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Discussion Starter · #1 ·
Hi All I am new to this forum and have problem with my golf 1.8T.  When I accelerate the car holds back and its like it is misfiring or there is a problem with the boost.,  I have cleaned throttle body and MAF sensor makes no difference when I unplugged it and also tried a different Diverter valve and also a different N75 valve but no difference.  I get herrendous backfire from the exhaust and also have noticed that the boost gauge only spikes upto about 10psi and drops back down to vacum mode.even when I havent released the accelerator the boost is dropping before I change gear.  I have checked all the pipes all of them are samco and non of them are loose or have split..  Any help would be appreciated.....  Thanks in advance...... 
 

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Id re-check the boost pipe that runs from the top of the intercooler to the throttle.It can sometimes work a tiny bit loose

at the top the intercooler and leak boost.Especially when you have samco fitted.
 

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Discussion Starter · #4 ·
Thaks for that mate I have a FMIC and stripped the bumper and everthing else but there are no loose pipes.... The car just hols back like it is in limp mode could it be either the MAF or the coil packs possibily... Is there any way to check this out apart from VAG COM.. I tried while the car was running and removed one coil pack at a time and cant say really if it was worse or better as it was still misfiring... Does anyone know how much the MAF sensors should be from the steelers as I have been quoted £85.00 and that's if I give my old one in... My friend has the crypton software for VW's and I plugged it in and it came up wit the following errors:-

Air Intake quantity

Secondary Air solenoid valve

Does anyone know what these faults are please I am getting desperate and dont want to be buying parts if I do not need them any help from you folks would gratefully apperciated...... Thanks in advance...................
 

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Discussion Starter · #5 ·
bump bump... Is anyone out there....  I am buying a new MAF sensor tommorow to see if that is the issue... Any other suggestion welcome....
 

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What FMIC do you have fitted ? Have you checked it for cracks ?

Also the vacuum pipe that runs to the divertor valve is prone to becoming brittle and cracking so id give that a check too.
 

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Air Intake quantity

Secondary Air solenoid valve
Air intake quantity sounds to me like the maf could be giving false readings to the ecu

and is the secondary air solenoid valve the N75 valve ? Not sure if it is, (tom might know.. he's good with more in depth knowledge.. sorry tom [:p]) but I just have a feeling that might be pointing to the N75 valve which can also go belly up too.
 

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Discussion Starter · #9 ·
Thanks for that guys ok here goes.... Have changed tha vacum pipes well all the ones I can see and they are all new now...It is an AGU engine code.. I have changed the N75 valve also and it aint that either....I will change the MAF sensor tommorow and see if it is that.... The intercooler is custom made and not sure exactly without running it how I could check for leaks Anyone done this before????? I cant see any dents on it??? all pipes are ok.... I am keen to find out what the secondary solenoid valve is and what the problem could be with it anyone know where it is... Its not that thing under the inlet manifold is it???? There seems to be tqo sensor type things there..................... I'll you know if it was the MAF sensor as the old one is only 8 months old... Is there any chance it could be the coil packs....................

Thanks again
 

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Discussion Starter · #11 ·
That's what I though they are going to go at some point so I have ordered 4 new ones from the steelers see pick them up tommorow... Will try them also if not then well I have  apsare set...... Really p**** me of now just want to get it sorted it is well fraustrating....................
 

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you beat me to it.Was gonna suggest cleaning the pins with a pen knife.

I had the same problem on my agu.Although it turned out to be the ecu ignition driver that had gone.Wasnt cheap.
 

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Discussion Starter · #14 ·
Ok have some results....I got hold of a new MAF meter today and it didnt work at first so I disconnected the battery for an hour and then started the car up not touching the accelerator the revs went up to 1200rpm and surely enough after 6 mins the revs dropped back down to the normal level and it was time for the test.... The car flew like a fippin aeroplane and the old love and zing came back........... Can you beleive that this is my second one in 7 months????????? Could it be my CAI kit that is causing the MAF to get mucky more quickly have checked the filter again and it is clean as a whistle inside and gets a regular clean...............

Although I have noticed a bit if a flat spot sometimes around 4-5k revs... Have ordered the coils packs and they will go on tommorow.... Have to thank all you guys for the help so far has been most usefull.... Oh by the way I dont have the ignition amplifier on the air box I have a CAI kit and I never had one.. I think they are built into the coil packs is that true on the later car mine is a 2000 model The engine I currently have in the car is from an Audi TT (180 BHP)but still has AGU on it..... Does anyone also know if the engine has been changed (this was done by the previous owner as he blew the old engine idiot had NOS in the car) if the bit where it has the engine code could be from the old engine as I am not sure Audi TT's came with an AGU engine. The original engine I beleive was an ARZ well that's what it says in the boot on the sticker...............

Thanks
 

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Discussion Starter · #15 ·
Ok it seems that I spoke too soon..  As the car is now not misfiring I have another issue...  I took it for a long spin and it seems to go well then all of a sudden I noticed that the boost gauge gets to about 10psi it sometimes drops and then the EPC light came on...  Pressed the accelerator and limp mode no power at all wouldnt even rev.  If I turn the car off and on again it is fine... Any ideas if it isnt one thing its another WE WIL GET THERE..........Just a matter of time and of course the reddies...............
 

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Discussion Starter · #16 ·
So Anyone ever had a problem with the EPC light coming on and the boost dropping My guess is that the car is overboosting and the EPC is cutting it for safety......HELP......BUMP BUMP.............................
 

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It sounds like the previous owner fitted an AGU head on the ARZ bottom end.This is because the AGU has bigger ports

so allow more air to pass thru producing more top end power.Your EPC issue sounds like a throttle body problem.

I think your gonna need vag.com or your mates diagnostic machine to perform a throttle body alignment and you should be ok.

Out of interest when did you last change your spark plugs? When you start running higher than standard boost on your motor

the standard plugs are gonna give up sooner than normal, have they been checked ?
 

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mmm, sounds like an interesting car you have there (bit like mine, vw wouldn't have a clue if they had to get parts for it!) have you still got a throttle cable or not? I have a cai too and my ignition amplifier is just cable tied to the back of the engine bay.
 

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Discussion Starter · #19 ·
Hi Guys... Thanks for the replies............ As far as I know the engine is out of a Audi TT (180 BHP).. Although the top of the head where the engine tag is still saying AGU but is it possible the previous owner changed the engine and just left the AGU top engine cover on it is that possible or is where the tag is located part of the whole head........ The car is a DBW and does not have a throttle cable.... I have recently changed the plugs so they should be ok.....I mate has a AGU with an ignition amplifier but I definatly dont have one anywhere near the airbox I am pretty sure these coil packs have it built in as my coil packs look nothing like my mates who has an orginal AGU engine... I have cleaned the throttle body (which wasnt that dirty) do I really need to align it using VAG COM as when I cleaned it and put it back on did the leave the door and bonnet open thing and the revs did settle down to normal after a minute or two..

What gap should the spark plugs be??? As they are the standard steeler ones for the car and are only 3 days old... I didnt check the gap before I replaced them.... Also what N75 valve should be best for my car I am currently running a F version....... Is that correct?????

Thanks again.......
 
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