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Discussion Starter #1
Hi

2.4 210 Blanked EGR...

At 119,8 i have a surge in pressure while at max. Throttle..Funny thing is Boost pressure is very close to desired pressure...& nowhere near max. Pressure

When cold i have pretty close disered and actual boost pressure, but when warm the actual pressure drops to 800-850 mBar when requested is 1000-1020 mBar.

Airflow through MAF is very close on desired/actual when normal straight out driving at steady speed. When acceleration, the desired is far above actual & at idle the actual flow is like 1/4 above desired.

Anyone got a clue to what´s playing up...K&N filter on her, problem started after cambelt snapped (no damage, happened at idle with generatorbelt eaten by cambelt :censored: ), but both marks on belt fits & also tested with camlock & hmm...mm-gauge on cyl 1...
 

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Hi

2.4 210 Blanked EGR...

At 119,8 i have a surge in pressure while at max. Throttle..Funny thing is Boost pressure is very close to desired pressure...& nowhere near max. Pressure

When cold i have pretty close disered and actual boost pressure, but when warm the actual pressure drops to 800-850 mBar when requested is 1000-1020 mBar.

Airflow through MAF is very close on desired/actual when normal straight out driving at steady speed. When acceleration, the desired is far above actual & at idle the actual flow is like 1/4 above desired.

Anyone got a clue to what´s playing up...K&N filter on her, problem started after cambelt snapped (no damage, happened at idle with generatorbelt eaten by cambelt :censored: ), but both marks on belt fits & also tested with camlock & hmm...mm-gauge on cyl 1...
very similar to my graphs... i though it was normal... will watch this thread closely
 

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you may have one or more issues
first off your maf readings are way too low for given boost, this could be map sensor reading high.

try logging atmospheric pressure and actual boost pressure, start the car log for a few seconds then ignition off for a few seconds and back on without cranking or starting for a few seconds then crank and start for a few seconds.
this should compare the map sensor to real atmospheric at ambient condition and then when running at idle, it should be fairly close to atmospheric reading and shouldn't alter that much when running at idle maybe 50mbar or less ? if you let it log for too long before cranking it may revert to a false reading(mine stays at 1013mbar after a certain time(when just ign on not running))

or it could be maf sensor reading too low .
this could be a few things , maf gone , restricted inlet coked in carbon , swirl flaps stuck shut, inlet antishudder flap stuck closed partially closed, split turbo inlet hose maf to turbo or breather pipes that join after maf.
all could give a low air flow yet high boost pressure occur.

with egr physically blanked I think the 2.4 should be somewhere around 485mg/I of maf at around 1000mbar atmospheric , so 960mg/i @2000mbar 1150mg/I @2400mbar etc
straight away maf low at idle looks suspicious, as its less likely to be splits in hose as theres not really much vacuum to bypass the maf.

you could do with a donar car to swap map and maf sensors to confirm after checking visuals mentioned above.
you could unplug the maf and test drive, car should revert to internal maf values derived from boost values.
also you could add total fuel to a log, low maf values will restrict fuel qty
actual boost and vnt % appears to suggest its not a choked intake or map sensor over reading as I would expect it to be dropping vnt more on max boost areas.
the strange thing to me is where the boost pressure drops into 800mbar ? unless its function of antishudder flap working with egr to create vaccum to draw egr , your egr is blocked but maybe antishudder still partially closes where egr would have been active.
 

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Discussion Starter #5
you may have one or more issues
first off your maf readings are way too low for given boost, this could be map sensor reading high.

try logging atmospheric pressure and actual boost pressure, start the car log for a few seconds then ignition off for a few seconds and back on without cranking or starting for a few seconds then crank and start for a few seconds.
this should compare the map sensor to real atmospheric at ambient condition and then when running at idle, it should be fairly close to atmospheric reading and shouldn't alter that much when running at idle maybe 50mbar or less ? if you let it log for too long before cranking it may revert to a false reading(mine stays at 1013mbar after a certain time(when just ign on not running))

or it could be maf sensor reading too low .
this could be a few things , maf gone , restricted inlet coked in carbon , swirl flaps stuck shut, inlet antishudder flap stuck closed partially closed, split turbo inlet hose maf to turbo or breather pipes that join after maf.
all could give a low air flow yet high boost pressure occur.

with egr physically blanked I think the 2.4 should be somewhere around 485mg/I of maf at around 1000mbar atmospheric , so 960mg/i @2000mbar 1150mg/I @2400mbar etc
straight away maf low at idle looks suspicious, as its less likely to be splits in hose as theres not really much vacuum to bypass the maf.

you could do with a donar car to swap map and maf sensors to confirm after checking visuals mentioned above.
you could unplug the maf and test drive, car should revert to internal maf values derived from boost values.
also you could add total fuel to a log, low maf values will restrict fuel qty
actual boost and vnt % appears to suggest its not a choked intake or map sensor over reading as I would expect it to be dropping vnt more on max boost areas.
the strange thing to me is where the boost pressure drops into 800mbar ? unless its function of antishudder flap working with egr to create vaccum to draw egr , your egr is blocked but maybe antishudder still partially closes where egr would have been active.
Good point with MAP/atmospheric pressure :) See attachment, they looks fine in my eyes.

