2011 Chevy Silverado 1500 Fuel Pressure Problem?

[bassmaster]

Does anyone know where the fuel pressure regulator is on a

2011 Chevy Silverado 1500 with the 4.8l V8? I ask this because I am experiencing

problems with my truck that lead me to thinking that the pressure regulator may

be bad. The truck is hard to start after it has sat for a while say overnight

or like 8 hours. Its seems it is worse when it is cold outside. The problem has

recently started occurring and has seemed to get worse. Once I go to crank the

car, it doesn’t crank the first time then the set cranking time is disabled so

you have to hold the key. The starter motor turns fine and then it finally

cranks then bogs down for a second at 200 rpm’s, then fires up to 1500 rpm’s

like it should. It idles rough for about 15 seconds before it smooth’s out. You

can see the antenna shake when it does that. Once it cranks you have to step on

the gas petal to keep it from stalling. If you try to put it in reverse quick

it will stall. If you give it gas while it is cranking it seems to crank

easier. After that it runs perfectly

fine. It does not do it when the engine is hot, nor does it idle rough when it

is hot. So that is what leads me to thinking that the pressure is leaking out

of the system because it acts as if there is no fuel there. I’ve had the

battery and starter checked so that eliminated that. I took it to the

dealership and they couldn’t figure out what was wrong. They hooked it up to their

diagnostic system and it couldn’t find anything wrong. No codes are showing up.

I let it set overnight there so a technician could crank it in the morning to

try to figure out the problem. They suggested that I have the throttle body

cleaned along with the fuel injectors and that might fix the problem, but they couldn’t

guarantee that. . They never checked anything with the fuel system. I guess

they didn’t think that was the cause? But it wasn’t doing it as bad then as it

is now. It didn’t stall then or not crank on the first try, just bog down when

they looked at it. If it were a sensor, I would think a code would show up. That’s

what makes me think there is something wrong with the fuel system. The truck doesn’t

act up once it cranks for the first time so I figured it wouldn’t be the fuel

pump. Is there any way of testing is the fuel pressure regulator is bad. Or do

these sound like symptoms of it. If so where is it located? I posed something a

couple weeks ago about it but this is it now. Here is a video of it having the

problem. At the end you can hear the engine finally crank and hear it “bog down.”

The first video is what it was doing when the dealer looked at it, and the

second is what it is doing now.

 

 

 

 

 

[gmtech4]

Fuel System Description

Fuel System Overview

The Fuel System is an electronic returnless on-demand design.
A returnless fuel system reduces the internal temperature of the
fuel tank by not returning hot fuel from the engine to the fuel
tank. Reducing the internal temperature of the fuel tank results in
lower evaporative emissions.

An electric turbine style fuel pump attaches to the fuel
sender assembly inside the fuel tank. The fuel pump supplies high
pressure fuel through the fuel filter and the fuel feed pipe to the
fuel injection system. The fuel pump provides fuel at a higher rate
of flow than is needed by the fuel injection system. The fuel pump
also supplies fuel to a venturi pump located on the bottom of the
fuel sender assembly. The function of the venturi pump is to fill
the fuel sender assembly reservoir. The fuel pump and sender
assembly contains a reverse flow check valve. The check valve
maintains fuel pressure in the fuel feed pipe and the fuel rail in
order to prevent long cranking

[SILVERADOSC540]

Second video are you pressing down the accelerator? Had a co-worker buy a used 2010 and was pressing the accelerator pedal to the floor when trying to start and that was happening. Took his foot off of the gas pedal to start and it was fine. Otherwise warranty should fix the problem... in time.

 

Edit: just noticed that I'm in the ask a tech section, not my place, my bad.

[Doug_Scott]

It sounds exactly like the gas pedal is being pressed down. I read somewhere on here about a service bulletin on the TPS. Does that service bulletin apply to this truck? Not unusual for dealer to not know of a service bulletin.

My truck is a 2010. I can just turn the key to start, and let go of it right away. Truck will continue to crank until it starts. I think it may have not started twice doing it that way. I have been recently pressing the brake pedal when starting the truck. Not for any real reason, but, it is the first pedal I have to push before I can take it our of park anyways.

[gmtech4]

It sounds exactly like the gas pedal is being pressed down. I read somewhere on here about a service bulletin on the TPS. Does that service bulletin apply to this truck? Not unusual for dealer to not know of a service bulletin.

