Bad injector?

[ambric]

I have a problem with my '99 idling and running rough. I pulled the coil plug wires one at a time and every one of them causes a big change to the idle except #3. I swapped coil and plug between cylinder 2 and 3 and the behavior didn't change (pulling #3 still causes no change to idle). Is a bad injector the most likely culprit? Is there an easy way to check it (I'm assuming pulling the rail means I'd need all new seals)? Thanks.

[Province]

I'd say either stethoscope or diy stethoscope on the problem injector while the car is running and listen for audible clicking noises which would tell you if it is good or not. If you don't have anything to use then I'd resort to just priming the fuel rail and then jumping 12v pulses to the injector and listen for its operation. Then from there you can conclude some things whether it be bad wiring, stuck injector, or clogged pintle caps/filter if the injector fires. In that last case, would be time to get a reseal kit ready.

[Rugbyfan]

I’ve pulled my fuel rail with the injectors still in place and had someone crank the car to watch the spray pattern. You will spray a few pulses of fuel so be smart and have the engine cold and outside. You won’t have to replace the seals but it is a convenient time to do the injector seals and pintle caps. When you reinstall the injectors use some sort of lubricant on the injector orings so the seals don’t tear when you reinstall.

[AJLM34A]

I thought I had a better angle on this setup I made for testing injectors to see if they are spraying properly. I spent about $25 in parts plus carb cleaner. Most of my injectors were only spraying out of 2-3 of the holes and the engine ran fine, or so I thought. I could never get them to spray properly no matter how much carb cleaner I ran through them. There is a FI service place somewhat close to where I live and they could only get 5 of the 6 injectors to flow properly. I had a spare set of 6 so I brought them some more to service.

There was a very noticeable difference in how the engine ran with properly serviced injectors.

Replacing the screen/filter and O-rings is a waste of time.

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