Wierd problem - please help (yes already replaced the MAF : P)

[sonic_vi]

ok, got a 2001 leon cupra (well turbo sport but same difference ) 85k on the clock.

about a week ago my car threw a bit of a strop on the motorway when i had my foot down in 4th. stuttered a bit, CEL came on and into limp home mode we go.

Turns out it was the MAF according to vag-com - ok no worries.

so today, new MAF installed and i am now getting this from VAG-COM

Address 01 -------------------------------------------------------
Controller: 06A 906 032 HN
Component: 1.8L R4/5VT 0002
Coding: 11510
Shop #: WSC 13623
VSSZZZ1MZ2R003841 SEZ7Z0A1200387
2 Faults Found:
16487 - Mass Air Flow Sensor (G70): Signal too High
P0103 - 35-10 - - - Intermittent
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 35-00 - -


these are the only 2 faults.

if i clear all the codes and start the car, the idle is a bit dodgy and it sounds kinda like it may cut out but no fault codes appear.

try to drive it and its like someone has put kangaroo petrol in it.

takes off like a nutter for about a second with LOADS of boost and then cuts the power right down (i mean like i have hit a wall !) then it comes back on for a second (whiplash ensues) and then cuts out etc etc until it cuts to limp home mode and aside from the lack of power all is well.

if i clear the codes the MAF sensor signal too high sometimes doesn't appear.

also it feels like there is too much fuel going through, (if i rev it standing still it pops and bangs like a b1tch)

have checked that the DV is secure and no obvious holes in the pipes and stuff (or disconnected ) and ensured the new MAF sensor has clean terminals etc same with the plug.

mods are maxflow induction kit, forge 007p and a stainless cat back system.

i am majorly puzzled.

All i can think is maybe there is a small split in a pipe somewhere and when the boost comes on it opens the split and drops the boost off. Is this likely or a common occurence.

please help as i am at a complete loss

 

[sonic_vi]

bump

anyone help? please i am desperate

 

[Saul]

where you get the maf from? its not unknown for people to buy a new one thats already bust

could also be a boost leak as you say, check the vacuum pipes as these are most common

you may need some outside assistance on this one, might be worth trying awesome gti (given your location) or someone similar

 

[sonic_vi]

got it from ebay, got a 30000 mile warranty with it so may send it back.

where are the vacuum pipes.

I can see how the boost system works just don't know what the different bits are called.

Are the vac pipes the ones that run over the top of the engine to the dump valve.

I have also taken the induction kit off and replaced with the standard airbox for diagnosis.

now the overreading MAF error has gone but as soon as i clear the check DV error it starts to stutter and pop and fart a bit until it pops back into limp home mode after about 20 secs.

if you have a pic or can describe which hoses to check and where i can do that.

replacing and checking basic stuff i can do, its just scarier stuff i steer clear of.

CHeers#

Russ

 

[Nathanio]

n75 valve? Does the coil pack failure give a similar problem (diesel here i'm afraid!)

 

[DPJ]

MAF reading too high would fool the CPU into thinking more air is entering the system than actually is.

MAP sensor (?) would disagree with this, hence the second fault code???

Car would also overfuel against what the MAF is telling the CPU?

Sounds like a dodgy MAF to me!

 

[sonic_vi]

I have just noticed one of the jobbies that plugs into where the plugs are keeps popping out about a centimeter. shove it home car runs good for a bit, misses a bit after that and then open the bonnet has popped back out.

is this a coil? is it dead? not getting maf errors anymore, just the boost issue.

 

[sparky4309]

I know that i am slightly stealing your thread but i have just installed a new MAF on my 2000 (X Reg) Seat Leon Cupra 20v T, on its first outing, when the revs drop down to idle level it just cuts out.

Do i need to register this MAF with VAG COM or should it just work instantly? (I have literally connected it and driven off)

Thanks

 

[Feel]

I have just noticed one of the jobbies that plugs into where the plugs are keeps popping out about a centimeter. shove it home car runs good for a bit, misses a bit after that and then open the bonnet has popped back out.

is this a coil? is it dead? not getting maf errors anymore, just the boost issue.

That is a colipack, yes - doesn't sound like it's gone just that it keeps popping off.

A new one would fit tighter, but you could also make and fit a bracket to hold the colipack down - it's been done before. Either side of the plug boss on the cam cover there's usually two threaded holes...

 

[sonic_vi]

That is a colipack, yes - doesn't sound like it's gone just that it keeps popping off.

