Topher306

Just installed our 306 crate motor last weekend. It idles pretty well around 700-1000 rpm. But when I take it out, most times when I let off the accelerator, weather it's to slow to a stop or even cruising at speed, the car just shuts off. The red battery amp light will come on, and I'll have to restart the car. Usually it just starts right back up, but it does it repeatedly. Any ideas on causes?

craig71springsport

Sounds like you have a loose wire possibly. Make sure it's all tightened up. Either that or it's dying for fuel or air. Does it just quick cut out or sputter to a stop?

Topher306

Just a quick cut, usually I don't even know it's dead until I try to turn the wheel and the power steering is gone.

mattdel

Releasing the throttle will cause the FPR to regain vacuum and lower the fuel pressure, if this wasn't happening the vehicle would stall from having increased pressure @ idle.

But, like already said, usually things of this nature tend to be electronic in nature.

Topher306

I had kind of been thinking electrical, but wasn't sure where to start with it. With what you were saying about the pressure at idle from the FPR, would that be suggesting the FPR possibly not working?

mattdel

Right. Just a theory, but plausible. Not too many things can cause the engine to die completely from just releasing the throttle. Obviously spark or fuel related.

Topher306

What would be the easiest way to test that theory?

mattdel

Rent a pressure tester from autozone and hook it up.

Topher306

In the interest of time we had it checked out, turns out there was a bad hose on the intake manifold causing a vacuum leak. Got it replaced as well as fiddling with the timing and TPS and now it runs great