Loss of power

[MacBain]

Something seems to be wrong with my MK2 1.8 GL, when I press the accelerator all the way down to the floor it accelerates slowly while it sort of stutters.
It almost feels like i'm towing something heavy.
I know the catalysator has been gutted, could this cause these problems?
There's no decat pipe fitted, my cat is just a big emty box .

Since it is quite expensive to change the cat I was wondering what else I could check?

I've already changed the blue temp sensor, distributor cap, rotor arm and pluggs.

[rubjonny]

I had this and it turned out to be a loose spark plug, which ended up destroying itself!

[MacBain]

I just changed the plugs and they are not loose.

The petrol quality where I live isn't of the best quality, I always put on 95 octane, maybe som STP cleaner and a full tank of vpower 99 octane would help?

Should I use 95 or 98/99 octane at a regular basis?

[rubjonny]

next thing I would check is the lambda probe, 95 fuel wouldnt make it run that badly

Edit: Disconnect it 1st, if the car runs better you know the lambda is dead!

I take it you don't live in the UK and your car has an SPI unit not a carb?

[MacBain]

Where is the lambda probe located?
I live in Norway and the car has a mono-jetronic engine, so that means it's doesn't have a regular carburator doesn't it?
I've included a picture of my enginebay.

[rubjonny]

yep thats an SPI engine, the lambda probe is screwed directly into the exhaust downpipe.  If you find it and follow the wire up to a plug, disconnect this and see how the car performs

[MacBain]

I gave up on fixing this myself and turned the car over to my local vw shop, they adjusted the timing, changed the plugs (the ones I had put in wasn't the right ones  :embarassed:) and the plug-wires.

They also told me that there was a leak in the intake manifold gasket, and that they would have to remove the entire top in order to change this gasket, wich seems like a bit of an overkill in my opinion.
So I told them to leave the gasket for now.

The car seems to run much better now, but sometimes it jumps up to 2000rpm when idling, but only for a couple of seconds.
Is there an easy way to tell how major the leak is, would spraying some carb. cleaner/ startspray etc. on the manifold gasket reveal how serious the leak is?

By the way, there always seems to be a bit of oil gathering on top of the intake manifold, is this caused be the leak?

[rubjonny]

try nipping up the inlet manifold allen bolts, theres 6 of em. Some can be tricky to reach but with the right extention bits not so bad.  If that dont help theres no way you need to take the head off to do it!

[MacBain]

I'll look into it tomorrow, but I'm afraid that the bolts are very rusty.

What kind of symtoms would a leak in the intake gasket cause?

[rubjonny]

it would cause the mixture to lean out and the lambda would tell the ecu to dump more fuel in to compensate.