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Author: Subject: Megasquirt rich running problems
clairetoo

posted on 18/5/14 at 09:36 AM Reply With Quote
Megasquirt rich running problems

I've got a bit of a problem with my V6 - it drinks fuel like its 50p a litre..........average consumption is around 20mpg , no matter how I drive , with a similar setup to that which I ran in my Fury (and that would average over 30 , with a best of 41 !)

I figured I have to do something now , I just noticed the back of the car has a coating of black soot after a run up to Harrogate - cruising around 65 managed a stunning 24mpg.....

I'm using an LC1 and gauge , the AFR at cruise is around 15 - I suspected a dodgy sensor or LC1 , so I just swapped the one off my Fury , along with a new sensor - and the displayed readings are the same.......

I've tried three different sets of injectors , had numerous attempts at mapping it , even changed the entire throttle body setup..........and its official - I have no idea whats going on





Its cuz I is blond , innit

Claire xx

Will weld for food......

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Oddified

posted on 18/5/14 at 09:47 AM Reply With Quote
First make sure there's absolutely no leaks in the exhaust, that can make the afr read lean when it's actualy running rich.

Ian

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mark chandler

posted on 18/5/14 at 01:16 PM Reply With Quote
I thought I was having success tuning my car using a wideband sensor, when it went on a rolling road I gained 30bhp and the car was much nicer to drive.

Suggest you bite the bullet and get it set up on the rollers.

In my case I was adding to much fuel, I used autotune and tuner studio.

Regards Mark

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scudderfish

posted on 18/5/14 at 03:33 PM Reply With Quote
Go and see Dale at Bailey Performance http://baileyperformance.co.uk/ Not that far from you and does an excellent job.

Regards,
Dave

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coyoteboy

posted on 20/5/14 at 06:36 AM Reply With Quote
Timing is just as critical as fueling. You may notice that even at idle if you change timing by 10 degrees you see huge swings in apparent AFR. For example, my engine runs at 800rpm, 24kpa idle at ~15:1 using something around a 1.3ms d/c but also at 15:1, 34kpa with a 1.5ms d/c (I think I remembered those the correct was round but I don't have the logs handy to check!






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daxtojeiro

posted on 22/5/14 at 09:18 PM Reply With Quote
Email me a datalog of it driving for around half an hour at different speeds and the msq file
(Phil at extraefi . co . uk )
Phil

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clairetoo

posted on 22/5/14 at 09:35 PM Reply With Quote
quote:
Originally posted by daxtojeiro
Email me a datalog of it driving for around half an hour at different speeds and the msq file
(Phil at extraefi . co . uk )
Phil

Computer numpty question coming up.........how do I do that ? I have been running megasquirt for best part of ten years now , and still havnt worked that one out......

I also seem to be suffering from `wondering map syndrome'........drive it from cold , its fine , do a bit of auto-tuning , and its fine . Switch it off for ten minutes , and it runs completely differently - usually so waek it will barely run , spitting back and stalling , AFR's of around 18 to 20.........or it will be black smoking , super rich ?

This is all pushing me towards Omex.........there is no way I would get it rolling-roaded , since the map will only last untill its switched off......





Its cuz I is blond , innit

Claire xx

Will weld for food......

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BaileyPerformance

posted on 22/5/14 at 10:18 PM Reply With Quote
quote:
Originally posted by clairetoo
quote:
Originally posted by daxtojeiro
Email me a datalog of it driving for around half an hour at different speeds and the msq file
(Phil at extraefi . co . uk )
Phil

Computer numpty question coming up.........how do I do that ? I have been running megasquirt for best part of ten years now , and still havnt worked that one out......

I also seem to be suffering from `wondering map syndrome'........drive it from cold , its fine , do a bit of auto-tuning , and its fine . Switch it off for ten minutes , and it runs completely differently - usually so waek it will barely run , spitting back and stalling , AFR's of around 18 to 20.........or it will be black smoking , super rich ?

This is all pushing me towards Omex.........there is no way I would get it rolling-roaded , since the map will only last untill its switched off......


Where is your air temp sensor? Running lean from hot start can sometimes be down to false air temp reading.

It's nothing at all to do with what ECU you pick, if you can't sort megasquirt your less likely to sort OMEX. The tuning software fir megasquirt is simpler that MAP3000/4000 for OMEX.

