I am having problems with plugs fouling on My S5 T2 (no mods apart from 3mm seals, high flow air filter and high, flow exhaust).

I think that it is running rich due to poor gas mileage I get around (round town) 400 km to a tank when I dive like a grandma, and under 350km when I drive normally.
My mecanic suggests that the first port of call would be to do an ultrsonic clean and replace injectors,
I have spoken to 3 different mecahnics and I just get the feeling that they are willing to try things (at my expense) but are just guessing.
I'm no expert but would have thought that dirty/worn injectors would lean the mixture rather than make it rich
I have another thread re the same problem under the heading dirty spark plugs.

Any help would be appreciated.

 

Is this a new engine? If it is just breaking in, it will foul plugs quickly.

First, do a complete tuneup before you do anyting. New plugs, wires, fluid changes, O2 sensor, adjust TPS, etc.

If you are still having the problem, then have the injectors cleaned. It's cheap anyway, and should be done every few years.

 

350km to a tank? that doesn't sound bad on a T2.

 

IIRC, old injectors get junked up needle seats, which tends to unseat the needle in the rest position. This allows fuel to flow by, and creating a slightly richer condition. I higly doubt that it would cause your symptoms though.

 

The engine is a new rebuild but has been thouroghly run in, its done about 8000Km (not miles).

Is it necessary to replace all the fluids? this was done on the rebuild (I have changed the oil twice since then).

And for the plug leads they check out ok on a multimeter test should I replace them anyway?

Same for the 02 sensor it comes up fine on a voltage test.

How do you ajust the TPS?

Thanks

 

You serious????

I thought that the claimed MPG is 17 round town and 24 on highway??

 

have you tried changing your fuel filter??

 

X = 350/ 1.609 / ~16 gal tank. =...

13.595400870105655686761963952766

 

NO not yet but wouldn't that lean the mixture if it were clogged?

 

Yeah that's what I came up with also,
I checked out the poll on fuel economy in the 2nd gen forum and it seems that most people that are getting fuel ecomomy around the 13's are running fairly extensive mods, would a filter and exhaust make that much difference, I'd be interested to hear what other people are getting on their 'stock' t2's.