omega 24 v6
|
 posted on 22/9/08 at 08:27 PM |
|
|
MSNS megasquirt comparison
Hi folks.
I have just spent the last hour comparing my Alpha N msq with that of a similar engine but a speed density setup.
The majority of the settings are so similar it's uncanny but there are a few that are differrent (as you'd expect).
I've had the beast running but after doing a steady idle tune (yes it was properly hot) I now find that I cannot for the life of me get it to
start first time with the key. The setup is an XE with gsxr itbs MSNS V2,2 board and wasted spark (2 off VB 921's). No idle valve fitted and no
choke or fast idle cable (at the moment I hope to be able to get it running without either). So does anyone have a similar setup on alpha n that I
could compare mines with? I know it won't be perfect or ideal but I could find out where I'm going wrong.
Should my crank timing be trigger return or time based?
What does the "hold Ign" in "spark settings" do? mines is set at 1
What does Min discharge in dwell setting do ? mines is set at 0.5 ( other comparison one set at 0.1)
Almost there with the whole car and any help would be great folks. I'l try and attach my msq
If it looks wrong it probably is wrong.
|
|
|
|
|
omega 24 v6
|
| posted on 23/9/08 at 07:48 AM |
|
|
 Over 100 views and 7 downloads but no comments. I'm a bit disappointed
If it looks wrong it probably is wrong.
|
|
|
JonBowden
|
| posted on 23/9/08 at 10:36 AM |
|
|
I have little knowledge of megasquirt but have installed an old rover V8 injection system many years ago.
I take it that the problem is cold starting?
Does the system use a cold start injector - my rover system did - perhaps modern systems just richen the mixture at start up.
Jon
|
|
|
martyn_16v
|
| posted on 23/9/08 at 11:08 AM |
|
|
Don't know what the Hold Ignition is, never noticed it before
Min Discharge is just that, the minimum time the coil is given to fully discharge. Normally MS will charge the coil for the Running Dwell time and
then leave it to discharge for the rest of the cycle. At high rpm the time available in one ignition cycle may not be enough to charge and then fully
discharge the coil. In this case, MS will ensure that the coil is allowed the Min Discharge time at the expense of getting the full running dwell
time.
Are we talking about hot or cold starts? Is it trying to start but not catching, or spluttering and then dying immediately after? If it's the
first then look at your cranking pulewdiths for the temp the engine is at. If it's the latter then you need to fiddle the afterstart
enrichments.
I'd be interested to see how you get on, it sounds uncannily similar to my setup 
|
|
|
omega 24 v6
|
| posted on 23/9/08 at 11:25 AM |
|
|
quote:
Are we talking about hot or cold starts? Is it trying to start but not catching, or spluttering and then dying immediately after? If it's the
first then look at your cranking pulewdiths for the temp the engine is at. If it's the latter then you need to fiddle the afterstart
enrichments.
We're talking about cold starts from overnight or longer.
It catches during turn over but will not keep running when the key is released. Also as i said when i did get it to idle and got a steady idle it was
only by leaning of the ve table quite considereably. As cold start is a combo of ve table pluse crank pluse warmup then logic would say that i needed
to up the fuel at cold but it already smells very petroly (nice word). I think I'll need to do ad data log and see if that shows up anything.
Trouble is that once it's going it runs no problem.
If it looks wrong it probably is wrong.
|
|
|
Jenko
|
| posted on 23/9/08 at 01:20 PM |
|
|
Possibly no help, but I had a similar problem...I got MS to run, but it was rough, then could not get it fire at all.....Turned out I blew the
VB921's, which I found to be very fragile, and a real pain to set up....So I switched to EDIS4 and never looked back....
Not saying this is the issue, but it could be, I would also advise anyone to use EDIS unless it can't be done with EDIS...I assume you are
running a V6, will EDIS 6 not work with this?....
|
|
|
martyn_16v
|
| posted on 23/9/08 at 02:34 PM |
|
|
Cold starts are a sod to tune, you only get one or two chances a day to try it so it takes forever. I don't know how much help I can be, just
stick in there really
|
|
|
omega 24 v6
|
| posted on 23/9/08 at 05:01 PM |
|
|
quote:
Possibly no help, but I had a similar problem...I got MS to run, but it was rough, then could not get it fire at all.....Turned out I blew the
VB921's, which I found to be very fragile, and a real pain to set up....So I switched to EDIS4 and never looked back.... Not saying this is the
issue, but it could be, I would also advise anyone to use EDIS unless it can't be done with EDIS...I assume you are running a V6, will EDIS 6
not work with this?....
No not a V6 it's an XE 4 cyl and it WILL run ok once going so not an ign or vb921 problem but thanks for the input.
Martyn_16v you've got it in a nutshell there. As it will fire and run for a couple of seconds it gradually heats up to the point that it will
start. So yes only once a day you get a shot at it.
If it looks wrong it probably is wrong.
|
|
|
Steve Lovelock
|
| posted on 23/9/08 at 06:09 PM |
|
|
Hello Gary,
I have a delicate cold start situation where by if I completely avoid using the throttle it will start and idle and after a few minutes I can then rev
it and go. I don't recall changing the cold start settings from the standard settings supplied when I installed the software. So I can only
suggest changing the throttle stop slightly as I only made physical changes in this area?
Good luck.
|
|
|
Jenko
|
| posted on 29/9/08 at 03:52 PM |
|
|
Does V2.2 have an ignition / injector test mode......V3 does, and I found this soooo useful for tracking down problems
Sounds like you need to go back to basics.....When it won't fire, do the standard checks....Are you getting fuel, spark, Compression.......Lets
assume compression is ok as it has started....
Could it be that you get some ignition on the first start, and then the engine gets flooded?..........Have you pulled the plugs to see if they are
wet?......
If the fuel seems ok.....Can you pull the plugs and see if you are still getting ignition when cranking?....
|
|
|
martyn_16v
|
| posted on 29/9/08 at 04:16 PM |
|
|
quote:
Originally posted by Jenko
Sounds like you need to go back to basics.....When it won't fire, do the standard checks....Are you getting fuel, spark, Compression.......Lets
assume compression is ok as it has started....
Too basic  It's running fine when warm so it's not really going to be a problem as such, it just needs some fettling of the cold start
settings.
|
|
|