You said wandering MAP? Assume your using Alpha N - if the the curser moves up without you moving the throttle you have noise issues.

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clairetoo

posted on 23/5/14 at 06:14 AM Reply With Quote
Not wondering MAP.......wondering map(ping).........the fuelling is different from one start to the next . Its fine every time with laptop plugged in , but I cant just run it - it needs constant fiddling .





Its cuz I is blond , innit

Claire xx

Will weld for food......

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BaileyPerformance

posted on 23/5/14 at 08:34 AM Reply With Quote
Check your air temp reading, heat soak (after a run) can heat up the sensor, on restart (due to a falsely high reading) puts less fuel in - causing lean mixture and poping. You then change something in the map to compensate.

Where is your air temp sensor?

Also, are your sure your throttle bodies are balanced spot on?

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daxtojeiro

posted on 23/5/14 at 09:36 AM Reply With Quote
Hi,
have a look here for info on how to datalog:
http://www.youtube.com/watch?v=D889vh7La0w

email me if you need a hand and I can show you what to do,
thanks
Phil

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Oddified

posted on 26/5/14 at 12:46 PM Reply With Quote
As well as the air temp sensor/heat soak mentioned, that can also be a sign that you've got to much idle advance and a virtualy closed throttle. Less idle ign advance, open the idle screw slightly to get the tick over back and the idle afr is much easier to get stable/consistent.

Ian

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clairetoo

posted on 29/5/14 at 09:56 PM Reply With Quote
Heat soak on the temp sensor was definitely a problem - its now moved to the rear of the airbox , in the airflow , and the readings are nice and stable .
I've tried backing off the timing at tickover - but how far can I go ? I'm down to 9 degrees BTDC , and its still ticking over faster than I like , despite being pulled back from 12 degrees........

The biggest problem is fuel consumption - no matter what I do with fueling or timing , no matter how I drive it , it does 20mpg..........and the rear of the car is covered in black soot , even running AFR's around 16 at cruise.





Its cuz I is blond , innit

Claire xx

Will weld for food......

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jwhatley

posted on 30/5/14 at 08:08 AM Reply With Quote
Are you running wideband control?

You ideally want a wideband lambada with AFR targets set, it will auto correct to the AFR set by you then.

Omex is a big step up from mega squirt. Why not look in to an emerald k3 or k6. They have plenty of options and all the map settings you will ever need plus Dave will probably be able to give you a fairly close base map to start with.

John

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Oddified

posted on 30/5/14 at 08:40 AM Reply With Quote
quote:
Originally posted by clairetoo
I've tried backing off the timing at tickover - but how far can I go ? I'm down to 9 degrees BTDC , and its still ticking over faster than I like , despite being pulled back from 12 degrees........


If the engine is fairly standard, there's no need to run lots of timing at idle, 4 or 5 degrees btdc is plenty. With an ecu the days of having to run lots of idle timing to compensate for a rubbish advance curve in a clockwork dizzy are long gone. Put some extra timing below the idle rpm sites to help the idle when cold/under load. On the other hand, most engines like lots of timing at light loads/cruising rpms ramping up to around 45 - 50 deg btdc and that has a huge effect on the mpg.

Ian

[Edited on 30/5/14 by Oddified]

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matt_gsxr

posted on 30/5/14 at 10:40 AM Reply With Quote
Where is the lambda probe? From what I remember you have dual exhausts all the way to the back.
Is it possible that one bank of cylinders is getting less airflow (hence rich, hence sooty) than the other bank, and you are measuring the healthy bank?

What do the plugs look like?


Wandering fueling, tricky. Fuel pressure regulator or some other source of variable fuel pressure would be my guess. Fuel tank vent valve, good quality pressure regulator, stable voltage to pump, clean fuel filters, no kinking of return line.





http://jpsc.org.uk/forum/

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BaileyPerformance

posted on 30/5/14 at 07:15 PM Reply With Quote
quote:
Originally posted by jwhatley
Are you running wideband control?

You ideally want a wideband lambada with AFR targets set, it will auto correct to the AFR set by you then.

Omex is a big step up from mega squirt. Why not look in to an emerald k3 or k6. They have plenty of options and all the map settings you will ever need plus Dave will probably be able to give you a fairly close base map to start with.

