Nodge68
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The EDC needs the MAP signal, so it knows the boost pressure, and so how much fuel to add for full power operation, which bypasses the smoke map.
Why the difference in performance
- Thread starter dfossil
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GrumpyGel
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The smoke map will not be overridden - unless its a VAG ECU maybe.
Maybe @JC600 can tell us what's going on?
Well now - after a short intermission to re-decorate my Daughter's house - I have received a genuine Bosch MAF and fitted it - same part number came off.- not done the low pressure fuel pump and filter yet - change one thing at a time.
Now that's interesting............
With the new MAF my performance is a bit gentler at auto gear shifts from standstill than with the MAF unplugged but mid range is more similar to my Daughter's manual now - max fuel pressures obtained going up my test hill are more in line with that car too. It also seems to change up at higher revs than before - which aids sluggish Autobox cold morning takeoff..
When the MAF was unplugged the engine was definitely much rattlier - both at tickover and at light loading in town driving - but I could get the high fuel pressures that Nodge68 reported above and it went well.
On this new MAF I can no longer get the high fuel pressures that Nodge68 gets and I got with the MAF unplugged - but overall I have decent performance and a quiet engine - even quieter than on the old MAF
I wonder - is there any chance Nodge68 that your MAF is unplugged or defunct to the point that it runs in default? - the performance in default (unplugged) on mine was pretty bloomin' good! - just noisy.
Overall I am happy with the new MAF and have a quieter sprightlier Hippo.
Now that's interesting............
With the new MAF my performance is a bit gentler at auto gear shifts from standstill than with the MAF unplugged but mid range is more similar to my Daughter's manual now - max fuel pressures obtained going up my test hill are more in line with that car too. It also seems to change up at higher revs than before - which aids sluggish Autobox cold morning takeoff..
When the MAF was unplugged the engine was definitely much rattlier - both at tickover and at light loading in town driving - but I could get the high fuel pressures that Nodge68 reported above and it went well.
On this new MAF I can no longer get the high fuel pressures that Nodge68 gets and I got with the MAF unplugged - but overall I have decent performance and a quiet engine - even quieter than on the old MAF
I wonder - is there any chance Nodge68 that your MAF is unplugged or defunct to the point that it runs in default? - the performance in default (unplugged) on mine was pretty bloomin' good! - just noisy.
Overall I am happy with the new MAF and have a quieter sprightlier Hippo.
Nodge68
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I understand that there are slight variations in MAF output, between individual MAFs. This shouldn't be the case, but I've read about it somewhere.
I use a long steep local hill to do live data analysis. I also use manual gear selector, selecting 3rd and allow the RPM to hold full power. I then take the live data values from there.
Yeah - I did the same to achieve similar numbers to yours when the MAF was unplugged.
- but now I get lower fuel pressure - about 105000kpa - in the same situation but speed is about the same
When My MAF was unplugged I got P0100 - Air Flow Meter, and P0110 Air temp out of range - and an engine management light on the dash - I am sure you would have known if yours was doing that so I don't think your MAF is unplugged - but it is strange that the figures are so similar - yours to mine unplugged - whereas mine with new MAF and my Daughter's car fuel pressures are similar to each other but lower.
I am not conversant in the workings of the ECUs etc to put forward any explanation - but it seems to my simpleminded brain that as the sensors lose precision the car moves towards a default state - ups the pressure and shortens the injection to give acceptable performance at the expense of quietness, economy and refinement. That might be bollocks - I normally like to stick to facts and leave the guesswork to others
Nodge68
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- Near Newquay
My MAF is definitely plugged in, as it shows a MIL if it's not. I can't remember ,but I think I might have had the Synergy 2 fitted when I did the readings, which I used just for the MAF compensation feature. This could well push the MAF figure above the nominal standard figure.
Something I've always wanted to do was to disable the air flow monitor in the MAF, but retain the intake temperature reading. It's on my todo list, but I need to sort my gearbox out before messing with the MAF.
