David_17
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| posted on 1/1/11 at 08:17 PM |
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Megasquirt beginner req fuel
Hi all. Just at the stage where i'm about ready to map my car. I'm new to megasquirt so i've read up on what i can to get a basic
understanding.
I'm struggling with the very basics, which should be easy...
I've read when first starting, it's best to adjust the required fuel in the engine constants page until the engine is warm. It says adjust
by 2ms at a time.
The problem i've got is, it won't let me change it??  What am I missing? lol. I can't type a number in or press the up/down
arrows. (i'm assuming it's the 2nd box down at the left?)
Can someone please point me in the right direction, i feel stupid. haha
Cheers
Dave
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David_17
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| posted on 1/1/11 at 08:31 PM |
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Just done a bit more reading, it looks as if it's the top box i should be changing, but why are there adjustment arrows that don't work on
the 2nd box down??
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martyn_16v
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| posted on 1/1/11 at 09:00 PM |
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I think it's just a 'feature' of Tunerstudio not actually specifically knowing what it's writing in each dialog from the
outset, it creates all of the dialogs from the ini file depending on what firmware you're using.
The second one is a scaled req_fuel value depending on how many squirts/cycle you have set.
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suparuss
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| posted on 2/1/11 at 11:52 AM |
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the required fuel should be calculated using your engine and injector characteristics and left alone (to begin with) you then make adjustments to your
map. the megamanual gives you an ideal starting point the constants depending on your setup, you dont really need to change from this to start
with.
the first thing you need to do from there is get the engine warm and then adjust the whole fuel map up or down to get the lowest Manifold Absolute
Pressure you can at idle, this is then your starting point for tuning the engine. without a stable idle you cant really go very far.
cheers,
Russ.
[Edited on 2/1/11 by suparuss]
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David_17
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| posted on 2/1/11 at 01:19 PM |
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Cheers Russ.
I've had a play with it this morning and managed to get it warm and idling but i had to adjust the required fuel from 11.8 to 4.5 which seems
wrong..
I'm using TPS, not MAP as i've got throttle bodies. How do i adjust the entire map with tunerstudio??
Sorry for all the noob questions - But hope you can help. 
http://www.youtube.com/watch?v=K2HGrPbpaBE
Cheers
Dave
[Edited on 2/1/11 by David_17]
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daxtojeiro
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| posted on 2/1/11 at 02:16 PM |
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Dave,
the req_fuel value is used to scale the VE table for your engine to make the values in the table of a reasonable range.
So it is very important to get it roughly correct from the start! Dont get hung up on the numbers, but if your haveing to run with wildly different
values then something is wrong. Before you start tuning have a good read of my site, start here and work your way through the 3 or 4 pages I have on
basic setup: http://www.extraefi.co.uk/starting.htm
I see your running TPS based, if thats the case then you need to select Alpha_N not Speed density, thats probably why your having to have such a low
req_fuel.
If you need anymore help then load your msq file up with what the setup is and injector sizes, etc,
cheers
Phil
[Edited on 2/1/11 by daxtojeiro]
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David_17
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| posted on 2/1/11 at 02:24 PM |
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Thanks for the reply Phil.
It's your guide i've been using (came on a disc with the ecu) 
I'm struggling at the point where it says to put the req fuel to where it should be then click "TOOLS - VE Specific - Reset ReqFuel"
I can't find that in tuner studio, or is it done differently? also, if i put it at the original value of 11.8 it's very rich, where as
4.5 seems about right.
Can you help.. what should i be doing?? lol
Also, can anyone confirm the injector flow rate of 2.0 zetec standard injectors?
Cheers
Dave
[Edited on 2/1/11 by David_17]
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matt_gsxr
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| posted on 2/1/11 at 09:55 PM |
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David,
Nice start video, I always like those.
To move the whole table up/down in TunerStudio. Basic Setting ->Fuel VE Table1 Then select all the values click-drag. Then you can use the up
or down triangles to alter the fueling in the whole table.
Are your water and air temperatures being read correctly (check on the gauges), if the engine thinks its very cold then it can put in extra fuel.
What about the MAP sensor. Even if you don't use it for the load, it can be used (secondary fuel load, multiply MAP). If you have not
connected the MAP up, then it will be giving more fuel than it would with a MAP of 40kPa. Personally I think this value is deceptive, as it looks
like it is dependent on whether you have secondary fuel load (which in my case is turned off, but it still uses it).
If you post a msl and msq then some bright spark who understands Zetec (not me) will almost certainly sort you out.
Matt
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David_17
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| posted on 2/1/11 at 10:07 PM |
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Cheers Mat.
I haven't got the MAP sensor connected, as i didn't think it would make any difference. I'll try that when i get chance. What sort
of req fuel value should a zetec be running on usually? Just so i know if i'm somewhere close.
The temp and throttle gauges are all reading fine.
Cheers
[Edited on 2/1/11 by David_17]
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daxtojeiro
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| posted on 3/1/11 at 07:20 PM |
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Hi,
ensure you have alpha_n selected as you have speed density on the screen shot.
Ive just realised I havent updated the manuals since we went over to TS from MT. The best method is to calculate the scaling needed to get the VE
table correct.
Your having to change the Req_fuel from 11.8 to 4.5 which is 4.5/11.8 = 0.4 (new req_fuel / current req_fuel)
So go into the VE table, highlight the whole table (right click on one corner and drag to the opposite corner) then click on the "*" in
the top right corner.
Type in 0.4
Now you have scaled the VE table and you can go back to the original req_fuel value.
Dont connect the MAP sensor, you have an MS1 not an MS2, you can use the map sensor for constant baro correction if you want to, if not just leave it
disconnected
Phil
[Edited on 3/1/11 by daxtojeiro]
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David_17
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| posted on 3/1/11 at 07:50 PM |
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Great stuff. Thanks for that, it helps alot.
Someone's said aim for as low a MAP reading as possible at idle, but if using TPS, do i get it as close to 14.7 AFR instead?
(the screen shot is borrowed from google images, mine is alpha n)
Thanks again.
Dave
[Edited on 3/1/11 by David_17]
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daxtojeiro
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| posted on 4/1/11 at 06:55 AM |
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Old school methods were to adjust the timing to pull as low a vacuum as possible, but these days with lambda sensors and accurate timing gauges you
can simply adjust everything to get it as it should be.
Have a play with it and see how yours runs best, obviously if you need to pass emmission tests then youll need to get the idle sorted out for that
test, so 14.7 would be best,
cheers
Phil
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coozer
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| posted on 5/1/11 at 09:00 PM |
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Bring you lappy up to mine and have a look at my map
Steve
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coyoteboy
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| posted on 7/1/11 at 08:31 AM |
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Part of your probs are that you're tuning with TS but the tuning manual was written for Megatune. If you're aware of what's what you
can switch between them just fine and both do the task fine, but some things are named differently and TS seems to have lost it's internal help
(when you press F1 in a dialog it used to list the options and some hints.
Assuming your injectors are sized approximately correctly for your engine, the initial req_fuel calculator should be pretty close to the ideal value.
Which MS are you using, and which firmware?
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David_17
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| posted on 7/1/11 at 07:54 PM |
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Not sure on the firmware as i bought it off someone on here. It's MS1 029y??
If the spark angle was out, would that cause similar probems? As I havent been able to check that yet. The injectors are standard zetec ones with
gsxr throttle bodies.
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