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ultrasonically cleaned my nozzles

4094 Views 3 Replies 3 Participants Last post by  chittychittybangbang
This weekend I removed the injectors from my 2002 Golf (ALH), with 95,000 miles, so that I could put the nozzles in my jewelery sized ultrasonic cleaner. I didn't really have any expectations, but just wanted to give it a try and let others know in case anyone else has been interested in the idea.

I wouldn't say I've noticed any differences in performance or anything. When my next tank of fuel runs down I can report back if fuel economy changed. I just put each nozzle into the cleaner for about 6 minutes and the fluid I used was regular Fuel injector cleaner that you can get from any parts store. There was some buildup of carbon on the injectors, but none really around the tip.
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Nice tip. I would bet carb cleaner or diesel specific fuel cleaner would also work. I would keep each nozzle matched to each injector though. I'd bet the injector themselves could use cleaning too, which is the benefit of running a can of diesel purge through the fuel lines.
Good point. I did keep the nozzles together with each injector and also stuck all of them back in their original cylinders.

One note of interest for others: After re-installing the injectors, 2 of them were leaking a bit of diesel around the bottom where the injector body meets the engine head. I tightened down the injector forks and that stopped the leaking on one, but not the other. The next day I started up the car and there were no leaks at all. So perhaps the new copper washers needed some time to hold their seal. Also, I had started and warmed the engine while it was leaking on the previous day, so probably having everything heat up and expand helped seal the washers.
The one thing you have to watch out for on the copper washers is proper seating. Some cheap washers which are advertised to fit are actually a tad too big and won't sit all the way down which causes compression leaks.

A common problem caused by following the injector replacement procedure for TDI 1z/ahu/alh injectors elsewhere is too low torque on the nozzle retaining nut which can cause diesel leaks. I wouldn't tighten down the injector forks too much because they have been known to shatter the arms. If it's fine I wouldn't tighten it further or try to loosen/reset it. It seems unbelieveable since it's the only thing holding the injector against the combustion pressures but it's been reported many times. My guess is that overtightening bends it in a direction which it just can't take. Both tips are on the injector replacement procedure in the FAQ here. You also have to make sure the fork washer is right side up but if it wasn't it would have snapped the washer or fork.

In addition to hot/cold cycles, sooty deposits from running could also seal things up.
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