I remembered i had a new MAP in stock, so drop that in..No change.

I did also open to the shutter today. It was wide open...Should that be closed when car is stopped, or does it open after stopping & thats what you hear a few secs after the engine stops?

I think shes perhaps like 3-5 MPG down from when it happend? she does approx 37 MPG at 65 MPH on straight out level roads..

At 1000 RP/m theres a judder, otherwise engine is very smooth, perhaps a bit rough from overfueling (Black smoke when max torque & <3K revs)

I have looked through the pipes in the inlet from MAF to manifold (Except IC), but no obvious leakage.

You might just have explained to me why the 800mBar thing is happening, as this have really mystified me..Especially cause it only does it when warm

Tomorrow ill try to get hold of a tirevalve & then put the entire inlet under small pressure & then do a thorough leak-test.

Thank you so much for your time & inputs for now :)
 

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Discussion Starter #6
Just went for a drive without MAF connected...No change to better whatsoever...I have read about quite a few that have problems with turbo overshooting & due to change of map to "defaults", car goes into a safe mode..( not limp-home mode), where it drives quite good..Cant say so on mine..It actually produced a lot of black smoke when high on tourque at medium revs.

Has had EGR blanked for last 55000 Miles..shes at approx 120.000 Miles now..& experienced no problems with soot before the fault occured..I mostly do 70-130 Miles long runs with her & often push her a bit, so dont think soot is involved. Will check swirls for leaks tomorrow as well :)
 

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Discussion Starter #7
Leaking swirlflaps :-(

https://youtu.be/b18U6bq6QNM

Could this be enough to a high loss <2000 RPM ? 3 out of 5 does like the most obvious one :-(

Although its VERY strange that this should happend at exactly same time as cambelt snaps...Perhaps the trapped air when engine locked up put way to much pressure in there & made the path..IF that actually is THE reason for no low end power & the smoking
 

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well its leaking for sure but how much boost its losing from there ? who knows.
but the fact your suggesting a boost leak via the swirl flaps, If all else were equal the maf values would actually go up higher than normal as the turbo would be sucking more air than is getting to the manifold.
if the map sensors are correct it still looks like a restriction in manifold or low reading maf / leak after maf ?
yes the antishudder just closes momentarily on shut down and then opens again.
the 800mbar im sure ive seen on here before but I think it was a 2.0jtdm ill try to search if normal or not.
or a restriction on exhaust even ?
does I have dpf if so may have differential pressure available on multiscan.
 

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Discussion Starter #9 (Edited)
True...Looking for plugs ATM..Although your deadright about the low airflow...Although still puzzles me it does the same when no MAF connected.

I have DPF at the moment, but when it happened, the DPF was not on, so no difference/reason there. I remeber seening the DP-sensor in multiscan a few days ago, do not remember exact numbers, but 4-8 mBar at idle.

Caravanwashing & summertires are on program for today & busy till Tuesday..Thanks for your inputs so far :)
 

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Discussion Starter #10 (Edited)
Today i loosened the cam pulley while lockingtool installed in camshaft, while measuring TDC on cyl 1...It is & was dead on.

I made a video of its behaviour after this: https://youtu.be/HPsNQg2DGII Full throttle from when RPM goes from steady 1100 RPM to max RPM

The EML is only due to EGR blocked.

No leak in intake on either side of turbo (Swirldflaps a tiny little bit, but this fault been so, ever since belt snapped as described earlier...

Anyone got any idea on how to get my car back into former normal state with boost coming in from below 1500 RPM, not 2500, where although theres boost from 2000, it finally takes off, smokeing more than she should...
 

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Discussion Starter #12
Any news with this ?
Nope..Halfway through my 2 weeks offshore-duty, so unfortunately not..

Im still mystified by why theres vacuum in inlet at idle when shes warm (could be VGT-related), but only then. (thinking, if theres vacuum in manifold at idle, fault cant be due to leaking swirls...)

I bought a hand-vacuum pump, so will test VGT when i return & see if thats why...Although its had ovencleaner on exhaust/VGT-side, so should be clean & still, the behaviour has been there ever since cambelt snapped & a lot better low down torque before..
 

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Discussion Starter #13
So...Had inlet off, Swirls removed...No change whatsoever :-(

I then tried to override the VNT solenoid & give VNT full vacuum...Hey presto, I got, (was very careful with this, although MAP-sensor should protect), full boost at 1500 RP/m compared to +21-2200 RP/m with solenoid inbetween.

Now what really makes me wonder...

I put a vacuum-meter on VNT-side of solenoid, which gave 460 mm HG at idle, directly on the vacumpump it was around 600 mm HG...All fine according to eLearn accodring to my conversions, so solenoid is fine.

Must say im really getting out of ideas by now :-(
 
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