Hi all,

This is my first post on Locost Builders and i have been pointed in this direction by the Tiger boys.

Ok so I have a Tiger Cat E1, Running a 2 litre silvertop zetec ford mondeo engine, Honda Fireblade bike carbs and a V3.0.0 Megajolt. So here is my issue. I took it to power engineering for a rolling road tune up but they could not talk to the MJ no matter what they tried. They gave it a power run and it came out at 126BHP

As the car was working fine but just down on power i still took it to the Track Day i had booked at Oulton Park, What a car ! amazing through the bends but got onto a straight and was noticebly slow

So after much tinkering about with my own laptop and speaking to the very nice guys at Chester motor sports I still could not get it to talk to my laptop, I kept getting "Time out reading runtime data" on the correct port for the Serial to USB lead to my Laptop. Ok i thought maybe something wrong with the MJ itself so i sent it back up to Chester motor sport, they tested it and it worked fine on there setup and was putting out 148BHP with thier map. ( I must add at this point that the MJ was not purchased from them, the guy who built it purchased it from the USA and then sent it to Chester motor sport for a map ).

So I had a very nice phone call from CMS saying that if i brought the car up to them they would more than likely be able to sort it all out only problem being they are 200 miles away

So does anyone have any ideas on what might be going on ?

I am torn between splashing out on a full new Weber alpha carb system for the car, or trying to get what i have working already !

Thanks for all the help in advance !

Frank3h

[Edited on 12/10/11 by Frank3h]

Lots of people have trouble with USB/Serial adapters, do you have access to an older desktop PC or laptop with a built in serial port that you could check the MJ with? You can power the MJ from a PP3 battery just for testing comms on a desktop PC.

If you put your location in your profile there may even be a forum member nearby that has a suitable PC.

[Edited on 12/10/11 by MikeRJ]

I dont think its the cable ( i could be wrong ) as it does recognise that there is something there on that comport ! but its doesn't get the info off the MJ ?

I'd try another USB/Serial adapter, Megajolt is notoriously sensitive to adapters especially with Vista, I have one with the Prolific chipset which works on xp, but not vista or win7, but I do keep an old laptop with a serial port for Jolt/Squirt use.

Where are you? someone local may have a laptop or working adapter you could try.

[Edited on 12/10/11 by r1_pete]

Sounds like a cable problem to me, there are lots of USB/Serial cables and there is only a few which seem to work with Megasquirt/MJ.

Hmmmm OK I am in Aylesbury

Will try Maplin for a new lead

I've had similar issues - cable is the most likely answer.

You need a computer with a RS232 serial port, i'm happy to help (im in Norwich) if you can get the car over here.

Alternatively, ask friendso or family members if they have an old computer lying about in the loft. Older PCs often have serial ports where as newer ones don't.

Also, i wouldn't pay to much attention to BHP readings from bench testing an MJ. More important is the carb jetting/needles, head, inlet, exhaust etc. The MJ only controls ignition advance, only one component of tuning the engine.

was 125 at the wheels or at the fly? at the fly that's about right.

I got my serial to USB adapter from Maplin. It works fine. Installed the drivers for the adapter and Megajolt shows up no problems. I would suggest its the cable connection OR the operating system doesn't support the drivers for the serial to USB adapter. There is a few threads on the MegaJolt Forums talking about these kind of problems.

first up there are 2 types of serial cable, straight through and crossover (or null modem cable) i think its the straight through you should have. so make sure what type it is! crossover cables are for connecting PC to PC, a pc will send on a particular pin, and receive on a different pin, if the PCs send pin isn't connect to the MJs receive pin, well....

go to the control panel device manager, and check which com port the USB works on, for the life of my i can't remember how though, think you have to have the usb/serial adapter plugged in (so plug it in and restart the computer for the best chance of finding it) back to device manager and open up the port (com&lpt) tab, you should see it in there i think, and it will tell you which com port it uses, then open up megajolt software, go to configurator optins, and change the com port to match whichever one shows on the device manager

[Edited on 12/10/11 by blakep82]

Thanks all i will keep trying

My problems with a serial adaptor have always been a com port mismatch, every time I plug it into the computer it moves to a different com port, the megajolt only reads up to com port 10.
So I go into devise manager and if the serial adaptor is on a com port higher than 10, delete some previous and fire it up again.