Runtime display shows that timing is not changing for differ

[goldminijohn]

Hi everyone,

When I look at the runtime display for my megajolt unit I have found that the system is not jumping across the different advances for varying manifold pressures. The advance moves across the top line [100 kpa in my case] and goes to different sections for varying revs but the system isn't going up and down the map for different manifold pressures although different manifold pressures are displayed. Is this likely to be a problem with my megajolt unit or just my computer and its software getting confused?

Thanks

John

[rmaddock]

I noticed something similar with mjtuner but I was just testing the box on my dining table so I didn't think much about it. Sucking on the map tube registered on the bar graph display but the advance table never responded.

[MartinM]

The highlighted box on the runtime display should definitely move up and down as well as side to side!

Home-made or Brent-made?

What range of manifold pressures are displayed? Is the displayed range enough to jump up/down the map values? If you disconnect the pipe to the manifold and suck on it with the engine running, does the box move up/down the map?

I don't know if it makes any difference, but I always have the map with low pressures eg 20 kPa and low revs eg 800 rpm at the top left of corner ie revs increase and pressure increases as you move across left to right and down.

[goldminijohn]

Hi again,

The megajolt unit is homemade but with chip pre-programmed by Brent, the system has previously moved around the map as expected. The pressures ranged from about 100 to 50 so should definately have moved. Is it likely that the firmware for the chip has got corrupted? My laptop is pretty old and slow so it may be related to this but as I said, the system has worked fine previously.

Thanks,

John
ps. I wouldn't worry if the position didn't change when testing, I think it will only start changing once the system starts recieving signals from the trigger wheel.

[rmaddock]

Mine's Brent made, and I altered the map so that sucking on the pipe should deffinitely move the box. But as mentioned, mine wasn't in the car so no RPM input.

[goldminijohn]

Just an update,
I swapped the map round so that lowest pressure and revs are at top left corner and now the system seems to be stepping through the points fine. Thanks for the suggestion. I was fairly sure that the map had worked the other way round before but maybe I just saw that it was moving and didn't think about it moving around the map.

Cheers,
John