Injectors

need4speed · Post by **need4speed** » Mon Feb 20, 2012 3:38 pm

I have a full set of hotwire injectors of unkown mileage / condition. Though they look ok to the eye. Is it worth having them sent away to have them professionally cleaned and spray pattern tested? If so can anyone recommend someone? Thanks

ramon alban · Post by **ramon alban** » Mon Feb 20, 2012 9:48 pm

For very little money you can buy an ultrasonic cleaner

http://www.ebay.co.uk/sch/i.html?_nkw=u ... m270.l1313

That will take off all the external grime.

And still for not very much money you can buy a set of pintle caps and filter baskets to do a DIY maintenance job.

http://www.vintagemodelairplane.com/pag ... tor01.html

I'm told that so called professional cleaning can be as high as 96 quid per set of 8.

need4speed · Post by **need4speed** » Mon Feb 20, 2012 11:48 pm

That's some great information Ramon thanks. Will one of the little jewellery cleaners do the job. Do I just use the cleaner that comes with it?

ramon alban · Post by **ramon alban** » Tue Feb 21, 2012 11:30 am

My experience with ultrasonic cleaners goes back to my career in semiconductors when parts were cleaned using Deionised water, but just distilled water would be OK for home use.

Dunno what fluid comes with today's domestic U/S cleaners, but its probably water.

If you google ultrasonic cleaning you get oodles of guff.

One has to bear in mind the two key working parts of an injector,

a, the solenoid which operates the

b, pintle (or needle) which is essentially self cleaning.

So the U/S action is simply needed to knock off all the local hard crud around the business end and on the body.

Think of it as a substitute wire brush - which is actually what I used, with care.

The pintle caps do erode or get otherwise damaged over a long period of time and they are cheap to replace.

The filter baskets, likewise inexpensive, can't be removed without also removing and changing the inlet hose, but as you will have read, its eminently do-able.

I've done two sets of SD1 injectors in my home workshop but one does need to have access to a workbench and a suitable set of tools. Basic DIY/ engineering skills are also a help!

Quagmire · Post by **Quagmire** » Tue Feb 21, 2012 1:48 pm

I followed Ramons instructions on my flapper injectors replacing the caps and filters, and they all came out firing much more consistently aftewards, well worth a go.

I used distilled water and some kind of industrial degreaser stuff (non flammable) my dad had. After every session I blew them through at working pressure on the test rig with alcohol and just kept repeating until they were all the same.

When happy I then blew them through one final time with alcohol to remove all traces of water prior to storage.

ramon alban · Post by **ramon alban** » Tue Feb 21, 2012 4:03 pm

Quagmire wrote:I followed Ramons instructions on my flapper injectors replacing the caps and filters, and they all came out firing much more consistently aftewards, well worth a go.

I used distilled water and some kind of industrial degreaser stuff (non flammable) my dad had. After every session I blew them through at working pressure on the test rig with alcohol and just kept repeating until they were all the same.

When happy I then blew them through one final time with alcohol to remove all traces of water prior to storage.

Gosh Quaggers, that's the first feedback I had from someone following my web page on that subject.

With your permission I shall append your testimony to the web page.

So at least two of us set up a heath-robinson trickery machine to repair and test injectors.

Wonder if there are others out there who saved loadsa money with the same process?

Quagmire · Post by **Quagmire** » Wed Feb 22, 2012 1:19 pm

Ramon- of course you can quote me, thanks for taking the time to put the information out there in the first place!

Unfortunately I didnt take any pictures at the time, but I doubt that they will be last injectors we do - I will try to get some before and after shots in future.