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help with VEMS/MSNS in Bristol?
se7ensport - 22/8/08 at 06:42 PM

Hi folks

Been trying to get TB's running on pinto for a while and it's doing my nut!

I'm running GSXR750 tbs and VEMS ecu (uses megatune software).

I've set the reg fuel, using AlphaN and got a rough map but it's not even spluttering...

Spark map is fine as I ran on carbs for a ages, I just can't get it to start and would appreciate a second head if anyone is up for the challenge over the weekend????



Thanks

Alex



[Edited on 22/8/08 by se7ensport]


Werner Van Loock - 22/8/08 at 08:02 PM

are the fuel injectors firing? It's common that fuel injectors that have not been used for a long time tend to get stuck

Try them directly on 12v, you should hear them click, if not then they're either broken or stuck

And what about te fuel pressure? You are using a injection pump now right?


Did you buy the vems pre-built? If so, does it have injection FET's inside? As you were only using ignition only at first.

[Edited on 22/8/08 by Werner Van Loock]


se7ensport - 22/8/08 at 08:21 PM

Hey Werner

I'm running 3.1bar with the injection pump.

I've taken the TB's off of the manifold and I can see them spraying fuel so I'm confident that they are at least opening & closing (VEMS prebuilt and does fire injectors).

I suspect I've got something basic wrong, it was always a bit of a sod to start on carbs when cold so tomorrow I'll put the carbs on and get it up to temp to give me the best hope of getting it running.


Alex


rusty nuts - 22/8/08 at 09:02 PM

Leave the T/Bs on and give it a squirt of brake cleaner , if it fires then the ignition should be close enough to get it running .If you can keep it going for a few seconds it should warm up . Had a similar problem when I first got my Emerald ecu up and running when I had the engine running I was able to increase the cold fueling and cranking enrichment


the_fbi - 22/8/08 at 10:58 PM

I know you say it was running on carbs before so the plugs should be firing, but have you checked that are still firing now?

If you're not even getting a cough yet you have fuel, then its gotta be sparks or air, I'm guessing the throttle is opening OK, so earths and anything which controls the spark.


se7ensport - 25/8/08 at 12:51 PM

These are the settings I'm using, the req fuel should have been 13.5, but by increasing the value it began to try & start, however, I still can't get it to start, any suggestions welcome.

I put the carbs on and it fires straight up and runs smoothly.

[img][/img]


rusty nuts - 25/8/08 at 02:02 PM

By 13.5 I take it you mean air fuel ratio? That would be fine for a hot engine but you need more fuel when cold. Carbs have a choke to supply this , with injection you need to add more when cold.


se7ensport - 25/8/08 at 02:21 PM

Hi Rusty

13.5 is the required fuel from this calc:

req_fuel = 6.49 * (D / N / I)
I injector flowrate (cc/min)
D engine displacement (cc)
N number of injectors (eg. 4 for a 4 cyl port injection)

req_fuel = 6.49 * ( 2000 / 4 / 240 ) = 13.5


the_fbi - 25/8/08 at 02:47 PM

quote:
Originally posted by se7ensport
Hi Rusty

13.5 is the required fuel from this calc:

req_fuel = 6.49 * (D / N / I)
I injector flowrate (cc/min)
D engine displacement (cc)
N number of injectors (eg. 4 for a 4 cyl port injection)

req_fuel = 6.49 * ( 2000 / 4 / 240 ) = 13.5

afaik the standard injectors at 19lb which is around 190 cc/min. That said, I'm sure there are a variety of different ones so perhaps the 240 is correct or you're not using the stock gsxr750 ones.


se7ensport - 25/8/08 at 03:08 PM

they are from a K4 (2004) bike, I'm struggling to find a source that states size - will try the calc with 190cc and see if it works; it gives me 17.1.

[Edited on 25/8/08 by se7ensport]


chasmon - 27/8/08 at 09:40 PM

Oki doki a couple of observations. Your req fuel may well be way off as the calculations don't work well for a non American v8 engine Good news is once you get it started it alls becomes soo much easier and enjoyable!

AFAIK 260 is the correct flow rate @3bar for 750 and 1000s from that year but I have actually set mine lower as it gives you finer adjustment by scaling up the numbers in the VE table...

I think you probably have your configurator settings wrong as the VE table has KPa displayed at the top where it should be TPS

To set the system to use TPS you need to set it to Alpha-N this has to be done in two places... On my version of Megatune its in "Engine constants" and also in File=>configurator look for "tuning algorithm" or something similar.

My experience comes from Megasquirt but on that you need to have the TPS raw settings on the left hand side which according to your max min TPS should be 45ish to 200ish (just outside the avaialble range).

(MSII uses 0 to 100% TPS calc'd on the RAW max/min values set, don't know about VEMS...)

Hope this helps, may not all be right for VEMS though. There are people around running pintos on Megasquirt so hopefully someone can lend you a map you can convert...

HTH