1.8 16v running woes!!

[dan7]

My bessy mate just bought a 1.8 16v with 131k on the clock. It idles ok, but when you rev it, it cuts out straight away. Any ideas please guys?

[amgine]

First thought would be an induction problem.

[Andy Jeffries]

generaly I'd say air mass sensor? but specificly Mk2 golf gti id not be 100% sure!

[Diamond Hell]

Check the induction hosing.  The 16V is a K-jet motor, which means it has no MAF as it's mechanical injection.  Instead it it needs to suck the rising plate up in the fuel metering head, or it won't get the fuel it needs to run.  If there's a split in the hosing then it'll stall when you open the throttle butterflies.  It could even be as simple as the hood at the metering head isn't secured over it - thus air is getting in there.... of course, it could be a lot more complex, but that would be a good point to start checking.

[Conker]

A simple one to try first...  Pull the intake boot off the metering head and make sure the metering plate....

a) Can be lifted up,
b) Can be pushed down a bit,
c) Is centralised,

Also, on the throttle body, check that the throttle cable pulls correctly on the throttle arm, and that the microswitch can be heard to "click" when the arm lifts off it (u will need the engine off to hear it).

[Diamond Hell]

a) Can be lifted up,
b) Can be pushed down a bit,
c) Is centralised,

Please don't do that - the K-jet metering plate is quite a sensitive device and won't take kindly to being 'pushed down a bit'.  It is adjusted to ensure the mixture is right - pushing down is likely to put it out of adjustment, which might seriously shorten the life of your engine.  I would suggest you only ever very carefully push it up from underneath - this will release fuel to the injectors, if the system is pressurised.

[Conker]

I was just going by haynes - says to check its freedom of movement?  I think it would only spray fuel if he had bridged the fuel pump relay.

[Diamond Hell]

It's not the spraying of fuel (at the injectors) that's an issue, although you might flood your engine doing that.

The danger is putting the metering head out of adjustment.  If they get really heavily out of adjustment it's possible to fill the cylinders with fuel so you can't even turn the engine over.  The opposite is also possible - after only a couple of hundred miles you wind up with a hole in a piston because the motor's running ultra lean.

Been down both routes (way back) and I'd hate to see other people having to make the same dumb mistakes as I have!