fuel injector testing?

#1

I finally got around to my first arduino project after making smoke out of the first one. Just want to know how fuel injectors are normally tested. 325i injectors are suposed to be 154cc/min at 3 bar. I just wanted to know the test. Is that wide open for a minute or cycled for longer?

#2

So I made my own test and figured I would put a matched set in the racecar. I’m using a 500cc graduated cylinder so I figured 3 minutes should be good. I cycled each injector 10ms on and 10ms off for 18000 cycles for the test. That’s 3 minutes on and 3 minutes off total.

Of the first six on the spare intake my brother has had sitting around forever 5 patterned properly. Two of the three spare injectors patterned correctly but I didn’t get the matched set I wanted.

The first injector I tested ended up being the benchmark at 450cc. The replacements for the bad pattern injector that patterned well were only 405 and 406cc.

I drove up to my parents today and retrieved the fuel injector rail out of the racecar. Not a single one of them patterns properly.

I’m not sure that the pattern matters very much since they spray onto a closed intake valve anyway.

Anyway anyone who claims to dissassemble an injector is full of it. I dissassembled one with a large hammer today. Ultrasonic cleaning is the only thing that could be done beyond what I’ve done over the last few days. It would be easier to build a new injector than to rebuild an old one.

#3

Interesting, good work.

#4

I pulled the injectors off of the ix today. They also patterned badly so I gave up and bought a set of reman injectors. 26 something a piece plus a 10 dollar each core.

#5

i dont know if it’s of any interest but i remembered reading that a few years back :
http://www.northamptonmotorsport.com/default.asp?id=95