black944 turbo

Hey guys I am just curious on how to check injectors? If I can get some help, I would greatly appreciate it.

awilson40

Not a lot while on the car.
What kind of problems are you trying to track down?

Sam Lin

If they're on the car, it's easy - pull the fuel rail leaving the injectors clipped in it, get a large sheet of newspaper and lay it across the engine, and have someone crank the engine over once or twice while you point the rail and injectors at the paper. You'll be able to clearly see the spray pattern, see whether all are opening, and judge from the spot on the paper if one is partially clogged.

If they're off the car, then just send them to WitchHunter Performance.

Sam

Eyal 951

http://www.rceng.com/service.htm#INJECTOR

awilson40

Sam, Thats a good idea

black944 turbo

Thanks guys, I was told by someone that was folowing me that the car was smoking all the way to the interstate today 'black smoke'. I know that the car smokes a bit on start up and it smells of raw fuel, so I think that may be the problem. Thanks Eyal, I was going to send my injectors there but was hoping for a way of testing them first. So I think I may be able to test them that way and then send them off. I am thinking one of them is getting stuck open, partially at least.

toddk911

"I know that the car smokes a bit on start up and it smells of raw fuel"

I think a lot of us have this characteristic as well, so I wouldn't get to worried about it.

Sam Lin

Speak for yourself, it certainly isn't normal.

Sam

Zero10

Could also be a bad FPR.

black944 turbo

Brand new FPR and Dampener.

Billy W

Put a pressure gauge on the rail and see how fast the pressure drops when you turn off the car, that should let you know if one is leaking. I have had black smoke under full boost for about 4 years now it goes away after you flog the car hard once or twice. Does yours smoke all the time? Did yours smoke before the MAF?

black944 turbo

Hey Billy, my car smokes under full boost all the time. Nothing abnormal with that, but it smokes on start up and is steadily getting worse. It has been doing that off and on for a while now. I just tested my injectors with newspaper and it seems like the injector on Cylinder #4 is leaking. After testing them it dripped a few times all the rest stopped. Which leads me to believe under higher fuel pressures that this injector is probably leaking pretty bad. If not, oh well. I guess I will have to take it to Jim. Now if I can RC to e-mail me back that would be nice.

Danno

You can actually do a crude flow test as well. With the rail pulled off with the injectors still clipped in, put some clear plastic cups under each injector. Have someone crank the engine over for about 10-20 seconds. You can then see how much volume each injector delivers. This test assumes that the wiring is OK and in my experience, you're more likely have problems with the wiring than the injector itself. Most common is shorted wiring where it enters the connector (you'll have to cut off rubber boot to see this).

black944 turbo

Thanks Danno, all the injectors seemed to be firing ok. But I guess I could try it and see. Would they still fire ok? Because they all fired fine but again the one seemed to leak a tad.

Chris Prack

All the idea's concerning pulling the fuel rail to watch atomized fuel spray out of the injectors is great but for the love of God please remove the wiring from the coil or ground the coil wire properly if you are sure you know how to do this. I don't need to see the " Good news, bad news - I don't need to shave anymore but have third degree burns" thread.............