Megajolt TPS wiring

[brainbug007]

I'm a bit confused about how the wiring for the tps goes with the MJ. My tps has 3 wires, blue, blue/black, yellow. The yellow wire is the center of the 3 and I'm guessing this is the signal input into the MJ on pin 10? Then according the diagrams, the ground wire on pin 9 gets sent to the tps. Does this become the positive into the tps so to speak and the vref coming from the tps becomes the negagive return from the tps? If so how does the MJ then get grounded back to the battery?

[davedew]

Vref is the +5v power supply to the TPS. The middle yellow wire is the TPS input to the megajolt. This value will increase with throttle opening.
The other wire connects to the same ground as the megajolt.

You have to get the outer wires connected the right way round. You should see an increasing value on the megajolt as you open the throttle. If you get a decreasing value the wires are the wrong way round.

Make sure you calibrate the TPS in the global settings and save the table it generates to the megajolt.

[brainbug007]

Ah cool thanks dave, confused me about the gnd. Would it work to just run a sepearte gnd wire from the tps to the chassis instead of putting a T junction in on the MJ gnd wire?

Yup once I get it work with my pc then I plan to have a good play with it and calibrate it. Did you build up your map yourself or use someone else's?

[davedew]

I got the MAP from DaddyA on this forum. I have got a couple to try though.

I connected mine in with the megajolt to ensure there was no chance of false readings screwing things up.

[brainbug007]

Fair enough. I've done all my connections with small bullet connectors so far. Would it be ok to have 2 wires going into one bullet? eg one that goes off to the tps for it's gnd and another that goes off to the chassis to be earthed and then the other end of the bullet just has a short wire that goes into the MJ?

[davedew]

Shouldn't be a problem so long as the connections are tight.

[brainbug007]

Nice one, those bullet connectors seem really good. Easy to install, small, & nice tight connection.

Just out of curiosity, how did you connect your computer to your MJ? Did you use one of those serial to usb cables?

[mark]

I got the MAP from DaddyA on this forum. I have got a couple to try though.

I connected mine in with the megajolt to ensure there was no chance of false readings screwing things up.

Thats the map from when i had a cvh in mine, was done on a rolling road unlike some you can find on the web, worked pretty well, for my engine anyway!

Should be perfect for brainbug as mine was a 1.8cvh and used the same bike carbs

[davedew]

I did buy the serial to USB adapter but my mums laptop has got a serial port in it so I had no connection problems at all.

Map seems to work well with my 1.6 but will see it needs a tweek when we get on the RR

[brainbug007]

Ya seems to be the only way to connect to the MJ is with an old pc with a serial port. I've ordered a cheap panasonic toughbook so hopefully that'll do the job.

My MJ did come with some maps, one of wich says Cvh with TPS so I'm hoping this will be good enough to start with.

[alga]

A mate of mine who works in the CCTV business says the only USB-serieal converter he trusts is Edgeport. A bit pricey, €74, but works every time according to him.