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no rpm registering on megajolt
Fishface - 23/6/12 at 06:31 PM

Im a bit new to megajolt and electronic ignition. Ive got my silvertop 1.8 zetec running on bike carbs a a mp kindly donated via this site. The car seemed to run ok at first start up but lately its been sounding a bit rough. I have two questions, firstly is the running. When its running and i blip the throttle it almost chokes to begin with and then clears at higher revs. I held my hand over each bike carb to see if they were sucking and somehow it seemed to clear it and the pickup got better? (Not starting it regularly enough perhaps?)

The second question is that the rpm gauge when the laptop is plugged in and the engine is running shows no rpm's at all, the tps works however. Any ideas?

Any help gratefully received


Slater - 23/6/12 at 07:56 PM

The MJ gets it's RPM info from the crank position sensor, which points at the back of the flywheel (on a silver top), the cable from the CPS must be sheilded along it's length. You also need to get the two wires from the CPS the correct way round for it to work properly.


Fishface - 23/6/12 at 09:17 PM

If I don't wouldn't that effect the running of it as well as not show up. That what confuses me as it seems to run ok


paulf - 23/6/12 at 09:29 PM

The RPM is picked up from the Edis PIP signal, if the megajolt is not receiving this then it will not control the advance and the ignition will be set at the default 10deg before tdc, the crank sensor is wired correctly if the engine runs .
It sounds to me as if you may not have the signal from the pip output on the Edis to the megajolt, either due to a faulty connection or less likely a faulty Edis module.Try and run the engine with a timing light attached and see if a mark on the crank pulley indicates the advance is working.
Paul

quote:
Originally posted by Fishface
If I don't wouldn't that effect the running of it as well as not show up. That what confuses me as it seems to run ok