A problem....Help :-)

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>

Moderators: JeffC, rdoherty, stieg, brentp

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Jenko
Posts: 67
Joined: Thu Jan 11, 2007 11:02 am

A problem....Help :-)

Post by Jenko »

Hi,

It's me back again for some advice :-)

While out for a good blat this weekend, about half way, the developed a problem....Under load (i.e. foot to the floor), it would feel like it was losing all the advance and running into a brick wall, If I throttle up lightly, it would happile reach full revs....

It's difficult to describe the symptoms....but I can hear the engine change (it rasps, but has no drive)....It feels similar to when I used the basic map we have on this site, and found out there is a 0 at the max load on max revs .........

At a guess, it feels like the advance is blipping back to a low number........any ideas?.

Thanks.

Paul.

P.S. I've tried a few different maps, I've checked HT leads etc...one thing I do need to check is if it happens only when the car is Hot...........

MartinM
Posts: 433
Joined: Sat Aug 27, 2005 12:08 pm

Post by MartinM »

TPS or MAP or neither? Firmware version? Shift lights fitted and showing anything untoward?

If it's TPS and greater than V3.0.0 firmware have you calibrated the TPS using the Load Axis Calibration feature?

Need some more facts!

Martin

hammy
Posts: 19
Joined: Mon Aug 07, 2006 1:16 pm

Post by hammy »

Hi,

Dunno but ....

** Have you checked the gap between the crank sensor and the an the toothed wheel ??

** It could also be a noise problem -the latest MJ software has adjustable filtering ,have a look at it.

** You haven't set the rev linit too low by mistake ???

** Have you updated the firmware, I found this wrecks the stored map

Good luck
Hammy
X/F Wessie owner and forum Groupie

Jenko
Posts: 67
Joined: Thu Jan 11, 2007 11:02 am

Post by Jenko »

Hi Chaps....OK sorry, more info....

TPS, V3 board, running V3.1 S/W, TPS calibrated, shift lights do all light up when the engine looses power! (well spotted)..

I'm sure my VR sensor is doing what it should...I had some trouble with it previously, but feel I have sorted it now.....

Was wondering about the new software...I may give it a try, it's not a rev limit, if I keep my foot to the floor, the car will pick up and go......and I can get it to max revs if I accelerate slowly.....This problem only happens when accelerate hard...

Cheers.

Paul.

MartinM
Posts: 433
Joined: Sat Aug 27, 2005 12:08 pm

Post by MartinM »

I think you've got to try firmware V3.2.1 (and V3.2.1 Configurator) - shift lights lighting up mean that the MJLJ is thinking that the rpm is much higher than it really is, so you're probably getting the rev limiter kicking in and giving you the behaviour you're feeling.

Electrical noise seems to be the topic of the moment and V3.2.1 should be more appropriate if that is your problem - but as to why you might get it just on full load, I'm not sure :(

You've nothing to lose (apart from the map inside the MJLJ, so retrieve and save that first) - you can always revert to any previous version of the firmware.

Jenko
Posts: 67
Joined: Thu Jan 11, 2007 11:02 am

Post by Jenko »

MartinM wrote:I think you've got to try firmware V3.2.1 (and V3.2.1 Configurator) - shift lights lighting up mean that the MJLJ is thinking that the rpm is much higher than it really is, so you're probably getting the rev limiter kicking in and giving you the behaviour you're feeling.

Electrical noise seems to be the topic of the moment and V3.2.1 should be more appropriate if that is your problem - but as to why you might get it just on full load, I'm not sure :(

You've nothing to lose (apart from the map inside the MJLJ, so retrieve and save that first) - you can always revert to any previous version of the firmware.
Hiya Martin......

Point taken - I'll try the new Firmware this weekend - Many thanks.

Paul.

Jenko
Posts: 67
Joined: Thu Jan 11, 2007 11:02 am

Post by Jenko »

OK....I updgaded the firmware and Config version.....car now works perfectly :-) - Very pleased, I hope it stays like this - ....In fact tickover is now much smoother also.

I'm doing a club rolling road day in the next few weeks, so I hope I can come away with a good map - Once done I'll post on the maps page - Cheers....Paul.

brentp
Site Admin
Posts: 6282
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Paul,

That's great! I'm glad you were able to see an improvement. Chalk another one to the PIP noise filter. :)

Next time you drive try doing a long term data logging session to see if it captures any RPM spikes- would be good information to have.

Regards,
Brent Picasso
CEO and Founder, Autosport Labs
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Jenko
Posts: 67
Joined: Thu Jan 11, 2007 11:02 am

Post by Jenko »

brentp wrote:Paul,

That's great! I'm glad you were able to see an improvement. Chalk another one to the PIP noise filter. :)

Next time you drive try doing a long term data logging session to see if it captures any RPM spikes- would be good information to have.

Regards,
Will do - I know last time I data logged, there were spikes all over the place......But must say, since the new firmware down load, the engine feels much smoother on the over run and on tickover...............


Cheers.

Paul.

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