Megasquirt Again

[Lewis205mi 1]

Were having another problem with megasquirt, the car runs well up to 5200 rpm then its like there is a soft cut rev limiter of some sort which there isnt.

 

The car doesnt miss fire or fart about it just holds its revs cleanly at 5200 rpm, have any of you guys got an idea of what it could be? ive been told it could be the vr pots need adjusting?

 

 

Thanks

[hcmini1989 16]

im unsure about the vr pots.try posting on msextra .what are you running tps or map sensor .

[Lewis205mi 1]

Its running of the map sensor, its weird cuz it revs happily up to 5200rpm, then just holds its revs.

 

Its definatly electrical as its just like a soft cut rev limiter.

 

 

Thanks

[hcmini1989 16]

Its running of the map sensor, its weird cuz it revs happily up to 5200rpm, then just holds its revs.

 

Its definatly electrical as its just like a soft cut rev limiter.

 

 

Thanks

sorry mate i cant help you mate there is a rev limiter built into megasquirt i think its under more setings on megatune try checking that .allso do you have a tps setup try changing to that and see if it goes any higher .

[andy0075 9 1 Cars]

I had the same problem with my engine (Xu9JAZ) . It only reved up to 3800U/min.

 

I have an MS2 V3.57 SMD. I have changed all the resistors from the tach input circuit

to 10kOhm ( R44, R45, R46, R48, R53, R54 and the C31 to 0,001µF / 50Volt Cer Radial )

 

This is the same setting like the old MS2 V3 ( not SMD ) and now it is working perfect.

 

Andy

[madspikes 41 1 Cars]

As said there are two types of rev limiter in MS software, a hard and soft limiter... Just double check that its not cutting in...

 

My other suggestion is to use tuner studio to log the crank sensor output, and check that its getting a good signal. Also do some data logs of the problem happening, and them post up. We might spot something you hadnt!!

 

What you checked the ignition map to make sure there arnt any funnies in that.

 

 

Mad.

Edited February 8, 2010 by madspikes

[Lewis205mi 1]

As said there are two types of rev limiter in MS software, a hard and soft limiter... Just double check that its not cutting in...

 

My other suggestion is to use tuner studio to log the crank sensor output, and check that its getting a good signal. Also do some data logs of the problem happening, and them post up. We might spot something you hadnt!!

 

What you checked the ignition map to make sure there arnt any funnies in that.

 

 

Mad.

 

That sounds like a good suggestion, we just had the car mapped again by a different mapper hes done a very good job with the mapping but we couldnt get our heads round why it wont rev past 5200 rpm he favours omex / emerald as he thinks megasquirt can be alot of hassle some times but kindly agreed to map it for us, he played around with the rev limiters but to no affect.

 

I remember the first time the car was initailly mapped by the first mapper, it wouldnt rev past 4000 rpm, then the guy reved the car up and had his collegue play with the vr pots which made it rev up to 7000rpm this is why i thought it could be that.

 

Can you down load tuner studio of msextra or is it part of the megatune program that i already have?

 

 

 

Lewis

[madspikes 41 1 Cars]

tuner studio

 

tuner studio is newer version of megatune, and has a lots more functions. YOu can have both megatune and TS installed at the same time no problem.

 

There is nothing wrong with MS, is just the people that use it! Other ECUs people dont normally build, install and setup themselves, or if they do they know what there doing... There is a great deal of scope to get it wrong with MS! Like my idle valve issues, I expect the problems I've got will come down to setting issues, or dodgy hardware, all of which would be my doing.

 

Sounds silly, but your not running out of injector duration are you? I doubt you are just a random off the wall thought!

 

Not trying to teach you how to suck eggs etc.. but some of these snap shots might help! Some time the simple things can be over looked.

 

Or:

 

 

 

Mad.

[Lewis205mi 1]

Cheers for that mate, i will have a look asap. Im defo gona get that tuner studio.

I think the megasquirt will be good when its working properly (once i have worked out how to use it properly). Il let you no how it goes.

 

 

Lewis