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Author: Subject: Any MegaSquirt experts?
BKLOCO

posted on 29/3/06 at 09:52 PM Reply With Quote
Any MegaSquirt experts?

Can anyone help me to sort this out as it is driving me crazy.
I am running MS II V3 on a 2.0L Ford Zetec.
I am trying to set up the required fuel and I am getting nowhere fast!
My injectors are ND beige High impedence the flow rate of which I believe is 213cc/min.
When I run the required fuel calc it comes up with a figure of 15.8 So far so good.
I then generate a VE table using the original Ford figures for BHP and Torque and the table seems to generate fine.
When I start the engine it is so rich it is unbelievable.
The only way I can get the engine anywhere near stioc is by reducing the Req Fuel to about 4 !!!!! it seems funny that this is approx 1/4 of the calculated req fuel. (one cylinders worth)
The other thing that happens is that if I change the number of squirts field on the req fuel page this has a drastic effect on the mixture. Surely this should not be the case as changing from say 1 squirt to 2 should also inject half the fuel on each squirt. Mine doesn't seem to do this it just doubles the ammount of fuel injected.
I guess I have just got a parameter set wrong somewhere but I have spent hours looking and everything seems fine.
Unless I am continually reading something wrongly.
This is driving me mad.
Heeeeeelp!
Regards
Brian

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stevebubs

posted on 29/3/06 at 10:16 PM Reply With Quote
lots of 'squirters on the se7ens mailing list

www.se7ens.net

Stephen

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Rob Lane

posted on 30/3/06 at 07:25 AM Reply With Quote
The required fuel sounds reasonably OK, it will be the generated table that's rich. It's mentioned in help files.

Try reducing whole table by factor 5. You can do this in the table menu under 'Table transform' then shift (not scale) and enter a factor. i.e. if highest reading is 100 and you shift by -10 then it will end up as 90 and likewise all other values reduce by 10.
Positive values add to whole table figures , negative values reduce whole table. It will do this whilst connected to a running engine.

I had this problem, in fact still have at moment when I loaded new 029l code. It's well known the calculated tables are very rich.

What's your lowest and highest values?

If you have it running and want to tune out the richness in one go then go to Tuning/VE Table menu and use the ctrl-shift-arrow to lower values whilst running. Press F1 for correct keys.
You will be able to see tuning change on scale.

One more thought.
In the Constants menu you need PWM at 100 and time at 25.4 so injectors get full voltage on a high impedance set.




[Edited on 30/3/06 by Rob Lane]

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BKLOCO

posted on 30/3/06 at 07:50 AM Reply With Quote
Thanks for all that Rob.
Unfortunately it gets me no further forward.
The generated table looks about right from memory lowest values are around high 30's and highest around mid 80's. (What I would expect).
PWM settings are 100 and 25.4 so no probs there.
If I do what you say and leave the Req Fuel as is and adj the table I end up with a table that is effectively "on the floor" lowest reading at about 2 and highest at about 40ish. (not good)
I am starting to wonder now if something is corrupted in the firmware.
Any more suggestions will be gratefully received





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MikeR

posted on 30/3/06 at 08:16 AM Reply With Quote
I've not build my megasquirt yet and never played with a FI before but ......

are you sure your injectors are flowing what you're expecting? Could the fuel rail be at a higher pressure than normal or could these be higher capacity injecctors?

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Rob Lane

posted on 30/3/06 at 09:16 AM Reply With Quote
Hmm OK, 30's and 80's is right sort of values. That's a puzzle then.

Have you tried the req fuel calc in the manual pages at B&Gs site. Does it give same result ?

As I say I have same problem to the extent I've drowned two sets of plugs so far at £11 a set
Even had neat fuel out of exhaust at one point.

Since discovered that the cold start on the 4age was in action, this is an independently controlled injector direct in t/body. That cured my excessive richness.

I've now changed my table again and about to fit new plugs.

I'm in a position to change my ECU back at will and doing so immediately results in a smooth engine, plugs permitting. So there is something in MS that does not compute, as they say.

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Rob Lane

posted on 30/3/06 at 09:22 AM Reply With Quote
Brian,
Forgot to ask, what version are you running ?

I've just upgraded to 029l, the latest code considered nearly stable. I use this with MT2.25 . They have changed menus to a more logical approach for settings, saves jumping around.
Rob

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GeoffT

posted on 30/3/06 at 09:30 AM Reply With Quote
Just a few more suggestions, these apply to MS1, but probably are also relevent with MS2...

In the constants table, is Injector Port type set to port?

Check that you haven't got any crazy figures in the following parameters:-

Afterstart enrichment.
Warmup enrichment.
Acceleration enrichment.

