Megajolt Tps won't map

spud69 · Post by **spud69** » Mon Mar 23, 2009 11:07 am

Just a quick question:

Got megajolt all up and running on a 2.0l zetec with bike carbs except the tps on the ignition map is not traveling the full scale only from 10 to 20% throttle. The rpm is advancing fine. I've calibrated the tps and it works fine on the analogue readout on the software moving smoothly from 0 to 100% throttle. Anybody had this problem before?

Cheers..Andy

MartinM · Post by **MartinM** » Mon Mar 23, 2009 11:05 pm

What values do you have next to the rows on the map? 0 to 100 or something like 10 to 250? If the latter then you need to change them to 0 to 100 to reflect the calibrated TPS....

spud69 · Post by **spud69** » Tue Mar 24, 2009 8:26 am

Thanks Martin but i've tried it with both values in i just cant get it to map the engine load even though the load is working fine on the analogue gauge. When i change the load bins from 0 to 100 the cursor moves from 0 load to 10 load at about 20% throttle opening.

Cheers...Andy

hammy · Post by **hammy** » Wed Apr 08, 2009 4:27 pm

I have a similar problem -only worse. I've calibrated my TPS and the load meter moves in response to the throttle pedal but I get no movement at all in the load axis of the map -the dial goes around but the map stays firmly on the top line.

MJ is advancing the igntion as measured with a timing light -but only along the rpm axis.

I intend to try reloading the software later in the week to attempt a cure.

[I used the tps calibration software, my map goes from 90 to 230 -I assumed (rightly?) calibration procedure sets these values to correcpsond with 0% and 100% ??].

I'm on V3.2 I think ?

MartinM · Post by **MartinM** » Wed Apr 08, 2009 9:16 pm

hammy wrote: [I used the tps calibration software, my map goes from 90 to 230 -I assumed (rightly?) calibration procedure sets these values to correcpsond with 0% and 100% ??].

I'm on V3.2 I think ?

'fraid not....

... it's all designed to be easy to use and so when you calibrate the TPS you need to adjust your map load rows to be from 0 to 100, corresponding to 0% to 100% throttle.

By having your top row at 90 (%) then it's probably not surprising that your map spends most of it's time on it.

Try adjusting the map rows to be from 0 to 100 (every 10 for example!), see how you get on and report back...

Martin
PS ...and if you switch the Configurator to display TPS% on the load gauge, then with a calibrated TPS that should go from 0% to 100% also...

Dave R · Post by **Dave R** » Wed Apr 29, 2009 5:04 pm

I've just fitted a Megajolt V4 to my Frogeye Sprite and am having exactly the same symptoms as Spud69. I was so pleased that my 'micro soldering' actually worked and now I have this issue. I've tried changing the bins from 1-100, 0-255 & 0-10 and recalibrating the TPS. They all give 0 to 100% on the dial gauge and logger but also all only go between row 1 and row 2 on the TPS bins.
Help on this one would be gratefull received.
Dave

Post by **brentp** » Wed Apr 29, 2009 6:45 pm

Hi Dave,

Once you've adjusted your bins - say, from 0 to 100% in 10% increments- make sure you write the data to the controller and then 'flash' the configuration. Double check this and let us know what you find out.

Regards,

Dave R · Post by **Dave R** » Wed Apr 29, 2009 9:46 pm

Hi Brent,
I started with 0-100 bins and got this effect. However, I'll re-set it again tomorrow and report back.
I got a bit confused about the meaning of the bin numbers. I'd assumed that it was 0 to 100% (in 10% increments), but when that didn't work I 'logiced it out' (is that english??) that the bin numbering must be 0 to 255 ADC values. The fact that I don't know what an ADC is didn't stop me! The illustration in the hen got confused by the Operation Guide seemed to confirm this view. I then got confused by the non-linearity of the bin numbering which did not appear logical.

You are right.........I get confused quite easily. Still, I have confidence that you and the Community can did me out of this hole. You succeeded when I confused myself over rev limiter issues with my first Megajolt.

