944/951guy

Anyone know of a DIY for Fuel injector replacement?
My Targa is smoking like a train and I found it is spitting out fuel from one of the cylinders so I believe it is a injector stuck open.
Want to tackle this preferably without pulling the engine if possible.

Mike J

Not sure if a DIY is needed - its pretty easy. You need to remove what's in the way (airbox, ventilation fan), release the pressure on the fuel system or just let it sit for a few hours to allow the check valve to bleed off. Pull the DME relay to make sure you do not have fuel everywhere, and I would disconnect the right hand fuel rail feed and drain the line as best as possible. Have rags ready since its almost impossible to do this without leaking gas. Put out that cigarette. Remove the fuel rails from the engine, which will come up with the injectors, and pull the injectors off the rail by pulling the clip that locks the injector to the rail, and pulling of the injector itself.

Have them all checked then reverse the process. When starting up double check for leaks, sometimes the injectors do not like to seat in the rail, especially if you have replaced the O rings.

Cheers,

Mike

Ed Hughes

Pretty straight forward as Mike notes. I pulled mine without fully removing the rails, FWIW.

IainM

How did you find out it was spitting out fuel? Did the cat get red hot?

scarey

944/951guy

Sounds straight forward.
How does pulling the dme relay effect fuel spilage?

Car smoked like a train and I thought it might be a worn valve guide. I pulled the plugs and it is pouring out.

Quadcammer

I didn't mess around with the dme and not that much fuel came out. A few rags will more than cover it.

Very easy diy actually.

You may be able to save the injector with a good cleaning.

944/951guy

But how does it effect it anyhow? I mean fuel spilling if not pulling the dme replay when the car is completely shut off?

Quadcammer

the fuel system maintains pressure in the rails for quick and easy starts.

The idea being that if you pull the dme, the pump will not deliver fuel. You pull the dme, crank the car, expelling the fuel in the rail. With the pump not running, it cannot pressurize and you end up with little fuel in the rails.

You can just use the schraeder valve to reduce the pressure, but that doesn't eliminate the fuel in the rail.

944/951guy

Ahhhh, So if I pull the DME relay and crank the car the fuel in the rails will be gone. I think I got it....

JasonAndreas

You can also start the engine and just remove the fuel pump fuse. The engine will stall and most of the fuel in the lines will be gone.

nkcrichton

Hey does anyone have fuel injectors for my car, 1996 993 C4, thanks Nick.

IXLR8

Possible but why not check to see if the injector signal isn't low all the time. If it is, your injector will stay open. One lead (red/white) is hot all the time; the other lead is pulsed low to turn it on.

gtroth

I disconnect the positive battery terminal whenever I open a fuel system so I can't accidentally make a spark somehow.
And I put the fire extinguisher within reach.

Think about sending the injectors to Witchhunter