16V running rich & adjustment screw broken argh!

[mikkijayne 0]

Hi guys,

 

Does anyone know what would cause a 1.8 16V to start running rich? Fuel consumption has gone up by 10-15% over the last few months and the exhaust stinks. It doesn't have a lambda probe so its not that, and unplugging the cold start injector has no effect. It starts and runs fine, although its lost a bit of pep.

 

I would just tweak it with the adjustment screw but some numpty PO has snapped it off :censored: So, I need to find out what's causing it in the first place. All the vacuum hoses are intact, the idle switch and ISV seem to be working fine. Any suggestions would be most welcome!

 

Thanks :)

[colinstubbs 0]

Couldn't be a blocked airfilter could it?

[davidwort 0]

Don't start fiddling with the CO screw if something else is likely to be the problem :)

You need to check the Warm Up Regulator is operating correctly and the thermo timeswitch on the right of the head is OK, I think Haynes has the correct resistances for these.

Check the Cold Start Valve isn't leaking or running when it should be off.

Could also be ropey injectors, wouldn't harm pulling them and checking the spray pattern.

[Supercharged 2]

I'm fairly sure you can buy the screw by the way but obviously depends if you can get the remains of it out...

 

As always i'd say Stealth are the best place to go to get a valver setup and the WUR adjusted but obviously worth checking everything you can first!

 

Have you still got your TDI Corrado ?

[mikkijayne 0]

Thanks guys. I agree on not adjusting anything if the cause is elsewhere. I just need to find it :?

 

Not the air filter - thats pretty clean. Could be the cold start valve leaking. I'll look at that if I can get it out without the bolts rounding off.

 

I'll check the thermo-time switch too. I have a spare one of those so fingers crossed.

 

You can buy the plastic plug for the CO screw, but Etka doesn't show the screw separately. I could get it out, but I'd have to strip the metering head, and thats not something that would go back together on a bank holiday Monday! Ditto pulling the injectors without having spare o-rings...

 

I'll do the electrical checks today and see where I get to :)

 

Oh, and yes I still have the TDI Corrado. Its sulking under a tree at the moment though, awaiting an engine rebuild :roll: