carefully clean the MAF sensor as well
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Ok, yes if its doing it off- boost that's different.. Check and clean the MAF connector anyway, you can wash the maf element in IPA.
I can't remember, did you check the dizzy timing is spot on? Correct rotor arm and good cap? I'm thinking this because off boost the ecu is making max advance..
Pretty sure the TPS would throw up an "intermittent" code.Comment
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little update, yec cap and arm are good
cleaned all connectors inc the 2 multi plugs on the bulk head with contact cleaner
no difference at all
went over all air/vacum connections under the bonnet inc intercooler join and inlet mani with a tin of carb cleaner to see if the engine drew it in , no change in idle , used a whole tin
so i would say no significant leaks under the bonnet
did a little test on the way home from work
it seems to do it at 2200-2500 rpm any gear , it doesnt do it if you rev through it its just if you sit at those revs with very light throttle
si is it down to load at these revs or is it rotation related? or throttle position related?
managed to get it to do it 3 times one after the other in second gear lol
watching wideband it did jump to lean all times , so is deffo cutting the fuel pump!
so i now know what its doing !
its doing the " mixture out of table thing" newsh was explaining
BUT what is the cause
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managed to get hold of a vacuum/ pressure pump, put 2bar pressure in the pipework off the inlet manifold and saw a drop in pressure in one of them (+heard it) it had a small leak just behind the battery
it was the one to ecu
fixed that , no change
was really happy to find it but it hasnt cured the problemComment
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try driving it with the MAF disconnected.Comment
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ok took it out for a quick drive, got it up to temp and unplugged mafs and it started running rich (on wideband afr guage), drove it nice and steady and it didnt do the problem , it struggled to accelerate as well lol , i guess this is how its meant to be with the mafs disconnected,
but is this because it is running rich and "masking" the fault or is it a fooked mafs but only at a certain point of measured air??
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Seems like it probably is a MAF problem, or a connection problem to the maf, fitting a new one will be interesting. I have a recurring problem that I've still not dealt with because it goes away for 6 months at a time but its to do with the connection to the maf, I just need to buy some crimps and remake the connector.Comment
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tried a new mafs , no different
i think it is to "specific" to be a mafs problem
it is almost every time @2400rpm , with light throttle,
interestingly enought , it goes slightly lean on the gauge @2100rpm just before it does it??
mrc supplied me with 2 fuel chips cause they have had a "idle " problem with various cars , so i tried the other chip, the problem is still there but it does run a tad richer than the other chip , it also runs almost perfect lambda at the point just before the CUT problem, which the other chip went a tad lean surelly at this point of throttle and rev range the car is running of the lambda etc and not on the map
im still none the wiser to the problem! im now just gonna put the old superchip back in just to resure my self its not a mapping/ chip problem
im gonna try another throttle position sensor tomorrow that a mate has in his garage
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Have you tried a new Lambda??
My RS2 used to give me a slight miss at about 2000rpm when the lambda was shot, gone the minute I replaced the lambda and doesnt lean out for that second at 2000rpm.The Red Baron
(R)S2 spec, 034 GT3071
Wagner Short Intake and Intercooler
Whiteline, Custom Shocks with external reservoirs
8pot calipers with A8 discs
VemsComment
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I would check all of your boost pipes first, even change them with new piping and connections.sigpicComment
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its not a misfire its a complete cut
im running a wide band lambda sensor and the factory ecu is recieving a narrow band signal from my wideband controller , this signal will be clearer and crisper than the standard lambda probe as it it a "calculated " signal
ps the wideband sensor is brand new and the gauge in the car reads lambda (14.7) all the time until on boost or wot or over the specified throttle position that starts using the "map"Comment
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you were right about the leak behind battery
but this fault is to specific for a boost leak cant see it my self . i think i have a leak from the intercooler seal but it is not enough to draw any air in under vacuum as i have been over everything with carb cleaner and none gets drawn in
ps dont forget the fault us at 2200/2400 rpm so no boost!Comment
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ok done a blink test today ,after resetting ecu first so any codes were current
came up with 2111 which is "engine speed (rpm) sensor"
this code did not apear last week
but the fault has become worse
so maybe when i checked before it was not a fault, also it didnt come up on a scanner this week it only worked on the old blink style checks!!
i then unplugged ecu and retested and it came back so i would say i have found the fault
i now have the figures to pin test the sensor and ill do that tomorrow, i have ordered a new sensor from audi today so if it does appear to be faulty tomorrow am i can go straight out and pick my new one up
will continue tomorrow.......................Comment
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If you can get a tin of leak test then use that as it is rubberdised, it will blow bubbles where the leak is that will stay until you wipe it off. I have seen the bar engineer using it before but it may only be available to trade.
Have you checked the Turbo because doesn't it windup around the 2300rpm mark. I have been dismantling my 3B and i found that the boost hose was almost perished around the engine and the front of the turbo.
Just a thought, probably wrong.
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