My truck is a 2010. I can just turn the key to start, and let go of it right away. Truck will continue to crank until it starts. I think it may have not started twice doing it that way. I have been recently pressing the brake pedal when starting the truck. Not for any real reason, but, it is the first pedal I have to push before I can take it our of park anyways.

common practice at a dealer is to put a code number or a complaint into the search engine in GMs service information site ,,,,,that brings up several headings to check thru for TSBs or the code diagnostic or whatever your looking for ,,,,,,

 

i found this in 5 seconds

 

#09-06-04-015B: Information on Vehicles

Sitting Outside on Dealer Lots for Extended Periods of Time with Hard

Start or Crank/No Start Condition - (Nov 4, 2013)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Subject: Information on Vehicles Sitting Outside on Dealer Lots for Extended Periods of Time

with Hard Start or Crank/No Start Condition

Models: 2009-2014 GM Cars and Trucks

Attention: The Information in this bulletin applies only to unsold vehicles in dealer inventory

and does not apply to customer-owned vehicles that come in for service. DO NOT replace

the ECM for this condition.

 

 

This bulletin has been revised to add the 2012-2014 model years. Please discard Corporate

Bulletin Number 09-06-04-015A.

 

 

Some service department personnel may experience a hard start or a crank/no start

condition with any of the above vehicles if they were delivered in the late spring/summer/early

fall time period, and have remained in inventory for an extended period of time through

the winter. This condition is more noticeable in regions of the country that experience

cold climates. It may be caused by the vehicle's fuel tank containing a summer-blend

quantity of fuel in it that was more suitable to the warmer climate that existed when

it was delivered. This condition is known as a fuel blend/season mismatch.

 

In the U.S., summer-blend fuel is federally mandated for use in the June 1st to September

15th time frame. Some states, California for example, have enacted their own seasonal-blend

regulations that lengthen this time period. Canada has similar regulations for fuel

blends that are adjusted seasonally and geographically. Summer-blend fuel has a different

(lower) Reid vapor pressure (RVP) which contributes to it being more ecologically

friendly, by reducing the rate of evaporation. RVP is the standard used to measure

the vapor pressure of gasoline at 38°C (100°F).

 

Fuels with a greater RVP evaporate more easily than those with a lower RVP. The main

reason that summer-blend gasoline will not work well in the winter is due to its low

evaporation rate, which makes an engine difficult to start in cold ambient temperatures.

This is the reason that the hard start, no/start condition appears to go away when

the vehicle is brought inside the service garage and has had the opportunity to warm

up to ambient

temperature. However, the condition will repeat itself once the vehicle has been placed

back outside on the lot and has cooled back down to a cold ambient temperature.

 

If the above condition exhibits itself as explained, or is suspected because the vehicle

has been in inventory for an extended period of time, then refuel the vehicle with

enough fresh gasoline to start and run.

 

In order to prevent further occurrences, do not fill the fuel tank until the vehicle is ready for the Final Inspection & Preparation as indicated in the Pre-Delivery Inspection Form just prior to delivery of the vehicle to the customer.

 

If another cause for the crank/no start condition is suspected, then refer to Engine

Cranks But Does Not Run in SI.

[gmtech4]

Engine Cranks But Does Not Run

Diagnostic Instructions

• Perform the
  Diagnostic System Check - Vehicle
  prior to using this diagnostic procedure.
• Review
  Strategy Based Diagnosis
  for an overview of the diagnostic approach.
• 
  Diagnostic Procedure Instructions
  provides an overview of each diagnostic category.

Circuit/System Description

This Engine Cranks but Does Not Run diagnostic is an organized approach to identify
a condition which causes the engine to crank but does not continue to run. This diagnostic
directs the service technician to the appropriate system diagnosis.

Diagnostic Aids

Inspect for any of the following conditions:

