Engine is a '00 5.3 with a newer reternless style rail. Running a LS Corvette fuel filter/pressure regulator and inline filter. Fuel pressure at rail is ~50 PSI key on engine off and engine at idle.

Just swapped the pump from a 190lph OE style Jeep pump to a TRE 255lph pump with no change.

I had bleed off of about 1 PSI per 3 seconds prior to pump change and found a leaking fitting that was resealed. Now bleed off is about 1 PSI every minute down to about ~40 PSI then it holds pretty steady.

I have a new filter/regulator combo on the way, is there anything else I should be checking? Engine running wise starts right up and idles fine, but under load by lugging, it will stutter and hesitate.

 

assuming this is in a jeep wrangler? honestly you dont need that vette regulator/filter the stock Jeep regulator will supply all the fuel pressure you need... Ive had my swap done now for well over 2 yrs using the jeeps regulator, I just scaled the injectors for 50 base vs 58

im not a fan of the vette regulator idea many use, also many use the junk version...there are only 2 vette regulators that are worth a damn a actual GM one and a WIX all others are junk

 

Is the bleed off due to the prime pulse? Mine drops a little when I key on and let it sit for a min.

 

Its a '97 Wrangler, I did the swap 4 years ago and just started having fuel issues recently. The stock regulator is rated at 45 PSI and its long gone since the swap.

 

Bleed off happens with key off, so wouldn't be anything with prime pulse as PCM doesn't have power.

 

Also, scaling the injectors to 50 PSI in my case will drop them to 23 lb/hr and run at over 80% duty cycle. So that doesn't sound ideal.

 

up to 85% duty cycle is perfectly fine and my jeep has 50 base with its 2000 regulator


if pressure is dropping swap the filter regulator...remember its a filter first


also the injectors will only be at 80% under high rpms and full load


even 45 base which is lower then what most claim is perfectly fine for fuel pressure

 

If a new filter/regulator dosen't bring the pressure back up to 58 I'll look at modifying the tune to match actual rail pressure and flow rate.

 

Just checked power supply to pump, key on engine off its at 12.39 VDC, was thinking if there was voltage drop the pump may have less output.

 

Those filters get dirty just like any other fuel filter