from this pin is sufficient for driving a tach signal by running a few tests. I plan to play with it this weekend.

sand_man

BTW, I had no tach problems before installing the switch.

sand_man

Can your mechanic elaborate...I'm curious...

911rudy

Have you tried a diode inline with the trigger?

JBrown

I tapped into my blk/violet tach wire. It all works fine, except my tach jumps once in awhile too. Does anyone know how to fix this? Thanks John. 911rudy are you saying to diode isolate the wire so nothing feeds back into the tach for the solinoid tach wire?

sand_man

I wonder what value diode would be suitable? How and where to attach it? I still plan to see if pin 21 coming out of the XDi controller would work.

sand_man

From MSD, there is something called a "Tach Splitter". Part number 8911... I wonder if this would help prevent the feedback?
http://www.msdignition.com/media/images/8911.jpg

sand_man

Edit: keep in mind that Jbrown and I no longer have a dizzy...

JBrown

sand-man you are thinking of a resistor with values. A diode only lets a + or a - signal go one way. They are measured in amps.

sand_man

Yep, you're right....that's what I was thinking of. So edumucate me on where I find a diode and how to install one.

JBrown

sand_man, you can get diodes at radio shack. I dont think that will help . It might cause resistence in the signal. I am going to email Brian leask and see what he recommends.

sand_man

What I'm stumped on is how simple the wiring is for this solenoid, yet how trying to splice into the tach wiring causes the tach needle (in the car) to go crazy whenever another elctrical source (headlights, brake lights, turn signals, etc.) is engaged. Just driving the car around with no other elctrical source running, the tach is fine.

How is it picking up the feedback and/or interference?

911rudy

It sounds like the new wire has opened another leg for the entire circuit to follow under some circumstances. Take the amp data that comes with solenoid and go to Radio Shack and tell them what you are trying to do. The diode simply creats a oneway gate so that leg can't become an alternate path or allow any interference back through the tach circuit. It may not work but a pack of four diodes is not much.