You really need to be sure of the flow rate of your injectors, have you got reliable figures for these? If not it's worth testing one into a measuring jug to find out. Take great care if testing with petrol though, I used white spirit (hopefully the viscocities are roughly equal!) You'll need to have your fuel pressure regulator plumbed in to your test setup when you do this.

If all else fails a search on the MS forums will yield many more suggetions.

Good luck, Geoff.






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Rob Lane

posted on 30/3/06 at 11:56 AM Reply With Quote
Port type no longer matters. James has now greyed out that feature as it actually did nothing.
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BKLOCO

posted on 30/3/06 at 01:08 PM Reply With Quote
quote:
Originally posted by Rob Lane
Brian,
Forgot to ask, what version are you running ?>>>>>>MSII V3.0....version 2.35 code and MT 2.25....

I've just upgraded to 029l, the latest code considered nearly stable. I use this with MT2.25 . They have changed menus to a more logical approach for settings, saves jumping around.
Rob






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BKLOCO

posted on 30/3/06 at 01:15 PM Reply With Quote
quote:
Originally posted by GeoffT
Just a few more suggestions, these apply to MS1, but probably are also relevent with MS2...

In the constants table, is Injector Port type set to port?>>>>Yes

Check that you haven't got any crazy figures in the following parameters:-

Afterstart enrichment.>>>>Still the same when ASE is off
Warmup enrichment.>>>>Still the same when WUE is off
Acceleration enrichment.>>>>Not checked but shouldn't affect it at constant revs

You really need to be sure of the flow rate of your injectors, have you got reliable figures for these?>>>>Injector data vfrom 3 different lists on various web sites and from ChrisW so I'm guessing its right.
If all else fails a search on the MS forums will yield many more suggetions.>>>>Posted this question on European MS forums and had no replies yet.




Thanks to all for suggestions so far.





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Rob Lane

posted on 30/3/06 at 02:32 PM Reply With Quote
Ah, MS II has more code parameters, not familiar with that one. A different processor/software system.
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Rob Lane

posted on 30/3/06 at 04:19 PM Reply With Quote
Brian,
See this post :-

Constants, injector time

Interesting !

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GeoffT

posted on 30/3/06 at 04:32 PM Reply With Quote
Hmm....strange. I notice that suggestions re: fuel pressure/regulator have already been made on the MS forum, so I imagine you're onto those. May also be worth switching off EGO correction (set controller authority to 0%) just in case a dodgy o2 sensor input is sending things haywire.

You're right about MS compensating for the number of squirts - you should see the greyed box under your req fuel box changing as you alter the number of squirts (assuming MS2 is the same as MS1 in this respect) - is this happening? If not maybe you have a problem with the embedded code, and it's worth reloading it. Probably best to wait to see what ideas you get from the MS forum, they usually seem to fix most problems....eventually....






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BKLOCO

posted on 30/3/06 at 05:55 PM Reply With Quote
quote:
Originally posted by Rob Lane
Brian,
See this post :-

Constants, injector time

Interesting !


That is UNBELIEVABLE I have spent most of the afternoon on the EFI forums and found this thread myself and had deceided to investigate this tomorrow. It could explain the fueling changes when I change the number of squirts.
Thanks for that Rob





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BKLOCO

posted on 30/3/06 at 06:03 PM Reply With Quote
I think I'm going to try to measure the flow rates if my injectors as I have now found a thread on the EFI forums that say the 2.0L Zetec standard injectors flow between 170 and 180cc/min @2.7 bar.
Gonna build a test rig!
In my engineering apprenticeship days I was always told "go back to first principals" so I guess I'm gonna have to start at the beginning and check out all the basics first. Flow rates, Rail pressure etc. etc.

Any brainwaves that anyone has are still more than welcome however.
Regards and thanks for the replies.
Brian.





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stevebubs

posted on 30/3/06 at 06:54 PM Reply With Quote
other option is to throw cash at it and splash out on an LC-1 or LM-1....
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BKLOCO

posted on 30/3/06 at 07:01 PM Reply With Quote
I have thought about this Steve but that is almost defeatist
Apart from that I went the Mega Squirt route partly for financial reasons.
If I go wideband then the cost gets closer to the commercial solution that I rejected initially.
I will probably do this eventually but I wanted to advance my knowledge of Fuel injection systems. Being a naturally lazy git the best way of doing this was to put myself in a situation where I was forced to learn....Mega Squirt certainly does that





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MikeP

posted on 31/3/06 at 12:45 AM Reply With Quote
One tip I was given early on - when tuning, give the car what it needs, not what you think it needs.

