Is there a difference in output of fuel or spray patterns from different manufacturers on a standard injector? What recommendations have you got for standard injectors??
i cannot answer your question definitely, but i would think they would be made to suit the application, so KR and 9A injectors would be the same, they produce the BHP figures and have the same head/block configuration, so i would say they should be the same output/pattern. but i would like to add to your question and not start a new thread, my question - can you clean 16v standard injectors in an ultra sonic cleaning bath? i have a few injectors at home and a cleaning bath in work!
all kjet injectors that fit are the same spec/spray pattern. you can buy nice shiny new mercedes brass injectors off ebay which i would recommend there are 2 threads available on VW injectors though, you have kr and early 8v ones with a coarse thread, then the 9a and later 8v ones with a fine thread. plus 2 styles those with the top hat and those without. the merc injectors are coarse thread, without the top hat. all the top hat is for is the air shrouded injecton system, which doesnt really make any noticable difference I found. i had my kr lump running new merc injectors and old 9a top hat injectors and it ran the same either way
can you post the part number of those merc injectors and where can you buy them? I think I will buy new ones...
that was what i thought as well, but thought i would check. Cheers very interesting knowing about the merc injectors. great find RJ.
Hi guys The Air-Shrouding was only for the KR 1.8L JH engine. As you have already mentioned there are no noticeable performance differences but the air shrouded injectors and ancillaries which were different to those found on other 1.8, 1.7 litre Audi and VW engines (lower injector seals, different holder and insert) did improve the mixture formation particularly at idle. On the whole, Air-shrouded injectors reduces fuel consumption and emission. So basically, the air shrouding improves atomization within the chamber.
I have an '88 16V (KR) with standard Bosch 0 437 502 041 (VW 049 133 551A) air schrouded injectors and wouldn't change them to non-schrouded one's for the following reasons:
trouble is though is there any proper test results available to show if it really makes that much of a difference, to be worth the massive price hike from merc brass to vw steel? edit: acually is it me, or does that side cutout view just look like a normal kjet injector? the top hat on the air shrouded injectors we're talking about just clip on the outside of the injector they are not part of the injector assembly
That's exactly why I would like to keep air shrouded one's. As long as I do not see some test results which indicate that the air shrouding is worthless I prefer to respect and keep the original design of the system. The picture above is convincing enough for me. The side cut out view of the injector above is not related to the air shroud text by the way. It was simply a part of the general K-jet injector story. And indeed, the cut out is from a non air shrouded one. This one is air-shrouded:
I had Merc ones in mine, had the wur mod and control pressure setup on their dyno and it ran great, idled great and made good power. With the cis, the fuel is injected onto the back of valves that are shut most of the time..
So is there any way to clean injectors up? Will blowing compressed air through it clean the internal filter? What can go wrong with them as have a couple that where playing up in my race car
dont get me wrong, I'm not saying the air shrouded injection system is worthless. its just is it really so much better to be worth spending 2 or 3 or even more times the cost when replacing them over the cheaper merc ones? As I said I have tried both types on the same 1.8 16v engine, and I noticed no difference at all between them. So my personal oppinion would be no, its not worth spending loads more money for the steel air shrouded injectors over the mercedes brass units I'm not saying run out and bin the old injectors immediately, but if you need new ones then the merc units are fine. if air shrouded and non were the same price then I would say buy the shrouded! for cleaning I've heard you cant really do this but have a word with some of those injector refurbing places see what they say
I understand your point Cleaning isn't an option for these injectors as you can't open them like an electronic one. I've also been thinking how to open them whilst cleaing.. Logically you should open them from the needle side and blow the dirt out of the filter towards the pipe connection side, but how? Cleaning is not Always the solution by the way, sometimes the spring or needle(valve) is simply worn.
Kmi injection will test them for you for about 3+VAT per injection. Cannot be cleaned as such just washed through and tested.
