Switching Maps???

General Topics for configuring, operating and tuning the Megajolt. Also see the <a href="http://www.autosportlabs.net/MJLJ_V4_Operation_Guide">Operation Guide</a>

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910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Switching Maps???

Post by 910esprit »

Has anyone had an issue with the maps changing on its own.
I noticed the other day that i was not getting full boost (output 2 controls a valve that bleeds boost to the capsule), when i checked the output that drives an indicator LED to show what map is being used, i noticed it was flickering rapidly, this appeared to be vibration related, i switched to map 1 and everything which does not have an indicator light so i am not sure if it was still doing it, after the run i left the car for a couple of hours and when i started again the same thing was happening, I drove about 50 miles then switched back to MAP 2 and everything was fine!!
I checked all the connections and everything seams ok.
This weekend i went on a long trip 200 miles and guess what, it happened again... on the return trip i kept checking map 2 and the light was flikering, but it appeared to be more like engine related, I.e if i declutched and rolled the light became more stable, and if i blipped the throttle it would flicker more. Then after a 70-90 hard exceleration run i got a misfire, just the one, so i backed off, After that every time i put load on i got a misfire even in map one. so i limped home waiting for the breakdown but managed to get home.
After a cup of coffee, i restarted and every thing was fine!!!
Has any one experience engine interferance? or Maps switching on its own?
I have connected the option switch using a 12v from the TPS (i am using MAP) using a 1Kohm resistor which is then switched to earth for map1.

910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Post by 910esprit »

Ok further developments, i am now getting a regular misfire, but there does not seem to be a pattern to it.
I think it appears more under load but cant be sure.
the rev counter drops when the misfire happens, this is driven from the EDIS not the MJLT.
I have replaced the EDIS module and still get the same symptoms, i have also disabled the second map switching option but no improvement.
I cant at the moment disconnect the MJLT as the coil goes through the hard rev limiter in the MJLT and depowering it depowers the coil.
The next step is to rewire the lot and connect it back up so that i can run the EDIS module at 10degree and see if is still get the misfire.
Any one have any further ideas??????

DannyP
Posts: 417
Joined: Sun Apr 09, 2006 3:48 pm

Post by DannyP »

Seriously check your VR sensor and mount. Possible EDIS module or even a coil. I would check the whole harness, and bypass the rev limiter temporarily.

910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Post by 910esprit »

Thanks for the reply,
I have now replaced the coil pack but can't test until tomorrow.
If this does not work then i will get the car in the air on the weekend and check the VR sensor and mount.

910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Post by 910esprit »

OK replaced coil pack and still get intermittant mis fire.

I will have to have a look at the VR sensor on the weekend.... I am pretty sure that i have a problem with the MJLT.

I have reverted to origional ignition to test and car runs fine (not as good but there is no misfire..)

Anyone upgraded to a ver 4 thats got a ver 3 for sale, need to test this out as i am running out of ideas.....

brentp
Site Admin
Posts: 6275
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Hi,


Although your disabling of the map switching option didn't seem to have an effect, you can still try an alternate way of driving that input: Try to re-wire the option input pull-up to +5v internally using a 1K resistor, instead of the 12v feed. Your map switch would still pull the option line to ground as before.

More importantly- you should *definitely* try to run the system on EDIS by itself, with the rev limiter bypassed. Should be a fairly quick test and helpful test.

Try both of these ideas, and see how it works.

Brent
Brent Picasso
CEO and Founder, Autosport Labs
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910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Post by 910esprit »

Update:
Removed rev limiter, still got mis fire.....
Rewired so that EDIS can run on its own, All seemed ok but after hard excelleration mise fire on the overrun... then the occasional mise fire under load....
Reconnected MJLT all seemed ok for a while, then after hard excelleration misfire on overrun as i lifted off...Hmmm.
Checked the VR sensor mount and sensor quickly and all is secure.. I am now thinking that the VR sensor may be too far away from the sensor wheel but cant check at the moment as i need the car in the air to get underneath. gap was very close when installed, althoough i have not measured it. Any suggestions on GAP?
I am leaning towards the VR sensor/ Bracket, althought there is no flex in the bracket. Could it be a faulty VR sensor??
Why would this effect the MAP switching or the output???
the most frustrating thing of all is the engine runs so sweet with MJLT that i donot want / Cannot go back to the standard dizzy..



Image

Watch the rev counter in this video clip:


Image

http://s245.photobucket.com/albums/gg51 ... nt=082.flv

910esprit
Posts: 46
Joined: Tue Feb 26, 2008 10:07 pm
Location: Portsmouth england

Update: on the home straight

Post by 910esprit »

Got some time to have alook at the car today, Looks like i am on my way to solving the problem.
The VR bracket and Gap are perfect, no movement on the bracket and the gap could not get any smaller with out touching the wheel.
A bit confused it decided to unplug the VR sensor and remove it. this is what i found......
Image

The wire had broken under the sheath and was intermittent obviously on the over run the movment of the engine on the mounts made the connection fail i Gues it flexed the cable when it move about.
Replaced the plug and resecured the cable this time to the bracket to remove the movement from the plug soldered joints.
Ran perfectly with no misfire.
Now all i have to do is reconfigure twin maps and see if this is cured as well.
Can anyone tell me how the VR sensor baing intermittent can effect the MAP switching or is there another problem???

brentp
Site Admin
Posts: 6275
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

It looks like you found your problem! If you still see that flickering try to rewire it with a 5V reference as described in my post. When it seems to be 'switching maps' does it also report the switch event in the software?
Brent Picasso
CEO and Founder, Autosport Labs
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