MFI injector testor/cleaner

[BHerrmann]

I'd be glad to clean injectors for you guys, I'd just like to get a better feel for the pressure gauge and how it's supposed to work. Seems like it would be nice to know if the injector operated at the correct pressure, shut off when it was supposed to etc.
I assume that's what the gauge is for?? Any help?

Bruce

[rvdv]

This should really help you out Bruce:

http://www.drivewerks.com/techarticl...ctor_Maint.pdf


You will notice that the opening pressure is 15 - 18 bar for the mechanical injectors, whereas the CIS injectors are only about 3 bar.

Rudy

[pwd72s]

Great post Rudy. Obvious that this unit is for testing injectors only...designed for use with a NON explosive fluid.

[BHerrmann]

Thanks Rudy, good info. I took my injectors out today and filled the reservoir with Techron and checked my spray pattern. It worked well and I could easily see the pattern and pump quite a bit of cleaner through the injectors. It does seem that this unit is for checking but I can't see why it would not offer cleaining benefits as well. I don't know any other way to work a solvent though the injector. I also have an ultrasonic cleaning unit (retired from my Dental office) which I use to soak the injectors.
It also seems to offer some benefit.
I wonder what the real failure rate of these mechanical injetors is.
I guess the spring inside could go bad or something get caught in the nozzle and keep the tip open allowing fuel to come out all the time....

Bruce

[rvdv]

The injection pump pumps the fuel under pressure to each injector, as soon as the pressure in the line goes above the 15-18 bar the injector opens and lets the fuel pass through. This is done by calibrated springs inside the injector body. Over a period of time the springs will weaken and open the valve at a lower pressure, as a result the fuel timing and duration will not be correct.

Rudy

[BHerrmann]

So, I figure the best way to make use of this thing is to get a new injector right out of the box and compare it's opening pressure and spray pattern to the used ones so that's what I did. When it arrives, I'll test it and then compare it to used ones and see
what it's like. It should be helpful in determining if the spring allows the injector to open at a point close to the new one.
We'll see.

Bruce

[BHerrmann]

OK, thanks to all for the info, in looking at this testor it's obvious it was designed for CIS testing. So, I figured the only real difference is the pressure gauge itself as the injectors use the same size threads. I found a guage that reads up to 25 bar and fitted it to the testor. Now I can run the pressure up to 15bar or so and hold it, watch for leaks and then push it up to 18-20 and check the spray pattern. I'm currently using the Techron I mentioned earlier but other am looking for Varsol to try next.
I also have an ultrasonic cleaner (snagged from my office) and am soaking the injectors in it.
The new injector pattern differed very little from the used ones so I suspect they are probably still serviceable.

Bruce