Fuel System Decarboniser as seen on Wheeler Dealers?

[geeman237]

Wheeler Dealers was recently shown here in the US with the Jaguar XK8 episode. One thing they did to the car was clean the fuel system using a small machine called a Fuel System Decarboniser. Looks like 2 aerosol cans of cleaner etc were injected into the machine and this machine was hooked up to the car and run for about an hour at a high idle to decoke the engine etc.
I hadn't seen one of these things before. Are they any good? The results seemed so on the emissions readings.
I havea 1994 Jaguar XJS, 4 litre AJ6 engine. It has a slight miss that is only just detectable. I have replaced the plugs, rotor arm, distributor cap, coil, and plugs leads at a recent service and its not really made a difference. I listened to all the injectors with a mechanics stethascope and they all sound consistent. The car has done 103,000 miles. I try not to use 10% ethanol fuel that is the norm here in the US. Ed on ths show quoted about 70 pounds for this service. Considering the age and mileage of my car I thought it probably wouldn't hurt to try it. I have used Techron fuel system cleaner in the tank followed by a little thrash on the back roads, again, no perceptable change.
Comments? Experience?
Thanks

[The Wookie]

Nothing to add except I saw this episode and it was certainly a new one on me!

Would be interested in anyone's experiences

[geeman237]

Seems its been brought up before, see thread link below. Not very conclusive from the point of view of anyone actually having it done though.

http://www.pistonheads.com/GASSING/topic.asp?h=0&a...

[stevieturbo]

I'd be rather dubious.

If you genuinely think there is an engine issue, you need to do some proper diagnosis first.

ie, proper service, compression check etc.

It's rare they are at fault, but you could remove the injectors and have them cleaned or replaced. At the end of the day, no matter how good or bad the rest of the system is...these are a key part.

[Winky151]

Got nabbed by a marketing guy at the Classic Car show at the NEC last month asking if I'd heard about it:-
'yes, saw it on WD'
'We're just starting to licence some garages to do it would you be interested?'
'No not really as I re-built the engine about 10k miles ago'
'Oh, ok. Wouldn't be worth it then but on your size engine (S6 3.0 24V) it would be approx. £100'.

Just as a heads up for you.

[geeman237]

I emailed Terraclean and the nearest place with their equipment is about 3 hours away. Like I said I have replaced a lot of the serviceable items, plugs, etc and the injectors all sound OK. I did a compression check today, all looks good there.

1. 1 - 192psi
2. 2 - 192
3. 3 - 195
4. 4 - 195
5. 5 - 195
6. 6 - 190

Will have to dig deeper.
Thanks

[larsson7]

Total BMW has an article on it in the January 2013 issue, they tested it on a well cared for x5 3.0d with 133k on the clock, they gave it a good write up, apparently less black smoke on cold starts and kick-down, slightly better fuel consumption and reduced the co2 emissions from 0.78 to 0.62 although they expected the figure to improve with some more miles. Unfortunately they didn't mention the price, depends on car and engine.

[blitzracing]

I got some pretty impressive results from a catalyst cleaner you added to the fuel. The car had failed its MOT on emissions, so at around £15 it was worth a go. The product claimed a 30% reduction (sorry I cant remember which specific pollutant), but the before and after gas test did show a 30 % improvement. It still failed the MOT as the ECU had a fault, so the pollutant levels where much higher anyway. Point being- to get the pollutants to drop is no big deal, you just got to burn off anything that's stuck to the catalyst by whatever means, chemical or otherwise.

[Pumaracing]

Excellent compression test numbers. Given you've changed the electrics it's probably an injector with a poor spray pattern or volume. I'd suggest whipping them out and sending them to someone who can test the spray pattern and output and ultrasonically clean them. That normally restores proper function. I'm not a fan of stuff you add to the fuel that's supposed to do the same thing.

[geeman237]

Any idea how much an injector cleaning service is? The injectors for my XJS are no longer available and if you find any NOS they are very expensive.
Also see my post on Crank Speed Sensor as things are sort of duplicating on the threads.

Thanks again for all your comments and suggestions.