ARGH 95 Injectors

[my65vette]

I have been told that my #3 injector sucks and the others are not in good shape on my 95 3.1 litre engine. They wanted over $1,000 to replace them. My son and I are a little insane and are thinking of tackling this on our own. Are we a little crazy for trying this or really stupid? How difficult is it?

[GTP Dad]

Changing the fuel injectors is not a hard job to do you just need to get a good manual to assist you. To replace the injectors on the 3.1 you will need to gain access to the fuel rail by removing the upper phlenum from the engine. I believe there are 8 bolts that hold it in place. Before you remove anything you will need to bleed the fuel system. The book indicates you should pull the fuel pump fuse and then start the car and run the car until it dies from lack of fuel. Make sure you disconnect the battery before beginning repairs. If your car has a theft deterrant system make sure to lock it out before disconnecting the battery. To get to the point of removing the phlenum you will need to disconnect the air cleaner assembly, the vacuum lines from the throttle valve along with the throttle cable. Disconnect the electrical connections from the TPS and any other connectors and lines connected to the throttle body and the phlenum. MAKE SURE YOU LABEL EVERYTHING SO YOU KNOW WHERE IT GOES WHEN YOU GO TO REINSTALL IT! You will also need to disconnect the alternator bracket, coil bracket and the map sensor and bracket.
Once you get everything removed you should be able to easily see the fuel rail. Disconnect the injector wires (label each one as to the location or you will have real problems at start-up) and then remove attached fuel line and return line. Then remove the four mounting bolts and gently pull the injectors and fuel rail from the engine one at a time. The entire assembly should come out together. Remove the clip that holds each injector to the fuel rail and remove the injector. Take the new injector and reinstall in reverse fashion. Make sure you use a new o-ring on the end of the injector and lubricate it with petroleum jelly. Lube the o-ring only not the injector tip. Once all the injectors are in place, reassemble in reverse fashion. Make sure you properly seat the injectors in their proper locations. Reassemble the phlenum, use new gaskets, and torque the bolts. It will take you three to four hours to do this job especially if you have never worked on this part of an engine before but you should be able to save several hundered dollars. You only need hand tools, nothing special is needed.

I recommend that you purchase a Haynes or Chiltons repair manual for your vehicle before you start. It will answer all the questions that you have and include additional steps that I may have forgotten. Good Luck!