bigpaw

Should the pressure be more in the middle of the range of 38 to 44 psi?
The pressure holds at 44 psi for days after shutdown, and at startup (even below freezing) the starter cranks for less than a second and then the engine shakes like crazy as it starts really violently.
After it smooths out for a couple seconds it runs well at 1400 rpm (cold idle speed, then to about 950 rpm) when the outside temp is 30 degrees F. Has this kind of violent start either hot or cold.

At idle the fuel pressure is 37-38 psi with vacuum and 44 psi without.

The other problem it's having is a rough idle, could this be caused by high fuel pressure? What if my gauge is wrong and the pressure is actually 38-40 at idle, would this cause any idle/misfire problems or does that just happen with low fuel pressure?

scope103

If your fuel pressure is "too" high, you should just be running rich. Seems an unlikely cause of a "violent" start.

You might have one or two cylinders not firing on startup, and then after a few seconds they join the show. I'm not sure how to check that, but you could start by making sure all your injector connectors are nicely seated (so that you don't have an intermittent open).

desertwalker62

wow... interesting... i believe stock mechanical fuel pump for my '87 22r is only at 8psi, which i had to knock down to 3-4 with a regulator for my weber... what a giant difference!