The VE values don't really matter - start from the default table, then adjust req_fuel till it runs at idle. Use autotune to get it close, and accept whatever VE values you end up with. If you want a range from 30-80 (or better xx-100), you can readjust req_fuel and rescale the table - the only advantage is you've got finer control over the fueling.

Changing the number of squirts also changes req_fuel. What it does is change the fuel distribution at idle, so you can use it to see what makes it idle best.

It really doesn't matter about your flow rate either, as long as the injectors are close to equal - again, just tune what the car wants, not what you think it needs.

If you post your msq we could look for anything unusual in your settings.

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BKLOCO

posted on 1/4/06 at 09:15 AM Reply With Quote
For MikeP and If anyone wants to have a look at my .msq config file then HERE
is the link to download it. (You will need MegaTune 2.25 to open it)
HERE is a screenshot of MT with the engine idling.





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MikeP

posted on 1/4/06 at 03:35 PM Reply With Quote
Can you post your megasquirt-II.ini file too? What version are you running?

Injector time is a fine tuning thing, like it mentions in the thread it'll throw off your table slightly as the conditions change - weather and such - you can leave it till you're happier with the base tuning.

Your MAP looks a little high at 52, are you running a wild cam? Does it bounce at idle? If so you may need to damp it a little to get a good idle. If you're cam isn't too wild then you're probably too lean or rich, and need to adjust req_fuel further.

I'd suggest that you pick a ve map, then adjust your req_fuel till you get a good idle - the lowest MAP you can get is a good hint too. Then go for gentle drives, using the auto-tune or the log viewer to tune cruise part of your map. You need to ignore the accel enrich until you get the cruise sorted. Then you can tweak from there with higher throttle openings, etc.

A wideband is pretty handy - I use mine as a tuning tool, when I've got my settings perfect (ha!) I'll swap out the WB for a cheap NB, and use the WB for other projects.

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BKLOCO

posted on 2/4/06 at 06:51 AM Reply With Quote
Thanks for the answers so far. all that helps to a degree but what happens is that when I generate the req fuel from the calculator it gives me 15.6 as a figure.
If I try to start the engine at this with the map generated by MT then there is no way. There is far to much fuel.
The only way to get the engine to start seems to be to lower the req fuel setting to around 8. (which is the value set when the above screen shot was taken.)
It gets no better when the engine has warmed up either so I don't think it is the ASE or WUE that is causing the problems.
I have checked rail pressure and it is 2.7 bar static and 2.0 bar running at idle. So the vac reg is working and 2.7 is the quoted pressure for my injectors.
I have measured my injector flows on the car rail, with the pump and reg that is being used on the installation and they are all within a few cc's of 110cc/min.
Any more suggestions?

[Edited on 2-4-06 by BKLOCO]





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GeoffT

posted on 2/4/06 at 10:07 AM Reply With Quote
Hi Brian,

Unfortunately I'm unable to view your .msq file as my mtune is set up for mnS-E. As some sort of comparison, I'm using a 1600 mildly tuned crossflow with 320cc injectors, this gives a req fuel figure of 8.4. When you factor in the greater o/p of your motor and the smaller injectors your req fuel of 15ish doesn't sound too far out.

My feeling is that you should accept this figure, and continue your efforts by reducing the VE numbers in the idle VE boxes (i.e. the lower left area) till you obtain a reasonable idle, and work the rest from there. As Mike has said, don't question the numbers, give it what it needs. Again as a guide, the lower left bin in my VE map (i.e. the idle box) is set to 24, ranging up to around 116 in the WOT areas. I'm actually using Alpha-n, but the VE numbers at the extremes of the VE map will be much the same.






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pigiron

posted on 28/5/14 at 09:25 AM Reply With Quote
Hello Brian,

I fell upon a this old thread of yours when searching for a solution.

I too have exactly the same problem ie very, very rich when trying to use the calculated required fuel and like you have been going crazy.

I was wondering if you ever got to the bottom of it and if yes, would you be kind enough to share the solution with me.



Regards.
John (Brittany France)

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BaileyPerformance

posted on 28/5/14 at 10:09 AM Reply With Quote
quote:
Originally posted by stevebubs
other option is to throw cash at it and splash out on an LC-1 or LM-1....


You will need a wideband to tune it anyway, you can't just guess the fuelling.

If your unsure take it to a rolling road (always best to do that anyway, your'll never get it 100% with guesswork)

The reg_fuel just sets the scale for the VE table, it's not super critical, adjust to get around 25/30 at idle with an AFR if 14ish.

2 squirts per cycle is fine, wire injectors 1 and 4 to output 1, 2 and 3 to output 2.

Check your fuel pressure, physically check it with an in line gauge.

www.baileyperformance.co.uk

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