John


Megasquirt 2 will do all you need, omex 710 has no advantage at all over MS2. In fact tunerstudio is better then MAP3000 (having said that I'm told MAP4000 is better but not used it yet)

It's really daft to think simple tuning issues can be resolved with a change if ECU, the chances are the same problems will exist with Omex or emerald. The engine in question is basic, no fancy VVT or inlet manifolds.

We have installed megasquirt on all sorts of engines, always had good results, we have mapped over 100 MS's

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shaunod

posted on 12/6/14 at 10:31 PM Reply With Quote
Sounds like it just needs some close attention on the mapping. I defy anyone to explain why Omex, Emerald or pretty well any other after market system is 'better' than your MS2 for the job it is being used ... simply not true. In truth there is very little between them other than the software ... and Tuner Studio makes most of them look like year 10 software projects!

Get Bailey to map it for you ... or at least get someone out in the car with you to map it while you drive ... or do some data logging and send it to Phil (daxtojeiro) ... it sounds as though you have a few minor map setup issues that are causing you problems ... I would strongly recommend sticking with it .. spending a small fortune on another version of the hardware in a different box just doesn't make sense.

Just my opinion of course, but I am an Omex trained and approved installer!!

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clairetoo

posted on 13/6/14 at 06:02 AM Reply With Quote
I did get it on a rolling road for a full set up on Tuesday - with the emphasis firmly on smooth running and economy , not trying to squeeze every last horse out of it...........
It was very quickly found that the Lc1 wasn't reading right - and I had been relying on it for mapping.......
It now runs better , emissions and fueling along with timing sorted - and its made no difference

No matter how I drive it does 20mpg - and thats at 30mph , 60mph , or ragging the arse off it - everything points to running rich (black sooty exhaust) but its not ?





Its cuz I is blond , innit

Claire xx

Will weld for food......

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shaunod

posted on 13/6/14 at 08:43 AM Reply With Quote
Okay ... so the lambda in the exhaust is showing good readings ... but you are using too much fuel ... have you checked the exhaust temperatures on each exhaust header ? You must remember that the lambda reading you are relying on is a combination of all cylinders output ... if all of the cylinders are not running equally .. then you may have one weak cylinder which is making the AFR read what is a very rich mixture on the other cylinders and appear correct. I have had situations where one injector was barely firing .. leaving the mixture very weak on that cylinder .. but the overall exhaust looked about right .. try using either a decent pyrometer or a good laser temp gun to check that all cylinders are of close to equal temp. Check the dwell settings for the coil packs ... if they are wrong that will cause lambda values to vary. Confirm TDC mark on the pulley with a check on #1 piston (whip the plug out and check that the piston is at TDC when the mark on the pulley shows TDC)
My best advice would be to run the following tests;

1) Check exhaust temps - they should be within about 30 degrees C really.
2) Check the timing - as described above
3) Check the dwell settings for the coil pack - In tuner studio - Ignition settings
4) Try pulling one injector plug off at a time and see how the AFR is affected - if pulling one of makes little difference you have probably located the fault.

If all else fails - Give me a ring!

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DIY Si

posted on 13/6/14 at 10:37 AM Reply With Quote
Claire, where in the exhaust is your LC-1? Does it just read for one bank? If it does, it could be the other bank causing the problems but it won't show up. That's could also give a different reading between your LC-1 and a probe at the tail of the exhaust.





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DW100

posted on 13/6/14 at 11:37 AM Reply With Quote
Have you got consistent fuel pressure?
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shaunod

posted on 13/6/14 at 02:32 PM Reply With Quote
I am mapping in Derby on Sunday .. if you want me to pop in on the way home I would be glad to take a look.
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clairetoo

posted on 13/6/14 at 05:05 PM Reply With Quote
quote:
Originally posted by shaunod
I am mapping in Derby on Sunday .. if you want me to pop in on the way home I would be glad to take a look.

Feel free to pop round - there has to be something that no one has spotted yet................





Its cuz I is blond , innit

Claire xx

Will weld for food......

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BaileyPerformance

posted on 13/6/14 at 06:29 PM Reply With Quote
quote:
Originally posted by clairetoo
quote:
Originally posted by shaunod
I am mapping in Derby on Sunday .. if you want me to pop in on the way home I would be glad to take a look.

Feel free to pop round - there has to be something that no one has spotted yet................


Are you sure it's not misfiring? You posted a vid ages ago of you driving the car - it was on 5 cylinders at best.
The suggestion of checking header temp is a good one, you may have a miss (one header much cooler that the rest)

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