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Old 07-18-2011, 09:03 PM   #15
Bullet Ride
Cars in Perpetual Repair
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Join Date: Nov 2007
Location: Guelph
Posts: 6,000
Back from the dead....

Any MS guys here have any experience with the LM1815 VR Conditioner circuit?

Last year I had an issue with my DIYPNP where the car wouldn't rev past 2500rpm. I checked my tooth log and noticed some irregular noise and I was getting sync loss error code #2. I tried noise filtering to no avail. After speaking with Matt Cramer he recommended switching to the LM1815 circuit. However winter rolled around and the car got put away.

Fast forward to this year, I took the car out of storage a few weeks ago. It fired right up with no issues, still with the same problem as last year not being able to rev past 2500rpm. So I decided to try and switch over to the LM1815

Last year Matt had pointed me to this application document for an example of how to implement the circuit ( I wired the VR+ input on the connector board to the VR+ on the LM1815 circuit and the VR- input on the connector board to the VR- on the LM1815. Then I wired the LM1815 Out to Relay 3 In and Relay 3 Out to Opto+ and I installed the Opto ground jumper. I tried starting the car and now it's not getting a cranking signal so the car won't start.

Is this the way it's supposed to be wired? Was I supposed to keep the 18k resistor in series with the VR+ input (I removed it)? Do any changes need to be made in the TunerStudio Settings.

Any help advice would be greatly appreciated

Last edited by Bullet Ride; 07-18-2011 at 09:15 PM.
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