Injector failure/testing/cleaning

[Qdog]

I'm finally going to pull the plenum for the first time this weekend (wish me luck). Suddenly, the car developed a miss. I will ohm test the injectors, but if this does not show a bad one, is there a way to determine if one is bad (short of consult) ? The idle is shaky, and there is much shaking under load especially below about 2200 rpm, and higher rpm power is down. I will be replacing plugs, cleaning everything. I want to be confident that the injectors are okay before replacing the plenum. I want to bench clean them, but unsure of the best procedure & cleaning solvent. Can I safely apply 12V to an injector for several seconds to allow solvent flow ? Or should I just take them to a shop that can clean & flow test ? TIA

[demhaizar]

I had the same problem!, and have an easy way to find out which cylinder/s is(are) not firing.Look at the exhaust headers on each bank, the one (or more) that have unburned oil, grease dirt, etc is/are the injector/s that is/are malfunctioning. I caution you that hopefully this is the only problem, it worked for me. GOOD LUCK!

[DAEDALUS]

Removing the plugs should also give good clues as to which cylinder is missing. As far as applying 12V, I've wondered this too. I think the only risk is with overheating, which I doubt is much of a concern for only a few seconds at a time. Not certain though. I would personally try to keep contact for less than a second at a time. A bunch of quick taps of the terminals ought to be enough. You could even use the ignition system if you can get a spare harness and work close enough to the car.

[911/Q45]

Do a search on injectors, Daedalus has carefully shown all of us how to test the injectors with an ohmmeter without removing the plenum. If they check out electrically, then a rail flush is your best bet. Bench cleaning doesn't seem to be any more effective and it's a whole bunch harder.