Supercharged 122ci engine, lean AFR display, 8mpg mileage :(
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Supercharged 122ci engine, lean AFR display, 8mpg mileage :(
Hi guys,
Just finished my setup done by a local tuner and been driving it for a couple hundred of miles around the city. Mpg is horrible (8-9) although AFR seems to be decent (13.6 on mid-throttle, 12.5 on full throttle, 14.7 at cruising throttle, 15.6 at idle).
Engine is a 4 cyl in-line French peugeot (85x88mm), DOHC 16v, using stock plugs gapped at 0.035". Injectors are Subaru 650cc@3bar. Fuel rail is pressurized @3.5bar with vacuumatic/boost adjustable FPR. Engine is supercharged with an Eaton M62 mk2 supercharger with dual throttle bodies (bigger one before charger for silence reasons, stock one after, just before intake manifold. Maximum boost that I get is around 16psi. Readings are done by Innovate MTX-L kit bought off the megasquirt site.
No pops or black smoke on the exhaust though. Shall I recalibrate lambda sensor?
I am also uploading the tune file and some city driving logs. Can any of you please look at them via logviewer and kindly let me know what's wrong?:(
Just finished my setup done by a local tuner and been driving it for a couple hundred of miles around the city. Mpg is horrible (8-9) although AFR seems to be decent (13.6 on mid-throttle, 12.5 on full throttle, 14.7 at cruising throttle, 15.6 at idle).
Engine is a 4 cyl in-line French peugeot (85x88mm), DOHC 16v, using stock plugs gapped at 0.035". Injectors are Subaru 650cc@3bar. Fuel rail is pressurized @3.5bar with vacuumatic/boost adjustable FPR. Engine is supercharged with an Eaton M62 mk2 supercharger with dual throttle bodies (bigger one before charger for silence reasons, stock one after, just before intake manifold. Maximum boost that I get is around 16psi. Readings are done by Innovate MTX-L kit bought off the megasquirt site.
No pops or black smoke on the exhaust though. Shall I recalibrate lambda sensor?
I am also uploading the tune file and some city driving logs. Can any of you please look at them via logviewer and kindly let me know what's wrong?:(
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Let's start with the very basics. What's the compression ratio on that engine? What is cranking compression pressure?
Edit: oops, I should have asked... has ignition timing been properly checked with a strobe light?
Edit: oops, I should have asked... has ignition timing been properly checked with a strobe light?
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Static compression 9.2:1 (originally 10.8:1 but would have been risky to go with that and over 15psi boost), decompression plate mounted.
The others were not measured.
I forgot something: first cranking on cold engine takes about 15 seconds until engine fires up. And a big pop on exhaust.
Injectors are also Subaru Denso blue, i suspect they have a wider cone than original Bosch ones but would this increase consumption so dramatically?!
The others were not measured.
I forgot something: first cranking on cold engine takes about 15 seconds until engine fires up. And a big pop on exhaust.
Injectors are also Subaru Denso blue, i suspect they have a wider cone than original Bosch ones but would this increase consumption so dramatically?!
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Checking ignition timing is essential.
Have you read your plugs? What colour are they? Are they uniform?
James
Have you read your plugs? What colour are they? Are they uniform?
James
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Plugs are fine Apparently no problem from there. I was wondering whether somebody can look on the uploaded log and come up with a conclusion.
I think my AFR table has something wrong.
I think my AFR table has something wrong.
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Proved out to be the afr table, running @AFR 12.5 in part throttle under boost is not a good idea. Gave it also 2 degrees advance and now I am @21.4 mpg. EGTs are below 500 degrees C.
I have a GM knock sensor connected to the engine, is there some timing autotune (like VEAL) using it for hunting the best timing for a certain engine status?
BTW VEAL has saved me lots of time and money, basically it pays itself in the first 5 gas tanks. I highly reccomend it.
This topic is more or less becoming a monologue, is there some official contact from Megasquirt so that I can discuss this with them?
I have a GM knock sensor connected to the engine, is there some timing autotune (like VEAL) using it for hunting the best timing for a certain engine status?
BTW VEAL has saved me lots of time and money, basically it pays itself in the first 5 gas tanks. I highly reccomend it.
This topic is more or less becoming a monologue, is there some official contact from Megasquirt so that I can discuss this with them?
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
"This topic is more or less becoming a monologue, is there some official contact from Megasquirt so that I can discuss this with them?"
Please explain that further. I have no clue what you are asking for.
Please explain that further. I have no clue what you are asking for.
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Something like an official troubleshooting support that I send logs to and then I get guidance.
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Contact your supplier.
Depending on what add-on support options you may have bought, your supplier and this forum are the primary support options.
James
Depending on what add-on support options you may have bought, your supplier and this forum are the primary support options.
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
You are saying troubleshooting support, but it reads like you want someone to tune the car for you. No ecu manufacturer would ever come to that party.deadrange2001 wrote:Something like an official troubleshooting support that I send logs to and then I get guidance.
Find the Manuals up top under Quick links: Manuals.
Cheers Luke
Cheers Luke
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
OK thanks but... no one seemed to issue an oppinion about uploaded logs&tune although clearly required by rules. Something like "hey dude your VE is too high for idling at your bore/stroke ratio" or "your afr table is not good". I have no idea whether I am doing the right or wrong tune.
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Okay, a few more comment for you to chew on...
1) What does that "local tuner" have to say about all this? Finishing the job with your original 8 mpg doesn't speak well about their original set-up.
2) What is the cranking compression? I asked before (no answer) to try getting a clue about the valve timing/duration.
3) It sound like the .msq has been changed to get you up into the 20+ mpg range, so
4) Speaking of run log and tune files, I only look at simple .msq and ,msl postings. If I have to go to an extra step, like unzip or another site to view them, I don't bother. Maybe I'm the only one with such an "attitude", but maybe you can get more help if you make it as easy as possible for us.
5) Neither the spark or VE tables look very likely to be correct in the (old) .msq, but they didn't look like a primary reason for the extremely poor (8 mpg) fuel economy that was being discussed then, so I didn't comment. Post that new tune/log files and let's have a new look.
6) It was asked (and answered, sort of...) before, but let's confirm that your ignition timing has been verified, preferably with a simple ( non dial-back) light and all the way up to the engine's rpm limit. If what is set in MS doesn't agree with what you see at the crank, and hold within a degree or so for the entire rpm range, then let's get that resolved first.
1) What does that "local tuner" have to say about all this? Finishing the job with your original 8 mpg doesn't speak well about their original set-up.
2) What is the cranking compression? I asked before (no answer) to try getting a clue about the valve timing/duration.
3) It sound like the .msq has been changed to get you up into the 20+ mpg range, so
4) Speaking of run log and tune files, I only look at simple .msq and ,msl postings. If I have to go to an extra step, like unzip or another site to view them, I don't bother. Maybe I'm the only one with such an "attitude", but maybe you can get more help if you make it as easy as possible for us.
5) Neither the spark or VE tables look very likely to be correct in the (old) .msq, but they didn't look like a primary reason for the extremely poor (8 mpg) fuel economy that was being discussed then, so I didn't comment. Post that new tune/log files and let's have a new look.
6) It was asked (and answered, sort of...) before, but let's confirm that your ignition timing has been verified, preferably with a simple ( non dial-back) light and all the way up to the engine's rpm limit. If what is set in MS doesn't agree with what you see at the crank, and hold within a degree or so for the entire rpm range, then let's get that resolved first.
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Re: Supercharged 122ci engine, lean AFR display, 8mpg mileag
Got the homework. Will try to get all these measured and come back. Thanks for the patience.