FUEL RAIL PRESSURE DROP

[moridgerunner67]

FUEL RAIL PRESSURE DROP

Problem;
1997 Jeep Wrangler. 4.0 engine ,std trans.
Fuel pressure bleed back from 49 PSI to 30 PSI in 10 seconds after engine OFF.
Bleed back to 0 PSI after 4 minutes approx.
Idle pressure is 49 PSI
Takes a lot of extra crank time to restart engine due to no rail pressure.

This Jeep had a new fuel pump installed last summer to correct this problem but it did not help.

The fuel regulator is built in to the top of the fuel pump and there is no vacuum regulator as a lot of the Jeeps have.

We have put in a line check valve as we have done before on many Cherokee’s which cures the rail bleed back at engine shut OFF and cures the long crank time needed ( these Cherokee’s of course had a return line and a vacuum regulator in system. )

The problem here is that after the shut OFF of Wrangler engine. The engine will “heat sink” the engine and fuel system, which is normal, but the rail pressure will rise to 85 PSI and the fuel hoses are really stressed and in one case the line blew off. We did put premium type worm gear clamps on and new high pressure hose and tightened securely with out hose blow off. This not the cure for this problem since the fuel rails pressure increase is not good for the system.
Is there any alternate way to correct this problem as this man sure does not want to buy another fuel pump.

Tom Viets
SEND REPLY TO moridgerunner67@yahoo.com

[Junkpile]

I chased this on my 93 wrangler for 3 months. The fuel pump was the first thing I replaced. After somewhere in the neighborhood of $200 in other parts, and crappy tasks like removing and cleaning the injectors numerous times and blowing out the lines and resealing the tank and and and..... I finally,out of frustration, replaced the cheap fuel pump I had first bought with a factory replacement, and fixed the problem.