Alright folks,

I've got 2 fuel injectors that seem to be faulty or not working properly, as in, I feel no pulse when i touch them with my fingers, and there's very little sound coming from them when i listen to them with an automotive stethoscope.

A couple days ago I was going to have my fuel injectors cleaned while still on the car. They basically unhook your fuel "Feed" and "Return" lines, unhook the fuel pump, and let the car run off of a mix of gas and cleaning detergent that's ran through the schrader valve till it kills itself. The container with the gas/detergent has high pressure air pushing the mixture into the motor just like the fuel pump would. This is how it was supposed to work anyways..

What happened, was that the car would not run off of the cleaning mixture, I would say that there's probably around 35 ounces of liquid in the container, so it was a fairly decent amount..

The car wouldn't even fire up at all when trying to run on this stuff, i had spark and everything but no luck..

We opened the container with the mixture in it and it was all gone... around 35 ounces of liquid had been pushed into my motor without even firing up

We tried this process 2 more times and still no luck...

Why would the cleaner be getting pushed into my motor without it even trying to fire up?

My only guess is that the mixture is getting forced through the faulty injectors?

Any ideas?

 

Check the electrical resistance of the injectors. If open, you know they are electrically dead.

If resistance checks out, get a "noid" light so you can verify the injectors are getting the electrical pulse.

The cleaner was probably pushed through the regulator return into the tank.

 

The fuel lines were completely unhooked, there was no way for the cleaner to get into the tank....

 

is that new paint? i like

 

Were they unhooked AND PLUGGED? If not, you just sprayed everything out on the ground somewhere.

I have that setup and I've never unhooked the lines. Just deactivated the fuel pump electrically, popped the vacuum line off the regulator and hooked up the can. Can supplies about 36 PSI, regulator doesn't open until about 42 with the vacuum line unhooked so nothing goes down the return line unless the regulator is bad. Check valve in the fuel pump keeps it from back-feeding into the tank that way (again, unless it's bad too).

 

So there's no way for the detergent to back feed into the tank even with the fuel lines still connected??

Hmm, we had both the fuel lines unhooked but nothing plugged, and nothing came out when we tried this??

So all we do is unplug the fuel pump, unplug the vacuum line from the regulator and hook up the can containing the cleaning mix, then bump up the pressure to around 43, then start the car?

If that's all it is then hot damn lol

 

Was the can empty when you started? I mean, a quart of cleaner had to go somewhere! If it dumped straight into the motor you would start to wonder how it didn't hydro-lock a cylinder or two (check your oil for "fuel" contamination!).

To check if your fuel system holds pressure, hook the lines up like normal and run the engine for a few seconds. Wait a minute or so and push the stem on the schrader valve. It it's holding pressure fuel should spray out of it with considerable force for a fraction of a second, bleeding off the pressure in the lines. If it's got no residual pressure then something's leaking down somewhere.

Yes, I do these kinda "cheap-o" fuel injection cleaning treatments from time to time with my kit and I've never unhooked any lines. Did it just like I said, above. When they seem to make the biggest difference is on a car that's been sitting for a while unused and the injectors get gummed up. On cars that are run regularly a clogged injector is actually pretty rare.