Is this a valid way to test injector?

[Archie0979]

I have a Avensis 2.2 D4D and have been have injector problems. The car is laboured starting when cold and get some grey/white smoke. Once warmed up the car has full performance and no smoke. I am 95% certain the injector washers are gone as there is a puffing sound (very notable when cold) and there is a build up of pressure in the crankcase causing it to blow heavy out the breather and leave some oil in the intercooler pipe. It is going in tomorrow to get all 4 washers replaced and the mechanic is hoping that is the only cause of my problems but said he will try and test the injectors also. I have done a rough test by myself by disconnecting each injector power harness individually. When 1,3 and 4 are done, there is a noticeable drop in idle speed and is almost missing. But when I done this to number 2 there was absolutely no change in engine performance. It seems that the issue is now pointing to cylinder 2. My question is, could blow-by from a bad washer on injector 2 causing low compression  causing all the issues or would it be more likely a bad injector? Again I know the copper washers are a known problem and they have never been replaced and the car has done 137,000 miles and has all the classic symptoms of failing washers.

[Bomber209]

Archie Hi, I don't think the blow by would give you these problems as fuel should return to the low pressure side. It sounds like you've a sticking (closed) injector or a bad electrical connection to #2. A poor washer seal would allow air in as well. A rule of thumb is White smoke, to much air. Black smoke over fuelling (not enough air), you often get a puff of black smoke before the turbo kicks in when you floor it. 💨

[Archie0979]

It's funny you should say about white smoke. When driving normally I get no smoke but if I accelerate hard I get a small amount of white smoke. Once the car is up to temperature it runs fine and I have no loss of performance. The issues only show at start up and while cold. The main issues are a longer crank time and a rough idle. Once up to temperature the idle smooths out.

[Archie0979]

Got the car back this morning and it's finally fixed after the last 4 weeks of back and forth to the garage. The copper seal on no. 4 was completely gone (others were okay) unfortunately it must have been leaking a while as the injector was also dead. The bottom of it was bellowed and the needle point was all burnt out. Replaced all 4 seals and put in a re manufactured injector, re coded the injector and all seems fine now. Engine no longer breathing heavy, start's, idles and runs fine and also no oil leaking out of intercooler pipe now.