How i do PC injector\cylinder test ISX (hydrolic ones )

[ceff_by]

Here is my experience.

Its known issue that finding bad (well, not well doing injector) its a bit tricky with ISX.

Cylinder perfomance test doesnt do well in all cases, pass pas pass but there is obviously something wrong.

So what i`m doing first -- cutout test

1. one by one -- nothing.
2. 5 off, one left, 1-2 seconds its abt to die then reenable all. Test all all 6 in that way. Sometimes it can work pretty long time on 1 cylinder (5 cutted off) -- means injector(s) is leaking.
3. It sometimes help to locate leaking one if customer doesnt have\doesnt want to replace all of them -- do check valve leak test. Then immediatly after start run cylinder perfomance test. Sometimes it will show you for a short time "fail" on some cylinder(s).
4. to catch bad bank (fuel\timing solenoid) sometimes youll have to gently play with accelerator for a bit (up to 900 and drop back). In some cases it will show for a short period #pass pass pass fail fail fail# (On 870 -- there is "front bank" "rear bank" pass\fail) means rear bank is bad.

Its not 100% metodic but give you much more then single cutout, or if cyl perfomance shows nothing.

I think there is another way -- pull calibration and see injector responses. Didnt try that yet, want to see opinions.

[Rawze]

I have really never had problems helping someone find leaky or problematic injectors.

I simply perform a leak test on them BEFORE doing any cut-out tests, etc. and then do cut-out test only after you have verified you have no leaky injectors.





then followed by...

[un_yun]

I have a skip under load and boost. It passed the leaked down. I do not have insite yet. So I took a temp gun to the exhaust. All are 300 +/- 10 degrees. Except # 1 it runs around 240 degrees. Is sixty degrees enough to cause a heavy skip when loaded under a pull, but barely noticeable under light load. The skip seems to come on at high boost.