B7 INJECTORS - ULTRASONIC CLEANING - ANYONE HAD IT DONE??

[polecat]

I have my car booked in for injector diagnostics and Cleaning next week, as im well down on power, and felt at 60k miles this was a logical step to have them ultrasonically cleaned, hopefully restoring the spray pattern etc, back to new, once all of the years of varnish from fuel is removed etc,,,,and hopefully increase in power.

Anyone with positive or negative feedback would be appreciated, as obviously ive got time to duck out if it is felt the negatives outweigh the positives?

On a slightly different note, what are the logical sequence of items to check for loss of power?,,,,,,my car has K&N Air Filter, Milltek with Valves,,,,BUT iS much down on power.
Cheers
Martinpolecat

[adsgreen]

Injectors I would have thought were ok as they would be exposed to the cleaning additives in all brands of petrol. I'd be very surprised given that very high pressure the injectors run at if they could really clog that bad - we're talking very high pressure here.

First point of contact for tracking lost power I would say is to look at the vacuum system and make sure there's no leaks or problems there.

Do you have any imperical readings for loss of power or is it the mk1 bckside test?

[polecat]

thanks for your opinion adsgreen - but all of the literature I have read over the years of driving, advises that the varnishes and laquers added to petrol, clog the injectors and reduce the spray pattern, bla bla, and loss of power -----I dont really think this in dispute.

I dont have any readings on loss of power, just my experience with my previous cars - Ev08, Accord Type R, Sierra Cosworth,,,,,,,,and I know the car isnt pulling 300bhp, let alone anywhere near the claimed figures.

I could pay £50 for a dyno run to tell me the power is down,,,but,,,I already know that,so im not going to waste 50 bar on that,,,would rather spend money on the items sorting power out, then get a dyno run.
Cheers

[adsgreen]

Yes whilst I agree fuel injectors can clog it's not something that is common as it once was. All petrol have detergents in them and for example Shell use the same fuel cleaning additives accross all the range not just VPower. Coupled with older injector being a couple bar in pressure (my track car runs about 2-3 bar or 40-50 psi) FSI runs anywhere from 50-200 bar - nearly 3,000 psi.

Now if you were experiencing an injector problem causing more than a 25% drop in power then the engine would be running incredibly lean - you'd easily be able to test this from measuring the exhaust gases to give the indication on combustion efficiency. I'd also be surprised if serious internal damage hasn't already occured by running so lean.

The problem with the cars you've listed is that all of them are either turbo charged or run a very simplistic cariable cam - I know when driving the accord tye r the cam change over was purely rev based and you ended up getting a kick almost akin to turbo lag. The RS4 being a N/A V8 with a much smoother cam kick is less noticable and doesn't have a lot (relatively speaking) of low down torque. Not saying it's not down on power but the v8 will drive very different to those cars.

Now one thing tat does occur to me is that I'm sure Doug from MRC has mentioned before that if the ECU detects a vacuum issue it'll restrict the engine and timing to something like 260ps.
This is dead easy to check as all you need is some OBD diagnostics that can report theignition advance. If it's retarded that the ecu is in protection mode and limiting power.
Really worth checking vacuum as this is a common issue ad I've not heard much go wrong with the FSI injectiors.

[polecat]

Adsgreen - I think your right, the latter sounding what im probably experiencing, but im getting no fault codes coming up on indicator panel,,,,,,,,,,

is the vacuum checking an Audi stealer job?

[adsgreen]

It's annoying but doesn't always trip the malfunction lights.
They can do it but will charge £100 diagnostic at least.

One option if you have a friend handy is to get a boost gauge that can read vacuum an plug it into the vacuum system and go fr a drive.
If you can find somebody nearby with a vag-com diagnostic tool then you can run the vcuum tests which takes ten minutes.
To be honest, another quick n dirty method is to unplug the vacuum line and see if it hisses. No hiss on disconnect means a leak somewhere.
If you have a hand vacuum gauge/pump then you can disconnect each vacuum line and manually test them to see if they hold pressure. theres a tech not on this somewhere.

do the exhaust valves work? If they don't then can be a signbut if they do work doesn't mean there isn't a leak. It's very possible that under low throttle conditions the vacuum is being replenished faster than it's leaking so hides the problem. Under full throtle there is no vacuum produced naturally by the engine so a secondary pump is used.
Hmm - just noticed your profile you have "not far from the toon". IIRC arn't revolution cars up that way? far cheaper than a audi dealer.

[adsgreen]

Just checked - yes
http://www.revolution247.com
NE8 2QX

[polecat]

Cheers - taking it in on Monday to Revolution, lets see. Thanks again.

[MB2]

Injector cleaning/matching was considered the last step on race bikes so I doubt you would see much improvement on a road car so agree, a vacuum test/RR/heath check would be were my money went too.