5.0 SB Ford with Edelbrock performer heads and an Edelbrock Victor Jr intake (modified by Mass Flow - injector bungs welded in for EFI). Engine has about 2500 miles on it. I think the engine was first assembled with a carb, and the EFI intake installed later. It had 1500 miles on it when I bought the car.
I have been having a poor idle when cold, and I have been sorting out the EFI. However the problem was getting worse not better. I noticed that the fuel pressure was unstable when cold, and the fuel pressure regulator varies based on manifold vacuum. I threw a vaccum gauge on it and started it up cold. The vacuum was all over the map and dropping to zero. Vacuum was random, that is there is no pattern like a certain cylinder causing a drop. The vacuum drop leads the rpm drop. Once the engine was warm , the vacuum was steady, and the idle was steady as well (which is why I didn't find it earlier). Additionally my oldest son was ridding with me Sat. and said he thought he heard the squeel of a vacuum leak at a certain rpm.
My first thought was that if the leak is mostly sealed up when warm then it is likely do to aluminum heads and intake expanding. So I checked the intake bolts. With torque wrench set at 16 ft-lb, I got about a 1/4 turn per bolt. I pulled the throttle body and you can definately see where it has been sucking in
oil. No water has leaked into the
oil.
So here are my questions:
1) Should I put it together and see if this fixes it, or should I pull the intake and replace the gaskets? I'm leaning toward giving it a whirl.
2) I would like to clean the oily mess up inside my intake, ports, valves. It's a single plane so it is open to the valves (end cylinders are curved enough you cannot see the valves). Carb cleaner would clean it, but I'm concerned about spraying that much into the cylinders and washing all the
oil away from the rings. How best to clean this up?
Intake bolts loose
Threaded Mode
