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did a pressure test - injector

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Probationary Member
May 31, 2003
Well i pressurized my system with a vaccum leak tester, and had a very bad leak coming from one of the injectors. Now is there ever problems with the actual injector, or is it most likely the O-ring??(it looked like it was coming from where teh injector met the head).

Also, anyone know what size the O-rings are??
Those are the injector seals or one of the isolators is cracked. They aren't just O rings.. the Orings are on the top of the injector to seal them on the fuel side.
Old thread but this is how I test injectors.
To test the injectors you need a fuel pressure gauge and injector tester which will pulse the injector at pre-determined pulse width. You turn the key on until you reach max regulated pressure(making sure your pressure is the same on all cylinder when testing)
The injector tester connects to the battery and plugs directly onto the injector and you push the button and it will pulse the injector at a pre-determined pulse width for a programmed amount of time and then you compare the readings from cylinder to cylinder.
My tester is an OTC #3398 and has 3 pulse settings.
1 pulse of 500 ms, 50 pulses of 10 ms and 100 pulses of 5 ms
The tester sells for around $100.00.I have had mine for 5 years and my brother who works at a dealership uses the same one so I feel it is reliable.
The only way to truely clean injectors is to use a setup that connects directly to the fuel rail and the cleaner runs directly thru the injectors.The fuel system on the vehicle is disabled during the cleaning procedure.
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