I'll be back tomorrow.
Dave

Dave R · Post by **Dave R** » Thu Apr 30, 2009 6:18 pm

Hi, I've done what you said, with no change to the result; I still only get bin 1 and 2 selected on the load axis for nil and full throttle respectively.

The only odd thing that I've noticed is that the icons that 'write' and 'flash' to memory are not illuminated when I come out of the Load Axis Calibration window. I assumed that by pressing the 'Write Calibration' button within that window it would write and flash to memory. The write and flash icons only seem to illuminate if I change something.

I'm running out of ideas so anything is most welcome.

Regards,

Dave

Post by **brentp** » Thu Apr 30, 2009 6:42 pm

Hi Dave,

The Load Axis calibration procedure writes the data directly to the controller flash memory- It's not part of the main "ignition configuration" data.

The write/flash buttons on the toolbar will enable if you change something in the main ignition configuration- such as the ignition map, Load/RPM bins, and user-defined outputs. So, if you change the bins, you need to 'write' it to the controller by pressing the 'write ignition configuration' toolbar button.

Can you attach a copy of your ignition configuration (.mjlj file) to this thread? be sure to save it after reading it fresh from the controller- i.e. after a controller power cycle.

Thanks,

Dave R · Post by **Dave R** » Fri May 01, 2009 9:53 am

Hi Brent,
I've downloaded the .mjlj file as requested. I hope that I've understood your term 'power cycle'. I turned on the laptop, connected it to the Megajolt then turned on the car's ignition. I then pressed the 'read' icon and saved the file to the laptop. I trust this is OK. I've added the throttle calibration file for completeness (assuming that I can attach it to this posting).

Many thanks,

Dave

MartinM · Post by **MartinM** » Fri May 01, 2009 7:36 pm

Attachments work fine - and so do the map and the throttle calibration on a test MJLJ unit.

Which is sort of

and

at the same time really.

Can you measure the voltage coming from the TPS whilst moving the pedal - pin 10, to the left of the Ground pin - on the MJLJ plug?

Report back....

Dave R · Post by **Dave R** » Sat May 02, 2009 10:31 am

Hi, I inserted a dummy plug / socket in the cable from the TPS and left the linking wires exposed so I could measure the volts relative to ground. This is what I got:-
Throttle closed: Yellow; 4.96v, Green; 0v, Red 1.07v
Throttle full open : Yellow; 4.92v, Green; 0v, Red 4.77v
I guess green is earth and yellow the supply voltage

In addition I swapped the MJLJ for the second box that I soldered up. I was starting to assume that my soldering had burnt out a conponent on the TPS circuit (I can admit that my soldering is less than perfect!!). However, the second MJLJ not only worked, it also exhibited the identical characteristics as the first unit. ie All RPM bins are 'active' but only lines 1 & 2 on the load axis 'light up'.

I hope this is useful info in seeking out the solution.

Regards,

Dave

MartinM · Post by **MartinM** » Sun May 03, 2009 8:30 am

That all seems fine. It's not crystal clear, but are those voltages with everything in place as normal - you can get a narrow multimeter probe in the back of the Molex connector. So can you be explicit about what the voltages are with respect to ground on:
- pin 2 (Vref, next to +12v in)
- pin 10 (TPS, next to GND in)

Off the wall thought - you have got the TPS ground connected to the MJLJ ground connected to the vehicle ground? I've seen people miss off the latter- weird things then happen...

Strange that a second unit does it as well - common build error?

Dave R · Post by **Dave R** » Sun May 03, 2009 5:40 pm

The voltage readings from the Molex pins (when connected to the MJLJ and powered up) are the same as my last email. I've attached a sketch of my wiring just in case there's an obvious error. I've checked the wiring at the Molex to see if I've swapped any wires round but they all appear in the right place.
The ground connections are as shown in the sketch and go to an earth terminal block near the battery earth where they meet the EDIS earth.
There could be a common assambly mistake with the two MJLJ boxes but that's unlikely, my rubbish soldering is more erratic than that!

I feel that I'm not much further forward with this one. I wonder if Spud69 or others with this characteristic have found a solution?

Anyway, your help is greatfully received and I happy to keep trying things until your patience or ideas dry up!

Regards,

Dave

Autosport Labs