gonzo 6.2

iTrader: (8)

2010 silverado 6.2 flexfuel 15k mi.
negative fuel trims off the charts,hard starting cold,just put gauge on it,at idle 45 LBS fuel pressure,turn engine off pressure creeps to 58lbs in 4min.

fuel filter and regulator all part of fuel pump assembly?

local dealer can be wierd about mods.considering pulling headers.This issue is with modified tune and stock tune

Any ideas or next test?

gonzo 6.2

iTrader: (8)

Does the PCM control the FPR with the flexfueled vehicals?

Area47

to a degree it does. also has a variable voltage pump. take it to another dealership than your usual one.

gonzo 6.2

iTrader: (8)

Idle log,i have a driving log,tons of KR at cruise or light load.I tried to post it but to big,it see's -30 LTFT at times

it took no time to get headers off,cast iron goes back on AM before race starts ,fuel pressure gauge dropped to 35lbs after resting approx 5hrs.

next dealer ship is an hour away.that wierdness of the FP raising after engine shut off makes me think could it be filter plugged?

Im open to ideas,out of 12 new gm trucks since 1989 Ive had great luck and not had an issue this soon,sorta tempted to order FP just do it,Ive got little faith in dealer unless I personally know a tech

3heartsurfer

Really going to need a mod friendly dealer if your tuned. Hard if not impossible to hide the tuning time stamp in these ecu's.

Is it at 45 lbs when initially cranking?

gonzo 6.2

iTrader: (8)

good question,when i tossed gauge on today it shot to 58,seconds later I tapped throttle it went to 45psi,the starter spins like hell to get it to fire cold ,say 5-6 sec

gonzo 6.2

iTrader: (8)

here in my area ive seen mice chew wires and cause issues,today i seen a chunk of insulation laying on intake,no sign of turds everywhere,with both inner fender wells out,no sign on mice

smokeshow

iTrader: (16)

Is that all the mods it has is long tubes? Sounds like it just needs some traditional fueling changes... Reset your LTFTs to see if it starts any easier.

Fuel pressures are normal. These trucks have an FPCM instead of FPR. Fuel pressures are controlled in the tune under 'desired pressure' in the fuel settings. You can change them if you like...mine runs 58psi all the time.

gonzo 6.2

iTrader: (8)

FP readings today are with stock tune,45lbs at idle is normal?,hey anyone want to see driving log just PM me your email,happy to send it.(up to) 14* KR at lt throttle cruise slight tip in. could really shitty gas be doing this? Im not hearing any detination

smokeshow

iTrader: (16)

Yes, those fuel pressures are normal... Who did the tuning? 14 degrees KR is pretty crazy for so few mods. Something must be messed up in the fuel or spark.