It has already been decided that the nozzles will be
replaced. Before we can do that we need to clean what will be reused and
measure these components to make sure they are still within tolerance. There has been a lot of talk in all this about 'pop' or 'crack' testing to ensure that the needle opens when it should and that the correct spray pattern is delivered. This is
DEFINITELY a concern and needs to be addressed. I will get to that after the cleaning.
I initially stated I would use my watch cleaning chemicals and equipment to clean these injectors and I confess that was in jest. There is no way I would put these in my £10,000.00 watch cleaning gear! However, I did experiment with the chemicals for a few reasons.
1. we need to remove dirt and that is best achieved with ultrasonic equipment. My watch gear is suited for that no doubt!
2. We need to remove oil as it traps dirt on precision equipment.
3. We need to make sure there is no residue and my cleaning solutions are VERY good at both of those.
I know that you will not be able to access this gear and to be honest, at £50.00 a change over for the chemicals (cleaning 1 injector as I found out before it was too contaminated) it just isn't cost effective. No worries, there are other ways to achieve the same goal. [disclaimer....I am not an idiot..I used old fluid that was destined for chemical pick up and was waste anyway. It was however far cleaner than the injectors!
]
I have a few cheap ultrasonic tanks that I use for cleaning dirty old clock components. Cost £10.00 each, or something stupid like that, and do the exact same job as the more expensive gear just not as well. For something as crude as an injector they are fine. I worked out a process using three of these tanks, but you can do it with one it will just take longer because you need to clean them between processes.
VERY,VERY,VERY IMPORTANT!!! DO NOT SUBMERSE THE WIRED PART OF THE 4TH INJECTOR!!! I am not sure if it would harm it as it is a magnet but since it will cost you £220.00 at least to replace it, there is no reason to chance it! Just keep the injector body of number 4 out of the tanks, inspect the ports for blockages, which I doubt will be there as they are pretty large holes, and leave it as is. Clean the nozzle retainer, shim,needle pin, nozzle spacer, and heat shield the same way as the rest of the injectors and set aside for assembly later.
I used petrol in the first stage. I know there are concerns but it will be cleaned off in the next processes. You can use diesel it will work the same way I just didn't have any in a can to hand. My little tanks run on a 3 minute cycle so I ran them for 3-4 cycles depending on how bad the injector was in the first stage. Essentially I ran them for 9 to 15 minutes to make sure the worst of the crap was broke up. Keeping in mind we are
replacing the nozzles, place the injector body, nozzle retainer, shim, compression spring, nozzle spacer, and heat shield in the tank for the petrol/diesel phase and the following phases.
DO THIS OUTSIDE! AS FUEL IS AGITATED BY ULTRASONIC IT VAPORIZES AND BECOMES VERY VOLATILE! YOU NEED LOTS OF VENTILATION! The tanks can handle it as the chemicals I use such as Horoleen are also volatile hence the expensive machine mentioned before that has lots of vacuum ventilation built in. Used outside and away from ignition sources it
should be fine but you are at your own peril here. You can use other substances but
you must be aware that whatever you use can
not harm the injectors precision surfaces and needs to be removed completely before reassembly.
First pic is before running the tank in petrol. second pic is after the 15 minutes. Note that you cant see the bottom of the tank anymore!
The next phase is simple. The parts will prob be warm to the touch, this is an effect of ultrasonic action and is normal. Use it to your advantage and let the petrol evaporate off the parts. (this is a reason why petrol may be better than diesel for this but the down side to petrol is that the parts are now open to rusting in ambient air where as diesel would coat them and protect against this.) Fairy liquid and water run in the tank the same way for the same time will remove any remaining petrol/diesel and also more contamination.
Caution! Only use a wee bit of Fairy (or similar) or you will have a soap bath on your bench! BTW, this stage and the next can be safely done indoors.
Final phase is to run the tank again but this time with just clean water to remove all the soap. Change the fluids in phase 2 and 3 often. I found that I could clean all 6 injectors in phase one without changing the petrol but phase 2 and 3 I cleaned 1 best and 2 at a stretch depending on how bad the injector was to start with.
Last step is to dry the parts. I used a parts dryer but essentially it is just a hair dryer or heat gun. The idea is to remove
ALL the moisture. It isn't dry until the part is hot and dry. By hot, I mean to the touch as a hair dryer would make it NOT as a blow torch would! You don't want it hot enough to anneal the metal.
Now all the usable parts are clean and we can start to measure and determine what will be going in the injector!
I know I said I wouldn't stop till I finished but The misses is kicking up a storm and its 1 am here. I will have to leave the juicy bit till tomorrow. so please feel free to comment as you wish, but I will withhold my responses until I have put my case forward in full and THEN I will defend my position.
Have a good night and Ill see ya tomorrow night. (I have injectors to install and an engine to start after 5 months of trials and tribulations so forgive my impatience!)
