304 question

[Brett Polwell]

My dad has a 73 304 in his Jeep. It runs great with more than enough power. The only thing wrong is that it seems to be leaking fuel into the oil. There is no noticeable blow by. Does this mean the rings are bad or is it just running to rich. It has the simple 2D Holley Projection with the digital computer and oxygens sensor.

[jeepsr4ever]

Sometimes this means a leaky fuel pump. I would replace that before I worried about rings. Brett the oil can handle very little gas contamination before it looses its weight and lubricity. Change out that fuel pump quick and possibly do a compression and spark test.

[Brett Polwell]

Would it be a fuel pump or fuel injector sinse it is fuel injected. Would it be leaking while its running or just sitting. There is no mechanical fuel pump on the motor anymore just a block off plate.

[jeepsr4ever]

Ahh. I am suspecting you have a dead cylinder that isnt firing.

[tufcj]

You need to do a fuel pressure check after it's been sitting a while. If the pressure has dropped to zero, then I'd suspect a leaky injector. Raw fuel will run down the manifold and into the cylinders. Is it hard to start after sitting a while?

Bob
tufcj

[Brett Polwell]

It runs great. It doesn't miss and it starts very easy. It sits for months at a time and starts the first time you hit the key. As far as fuel pressure it has an inline guage right before it goes into the throttle body. It carries 13 lbs while running. When you shut it off it bleeds down very slowly. It takes a few minutes to get to zero. the projection does have a fuel regulator and a return line to the tank.

[ironman_gq]

are't injection systems supposed to run at higher pressure than 13lbs? most of the systems i see run at close to 60psi

[tufcj]

Port injection systems do run 40-60 PSI. Older TBI systems run 14-16PSI. My Howell (modified 91-95 GM TBI) runs right at 16 PSI.

Bob
tufcj