Megajolt not responding to changes
Turbo Mini Forums

So I've had a megajolt in the Mini for about 10 years without issue. I fitted a hard cut rev limiter about a year ago and all went well. Recently I bought a new FTDI adaptor and got it talking to the new laptop. I tried to change my rev limiter and shift light setting but noticed the limiter wasn't working. Then the laptop disconnected the ECU and I got a pop up say there was an issue with the device. It intermittently comunicates but I can't change the settings and I noticed the rev and map gauges move but the configurator doesn't move with revs. Now the shift light comes on at idle, and the rev limiter comes on at about 2000 rpm when it is set at 6000 on the software. Sometimes the limiter doesn't work so it drives ok but I think it's running off the edis only when it does this. I noticed some oily fuel residue in the MAP line and saw it has leaked onto the PCBs.

Sooo... the wiring is ok, the ECU gets power and is earthed but I suspect it's runing off the edis only most of the time. If the configurator isn't responding to rpm but the rpm gauge is I take it the VR sensor is OK but it's an issue between the megajolt and edis? Is it possible the megajolt or rev limiter PCBs are damaged? I was going to buy a new megajolt as mine is old but I don't want to if it isn't the issue. But since its communicating with the laptop only sometimes, the laptop detected an issue with the ECU and it's not changing the timing according to rpm I suspecting it is?

Thanks lads!

Go back to old laptop and old adaptor that you know works 100%

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

And confirm if timing is behaving as it should with a timing light etc.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Poxy converters, it's probably set to the wrong baud rate if it's intermittent.

if its a windows xp laptop that hasnt been updated in a while, you could have "bricked" your ftdi cable. ftdi rolled out drovers to brick clones of there chips, after backlash the drivers rename the usb Identification to all 0's but the end results the same the clone chips wont work under windows.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Ah ok, I will check out the settings then and assume it's still a cable adapter thing. I suppose that makes sense if it's a bit hit and miss. I got the driver off the internet and I'm using it with windows 10, does anyone have a driver that works with this setup?

If it's got the genuine FTDI chipset in the adapter, W10 should have automatically updated the drivers as soon as you plugged the USB end in (provided you had/have an internet connection).

That is what happened on both my laptops when I upgraded from W7 to W10, as soon as I plugged the cable in it just brought up the little window asking my permission to update/install the drivers for W10.

See this document
http://www.ftdichip.com/Support/Documents/...indows%2010.pdf
There is a link in there for the drivers if the auto update thing doesn't work.

I think Denis's point is that they have taken steps to stop some of the clones from working.

Schrödinger's cat - so which one am I ???

yeah sorry that should have been xp or newer, the clones are pretty prolific and this has caused a lot of problems as even companies who thought they had purchased a genuine FTDI product had in fact bought batches of clones.

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

I bought it from trigger wheels so made the assumption it was genuine, it definitely didn't work without a driver download. I will look for my old lead, it was a cheaply and worked with an older windows version but I don't think it worked with windows 10. Apart from not being able to connect with the megajolt and not being sure about the ignition timing, the mini drives well.

I had another look at it today and thanks to everyones input I got a bit further on with it. I uninstalled the driver and let windows install everything, it comunicates well now. But I did notice the rpm on the gauge doesn't match the configurator:



The gauge is at 1700rpm but the configurator is in the 800 rpm bin. Obviously I changed the bins to check this, this isn't my usual map.

Is it an rpm input thing?

Does anyone have any ideas why the configurator table and rpm gauge on the software shows different readings? It's about half, that seems to be why I'm not getting the right timing. I take it the rpm gauge gets its signal straight from the crank sensor but the configurator table is via edis?

Does it think you have an 8 cylinder in there?
I don't know where you would check that though. A setting somewhere

It's in the tools menu, under global controller options, or something like that. It does sound like it's set to 8 cylinder.

Yeah you can change that under tools, I did look as this previously but I'll check that I have set it back to 4 cylinder. I'm thinking I might have damaged the rev limiter chip, and its only sending out half the pulses but because it's waisted spark it still works?

I'm getting a timeout error when I save a map to the ECU, then if I try and access the map on the ECU I get this:



Amy ideas? I might start from scratch with a new magajolt.

Or go back to an old laptop that works

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will