DuluthSVO

All,

I have a '92 4Runner with a 3.0L that seems to have an internal fuel system leak. Symptoms are VERY hard starting unless allowed to sit overnight, extremely cold air to help lean out the cylinder mixture (below 0 degrees F), or 1/2 throttle to induce more air to the mixture.

What is the easiest way to tap into the system to measure fuel pressure and make sure that the fuel pressure isn't bleeding off past the injectors. I'm use to doing this thru a schrader valve typically located on the fuel injector rail.....but none to be found on this vehicle.

Thanks for your help. DuluthSVO

eric-the-red

There is no built in vavle for testing pressure. You have to temporarily install a guage. My FSM says to remove a bolt which looks to be on the front end of the fuel rail below the pressure regulator.

abecedarian

you could install a tee between the regulator and rail and attach the gauge there and install a plug when the gauge isn't connected.

your issue though could be the cold start injector dribbling

Jay351

X2. Unplug the CSI and see how it runs. I have mine unplugged currently. How do you test the CSI anyways? I tested with an ohm meter and it had no resistance...

abecedarian

the CSI has very low resistance, 2-4 ohms IIRC, so you'd need to use the appropriate scale on the meter. But it should only operate when cranking the engine: should stop when you release the ignition key after starting.
If it continues spraying (but doesn't when unplugged) there is probably something wrong with the wiring causing the time switch to have voltage when it shouldn't.

DuluthSVO

Thanks to all of those who helped on this one. It was indeed the cold start injector pissing fuel at all times. I was able to cycle, while off the vehicle, with a battery and clean it with compressed air and later with carb cleaner. Thorough topend cleaning with SeaFoam....and better then new! Thanks again.