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tach signal, speedo problem

Posted: November 1st, 2013, 7:05 pm
by turbojeeper
ok to start off with my jeep is running on ms. i hooked up the tach signal wire to the negative on the coil and i am getting a tach reading but it is way off. tuner studios shows idle at 750-800 and it feels like that, but the tach says 1300 rpm. my rev limiter is set at 5300 and when i feel it hit the tach show 7000+ rpm. i know the pcm supplied the tach signal and i am wondering if i just nee to buy an aftermarket tach or what?

problem 2. the speedometer. i have 8 volts running to the sensor and the sensor grounded where the cluster is grounded (on block) with it hooked up i still get no mph but the weird thing is when i free rev or drive it the speedo jumps randomly with the rpm, but only when the speedo is hooked up. i already cleaned the crap off of the solder joints on the back of the cluster and at the connector, didnt change much. any ideas?

Re: tach signal, speedo problem

Posted: November 2nd, 2013, 9:53 pm
by vashxj
Is there anyway to find the wires for the crank signal and trans output signal and just tap into them right at the pcm

Re: tach signal, speedo problem

Posted: November 3rd, 2013, 9:59 am
by turbojeeper
There is no pcm anymore. Its on megasquirt now.so alk I have is the coil negative/signal from the squirt and speed sensor signal straight from the sensor

Re: tach signal, speedo problem

Posted: November 3rd, 2013, 6:33 pm
by turbojeeper
Well the speedo works again. Sensor wasn't tight in the tcase and had spun away from the gear.