digitaldeath

hey guys , im new to this forum but have heard alot of good things about people being very knowledgeable here.

my truck is a 2004 suburban 1500 flex fuel 144,000 miles
throwing 2 code system too lean bank 1 & 2
ive done fuel filter replacement, going to clean the maf and throttle body plus run some bg44k in fuel system within the next few days
recently bought a soilport elm 327 obd2 works well with torque app

so my question here is what should i be looking for with the system too lean bank 1 & 2 codes and what should i be looking for on the obd2 scanner.

im new to the whole scanner bit and chevy, i had a vw jetta i used to work on and ill tell you what i love the ease of chevy and the room

thanks all and thanks to all who responds

kevinkpk

I'm thinking fuel pressure. Can you check it? I am not familiar with flex fuel, but this definatley points to fuel.

digitaldeath

I don't have a way to test it at the moment(no pressure tester). The truck has twice(past 6 weeks) not started when the the gas was under a quarter tank only to start after filling it past a quarter
Prolly should have added that before
Thanks

73shark

Welcome to the forum.

I agree that fuel pressure should be checked. A gauge runs about $40-$50.

digitaldeath

thanks for the welcome. lots of good info to be found here

any recommendations on these

actron pro tester kit(more fittings for throttle body injection)
actron standard kit
otc standard kit

thanks

kevinkpk

You just need to measure the fuel pressure at the engine.

digitaldeath

Picked up a cheapo from harbor freight
Ill get it tested and put up my fuel trims, long terms are looking very high

Thanks guys

digitaldeath

ok so my fuel pressure is 35psi at idle with minimal increase 2-4 psi when engine is revved to pretty much any rpm.
Shows 45psi when engine isn't started but then quickly drops to 40psi after a sec and holds
my long term fuel trims are 15-25% at idle and when engine warms up and driving they are around 9-11%
short terms seem to fluctuate normal

What's the common problem here
Fuel pump?
Pressure regulator?
or is it within specs, to my current knowledge im not within spec

digitaldeath

update

brought back gauge(had a feeling it was faulty)
retested and it reads 50psi with just ignition on ngine off
engine running at idle it reads 45 psi, when the vac line running to the pressure regulator is disconnected it jumps to 55psi

regulator is good
fuel pressure is in correct spec(so i guss pump is ok)
not so sure where to go from here though
any help would be good, thanks

kevinkpk

I am not sure (again) with flex fuel, however the pressure looks good. Have you tried regular gas or another fuel source? This still points to fuel to me anyway.