ive had this megajolt for several years now. i started having a missing/ misfire problem. it was from 2000 to about 4000, but now its from idle all the way up. the tach on the config jums around wildly between cells. with mj disconnected, it purrs fine in limp mode. looking for ideas here. i had a bad solder joint on d2. could i have overheated the component? i have followed all wiring directions including grounding to a T. its running a 1 lung motorcycle with map.
garthr
erratic tach display
Moderators: JeffC, rdoherty, stieg, brentp
It could be having problem reading the PIP signal, which the Megajolt uses to measure RPM.
You may want to check that connection for breaks, etc. Also, are you using shielded wire? Did you change spark plugs? The Megajolt + EDIS requires resistor type plugs to reduce electrical interference.
Failing that, if you have access to an oscilloscope you can monitor the signal going in to the Megajolt to make sure it looks like a clean square wave.
You may want to check that connection for breaks, etc. Also, are you using shielded wire? Did you change spark plugs? The Megajolt + EDIS requires resistor type plugs to reduce electrical interference.
Failing that, if you have access to an oscilloscope you can monitor the signal going in to the Megajolt to make sure it looks like a clean square wave.
i had changed plugs but im sure both were resistors but ill recheck. using shielde wire with the shield grounded. increased the pip filter thinking maybe it was some interference. checked the d2,d3, d4 diodes with a meter set for diode check. they had continuity one way with resistance and not the other and the stripes are oriented in the right direction. i may be able to use an ocilliscope. its automotive though and has an inductive p/u. ill let you know what i find. when this megajolt works, it works great.
garthr
garthr
i was unable to connect the scope i have. i changed the plug to a new one and verified it was resistor type but no change. i went thru the trouble shooting section and where it says there should be 12v on the pip line with ignition on and engine off, there is between 9-10v. battery is over 12v. maybe i should look for a short or bad connection on the pip route between mj and edis? any ideas? the tach jumps from zero to pegged not in any pattern or rythm. im sure running the engine this way is not good for it. still, if i pull the molex connector apart, and run in limp, the missing is completely gone. i checked to make sure the molex pins were inserted all the way into the connector. they were. i also reduced the pip shielding from 255 to zero with no change.
garthr
garthr