A new one would fit tighter, but you could also make and fit a bracket to hold the colipack down - it's been done before. Either side of the plug boss on the cam cover there's usually two threaded holes...

cool

so the reason its reporting a boost leak is that the fuel isn't burning off, getting a misfire therefore boost level drops ala ecu thinks theres a boost leak.

I'll have to have a look

Cheers

 

[sonic_vi]

also as a point how do they stay in place?

do they clip onto the plugs or something?

seems odd that one is popping out but the others are cool

 

[sonic_vi]

I know that i am slightly stealing your thread but i have just installed a new MAF on my 2000 (X Reg) Seat Leon Cupra 20v T, on its first outing, when the revs drop down to idle level it just cuts out.

Do i need to register this MAF with VAG COM or should it just work instantly? (I have literally connected it and driven off)

Thanks

Thats kinda what i am getting when i clear all the faults on VAG COM.

maybe you have the same issue being a similar age of car?

have a check of the coilpacks. would be interesting if it was.

 

[sonic_vi]

OK update :-

just been out on my lunch

sorted the coil by crimping the bottom bit with a pair of pliers to keep it tight and in place.

now found that when i clear the error in vag com the following.

Rev the car standing still and it will pop and fart a bit at low revs but you can give it beans and no errors are thrown.

in gear - in first and second the car will bog down on putting your foot down but then will suddenly come to life with oodles of boost but then die again soon after, this happens until it goes into limp home mode.

only error being thrown is the check DV one

no other errors.

could this be plugs?

I am now thinking its not a boost pipe issue as when it comes on boost before going to limp home mode there is stacks of boost, it just dies off which you kinda wouldn't expect with a hole in a pipe. (maybe? or am i talking rubbish?)

could this be coils or plugs or something in the ignition.

plugs haven't been replaced since at least around 60k and its now on 85k

don't know how often they need doing?

 

[sonic_vi]

okay

I have found that the plug turned a tiny bit with the plug spanner and now in "limp" mode is boosting and dumping fine (better than before anyway and doesn't seem "slow") but when i reset the 17705 check DV error (thats the only one now) i get an erratic idle and when i put my foot down it will take off like a nutter only to cut all power about 1/2 a second later and then come back on line and then cut out again

I am really at a loss now.

what the hell could cause that. bear in mind that the car will boost fine in safe mode and still give me a fair bit of oomph (enough to bring the traction control into effect anyway)

gotta be something that is only being affected by high boost levels.

Can anyone think of anything?

Thanks in advance

Russ

 

[sonic_vi]

ok just checked and plugs are supposed to be changed every 40K

mine has now done 85k and i have owned since 63k and never changed plugs

i guess that they are 5k overdue,

weak spark + high boost = blown out spark & misfire yeah?

can someone confirm PLEASEEEEEEEEEEEEEEE !

cheers

Russ

(i understand the theory but the practical side is done on best guesses and a small budjet )

 

[DPJ]

Are you definitely no longer getting the MAF reading too high code?

 

[sonic_vi]

yeah definately not getting it

clear the error and the following happens.

on clearing the error there is a noticeable change in the idle. sounds a lot more "gruff" and it seems a bit lumpy.

just pops and bangs a bit when free revving not in gear but doesn't throw the error

when in gear, it takes off like a nutter for about 1/2 a second then bogs down and farts a bit like there is waaaaay too much fuel in the system, then comes on boost again for about 1/2 a second repeats this again and again and eventually just drops to soft limp mode and throws the 17705 P1297 error.

seems to only be a problem on high boost. Driving around at the moment in soft limp mode i can thrash the nuts off it and its boosting and dumping fine and doesn't seem to have any problem.

any ideas?

 

[sonic_vi]

ok changed the plugs

car drives a shed load better.........still have the check DV error tho

anyone got a diagram of the hoses to check?

Cheers

Russ

 

[sonic_vi]

OK just another quick update.

I am beginning to think this could be the new MAF reading too high

stuck my standard airbox back on and the MAF too high readings went away.

Could still be reading too high though just not high enough to get flagged.

unplugged the MAF and the car FLEW !

no boost errors just the MAF reading too low error.

would i still get a check DV error if the MAF was unplugged?

Cheers

Russ

 

[DPJ]

...............

would i still get a check DV error if the MAF was unplugged?

Cheers

Russ

With the MAF unplugged, the system doesn't know how much air it's getting, so it doesn't know it's losing any.