Quick one for you guys

[gibbygibson]

hi i have recently been having problems with my 1.8 gti 16v last week i disconnected my air meter unit from behind my air box to clean all the crap out when i put it back on the car wouldnt start so called the RAC out after a couple of hours trying to figure out what the problem was we disconnected the air meter unit form the big black air intake going upto the trottle body, she started but really juddering and popping wouldnt idle properly either. So where the meter connects the to the air intake i have put a little bit of tape over half of the hole and she starts and no popping the only thing is she now drinks alot of fuel, i have brought another air meter unit do i connect it up too the pipe then disconnect the battery for 15 minutes to reset the ECU? can anyone help?

[jezza16v]

I think you need to post some pics to show what bits you've been messing with as I'm not sure I know what you mean by 'air meter unit behind the air box'. The air metering unit is on top of the air box, the only thing I can recall being behind the air box on a 16v is the 'overrun cut off valve' which connects to the underside of the large throttle body pipe. The only other pipe I can recall connecting to the side of the throttle body pipe is the one from the idle stabilisation valve. If you've bu**ered the overrun cut off valve and it is stuck open then the engine will not start, the quick fix would be to blank the hole off completely but then the engine might 'run on' for a bit if you switch it off when its hot. The ISV is a bit more complicated, but again the engine should run with the connection blanked off but won't idle properly.........?    In any case there must be no air at all leaking into the large pipe to the throttle body or it won't run properly.

[Conker]

I think you need to post some pics to show what bits you've been messing with as I'm not sure I know what you mean by 'air meter unit behind the air box'. The air metering unit is on top of the air box, the only thing I can recall being behind the air box on a 16v is the 'overrun cut off valve' which connects to the underside of the large throttle body pipe.

My thoughts too.

Or he could mean the pressure valve saucer thingy?

 

[gibbygibson]

hi ya people i have just uploaded some pics of what i took off at the time is this the MAF or something else? also when i go to connect the bit up to the trottle body where the white tape is the engine goes to die, what can i do too stop this? would fitting a new one and resetting the ECU sort this out?

[mattkh]

HI
Thanks for the photo.
It is called the overrun cut-off valve.
Did you buy a new one ? And have you fitted the new one on ?

[gibbygibson]

hi i have managed to get another one from a scrapyard as mine was full with crud, havent put it on yet waiting for abit more info from you guys hopefully

[jezza16v]

That's the overrun cut of valve, it shoud be shut when the ignition is on. To get the car running you should seal off the hole to the throttle body pipe completely until you can replace it. There should be a short length of pipe from it up to the underside of the throttle body pipe. When you switch the ignition off the valve opens and breaks the vacuum to the inlet so it stops the engine. You should be able to check if its working by putting 12v across the contacts and see if you can blow through it, not sure which is + though.  You may have trouble stopping the engine when its hot though!!

[1982.rpd]

Mines plugged at the moment as I dont have a 90 spec 16v wiring loom also I cracked the valve so I run without one and its fine 

[gibbygibson]

just tried connecting the over run valve back upto the throttle body pipe still the same engine goes to cut out im really  whats needs doing to it to get it too run with the over run valve on

[jezza16v]

Check that there's some voltage getting to it when the ignition is turned on. Check the new one is working? if from a scrappy it may not be.