I installed a Edelbrock 1792 lift pump last week Friday. All seems good execpt:

In the mornings I will get a 0089 fuel pressure reg code. This started Saturday morning. I reset the CEL and drove Saturday all day, raced and drove around Sunday, no light. Monday on the way to work it came back on. If I drive around a bit, it goes away and the next morning it re-appears. It does not limp the truck and it seems to drive good. Idle seems normal with or without the light also.

I have done some searching and I am thinking maybe change my fuel filter and run some diesel additive. I am wondering if this problem is because of the lift pump I installed? Or maybe the pressue the pump is running at(12 psi factory setting) is too high?

Any toughts guys????

Update, it only comes on when the truck is at idle!

HELP!

it is fuel rail pressure to high. it only happens at idle probably because off idle you are using more fuel, and the lift pump is okay, at idle 12 psi is high. try backing that down most run the pumps around 3-6 psi. search about lift pumps i'm sure you'll find it.

OK, Saturday changed my fuel filter. The truck runs smoother, harder, etc. noticable difference it was due.

Checked my fuel pressure demand and actual with my tuner. Evrything looked good, no sudden drops or spikes at idle.

Ran all weekend, no problems. Started the truck this morning, went into the garage for something, came back out, CEL:mad:

So now what??? Should I turn the pressure down on my lift pump? I really cant think the FPRV is bad. The code started after the lift pump was installed!

I have an aftermarket lift pump and it measures 10psi at the test port.

That will set off the CEL in the mornings on my truck also.

After the fuel warms up past say 100f(as per the predator) the truck will not set off the CEL.

You could also run the truck in Tow/Haul mode in the mornings as the truck will warm up and it will not set off the CEL....at least in my truck(2004 LB7).

I am not exactly sure of the cause whether it is something in the design of the Fuel pressure regulator that is causing the problem...because supposedly others have noted the IP low pressure side can take up to 20psi.

My truck sometimes has lopey idle..and I have been meaning to swap the regulator out but have not got to it yet.

Others who have had the same problem have simply lowered the pressure to around 9psi or below and the problem goes away...or they have installed a demand lift pump where the pressure goes up to try to move more fuel at speed and the pressure is lower at idle.

I threw on a 0-100psi auto gauge fuel pressure gauge, started the truck and it read 18-19psi at idle?

I turned the pressure screw out 3/4 of the way and dropped the pressure to 12psi on the gauge. Revved the truck a bit and looked again, still at 12psi.

SO far so good. I may order a 0-20psi gauge for a more accurate reading but wither way it was too much. The minimum the pump will go is 6.5 psi which at 85gph(pump rating), would still be enough fuel I would think.