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1979 930 @outlaw3.4
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A 'UNIGUE "MSD RPM Switch Issue
I recently added the MSD RPM switch. It is installed as perinstructions and the solenoid is energized with switch power. The solidoid is opening as dictated by the MSD pill rather accurately..however it immediately closes as if the RPM signal was cut to the MSD box.
I am taking the RPM signal to the MSD box from the black / violet wirein the sixpin harness. I do have dual CDI box and a good RPM siganl at the TACH. I have solid voltage. I know fir fact the Adj WUR is working without the MSD switch under boost and holding enrichment pressure while under boost. Once Ihave the MSD energized the signal gets to the WUR, but then withing few 100 RPMs under WOT /Boost it immediately goesback to Control Pressure. The AFR follows the control pressure so I know its a good reading. Without the MSD I see the usual massive fuel dump as boost hits the threshold pressure setting and CP drops to EP and holds....and as everyonehas experiencedIgetthe lean tail as boost and RPM climb above 4k toward 5k. with the MSD ...I have good AFR through 4k...( or where the pill dictates) and then a drop to EP andgood AFRs for a bit ...then back to CP and the lean curve appears..... I amgoing to try to take an RPM signal off thesafeguard unit which is currenlty driving the RPM signal on the INNOVATE gauge. Most of the threads with MSD switch I read are using MSD or some other than OE 6pin CDI ignition. I heard I should "SCOPE" the RPM wire...but thats way over my ability at the moment. I tested the solenoid and the fail and default is open....which would allow the boost signal and EP to stay under boost....so it must be shutting off. Anyone experience anything like this ?
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1979 930 3.4l Peter Dawe Motor, Bosch Twin Plug, Dual Bosch CDI, J&S Ignition Control, Webcam 158 , Maxed Flowtech Fuel Head, BL Adj WUR, Braided Fuel Lines, 009 Injectors, GT35R, TIAL .7with Turbosmart MBC, Fabspeed Long Neck IC, Fabspeed Headers, GT3 Style Pipe off turbo, Rennshift Short Shift, KEP Clutch Package, 8.41, Elephant Racing Suspension, Weltmeister Sway Bars, ??WHP, Innovate MTS Gauges, RPM, Switch,SplitSecondAIC 7th |
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