Thursday, September 9, 2010

327 - Fuel Injection Diagnosis

This is a 1 minute video describing the basic function of the fuel delivery system on a fuel injection unit for a 1963 Corvette. This is a video so be sure to push the play button. In the previous post I indicated we had an assembly error that would have made the initial start-up of our 327 impossible. I've circled the area of concern in this photo. This connection is on the the fuel delivery side of the high pressure fuel pump and the connection is cross threaded and it's no where near tight. I removed the fuel meter to make the repair. The fitting is not only cross threaded and improperly tightened, the O-ring underneath was found cut in half. Identical O-rings were purchased, threads were cleaned up and the fitting and fuel meter were reinstalled. In this picture you can see the fitting is fully engaged to the fuel meter (it's directly below the bolt near the center of the picture). The fuel delivery system was then bench tested and it failed miserably. Something was still wrong.
This is a picture of our fitting and O-ring sitting on top of an enlarged photograph of an original GM fitting with it's original rubber seal. The seal is not an O-ring. Not only is the seal not an O-ring, take note that it isn't any wider than the brass flange that holds it in place. Our O-ring extends past the flange and this is the reason the O-ring was damaged. It was sheared when the fitting was tightened because it was too large to fit in its seat.
So, the fuel injection unit is temporarily on hold. I have located a supplier that has the proper viton "O-rings" and a set is on the way. While we wait I'll probably install the 1963 half shafts next. Thanks for watching.


  1. John, whats the guy that sold you the engine have to say about all these things?
    Jim p

  2. The good news is that the engine internals really do look awesome.
    Jim Q.

  3. I agree. The issues all seem to be external, but they also seem to be quite careless (two frost plugs, fuel / vacuum lines not connected and so on). I just hope he didn't get careless inside the engine. John, have you guys ever slowly turned the engine over and all that yet ? I would do that to insure you can get some oil pressure, confirm valve clearance and all that stuff........before you formally fire it.
    Just my thoughts. Jim p

  4. Yes, all that has been done. We have spun the engine by hand and we have spun it with the starter. No issues. We are being very careful to examine all aspects of this build. With exception of the items you mention on the FI unit, all looks good. I suspect when the motor was rebuilt they outsourced the FI unit to someone that wasn't fully familiar (or competent) with the work they were doing.