• Insufficient fuel can cause a no start condition. Thoroughly inspect the fuel delivery
  system for sufficient fuel volume to the fuel injectors. Inspect the fuel supply components
  for partial blockage or restrictions.
• Fuel injectors with partially blocked and restricted nozzles, or a malfunctioning
  solenoid, can cause a no start condition.
• There may be fuel spray at the fuel injectors and the indicated fuel pressure may
  be correct, yet there may not be enough fuel to start the engine. If the fuel injectors
  and the injector circuit are OK and fuel spray is detected, the fuel injector ON time
  may be inadequate. If the engine control module (ECM) receives incorrect inputs from
  the various information sensors, the fuel delivered by the fuel injectors may be inadequate
  to start the engine. Observe all the engine data parameters with a scan tool and compare
  the values indicated with the expected values or the values from a known good vehicle.
• Observe the Engine Speed parameter while cranking the engine. The scan tool should
  indicate a steady 200–300 RPM while cranking. If erratic values such as sudden spikes
  in the engine speed are displayed, the engine reference signal is not stable enough
  for the engine to start and run properly.
• Inspect the engine for good secure electrical grounds.
• If the engine almost starts and then stalls, inspect for an open in the ground circuits
  of the CKP sensor and the camshaft position (CMP) sensor.
• Water or foreign material in the fuel can cause a no start or engine will not stay
  running condition. During freezing weather water can freeze inside the fuel system.
  The engine may start after 30 minutes in a heated repair shop. The malfunction may
  not recur until parked overnight in freezing temperatures. Extreme weather conditions
  can cause contaminated fuel to prevent the vehicle from starting.
• A vehicle that starts and runs after being brought to the repair shop for a no start
  condition may have an ignition system that is susceptible to moisture. Spray water
  on the ignition system components and the wiring in order to verify for an engine
  starting or will not stay running concern.
• When disconnecting electrical connectors or removing fuses and relays, always inspect
  electrical terminals for corrosion and for adequate terminal tension.
• Use the J-35616 GM-approved terminal test kit for any test that requires probing the underhood electrical center terminals, component
  wire harness terminals, or the controller wire harness terminals.

Reference Information
Schematic Reference

Engine Controls Schematics

Connector End View Reference

• 
  Component Connector End Views
• 
  Electrical Center Identification Views

Electrical Information Reference

• 
  Circuit Testing
• 
  Connector Repairs
• 
  Testing for Intermittent Conditions and Poor Connections
• 
  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References
for scan tool information

Special Tools

• CH-48027 Digital Pressure Gauge
• J-35616 GM-Approved Terminal Test Kit
• J-35616-A/BT-8637 Connector Test Adapter Kit
• J-43244 Relay Puller Pliers

Circuit/System Verification

Note:
This diagnostic assumes the following:

• The battery is completely charged. Refer to
  Battery Inspection/Test.
• The engine cranking speed is acceptable. Refer to
  Engine Cranks Slowly.
• There is adequate fuel in the fuel tank.

Note:
Additional DTCs may set when using the fuel pump output control.

Note:

• The fuel pump may need to be commanded ON several times in order to obtain the highest
  possible fuel pressure.
• The fuel pressure must be verified while the fuel pump is running.
• Do NOT start the engine for this test.

Note:
The fuel pressure must be verified after the fuel pump is turned OFF.

1. Engine cranking for 15 seconds, observe the DTC information with a scan tool. Verify
   that DTC P0117, P0118, P0122, P0123, P0201–P0208, P0222, P0223, P0300–P0308, P0335,
   P0336, P0351–P0358, P0562, P0563, P0601–P0604, P0606, P0607, P062F, P0633, P0685,
   P0690, P1631, P1682, or P2610 is not set.
   • If any DTCs are set, refer to
     Diagnostic Trouble Code (DTC) List - Vehicle.
2. Ignition ON, observe the security indicator. The security indicator should illuminate
   briefly, and then go out.
   • If the security indicator stays ON or is flashing, refer to
     Diagnostic Trouble Code (DTC) List - Vehicle, and diagnose any theft deterrent DTCs set as current. For more information concerning
     the Immobilizer system, refer to
     Immobilizer Description and Operation.
3. Engine cranking, observe the scan tool Engine Speed parameter. The scan tool should
   indicate an engine speed greater than 0 RPM.
   • If the engine speed is 0 RPM, refer to
     DTC P0335
     or
     DTC P0336
     for further diagnosis.
4. Test the ignition system for spark—Refer to
   Electronic Ignition System Diagnosis.
5. Ignition ON, command the fuel pump ON with a scan tool. The fuel pump should turn
   ON for 2-3 s and then turn OFF.
   • If the fuel pump does not turn ON, refer to
     Fuel Pump Electrical Circuit Diagnosis
     for further diagnosis.
6. Ignition OFF, install the CH-48027 digital pressure gauge. Refer to
   Fuel Pressure Gauge Installation and Removal.
7. Ignition ON, command the fuel pump ON with a scan tool. With the fuel pump running,
   verify the fuel pressure is between the appropriate value listed below:
   • 345–414 kPa (50–60 psi): w/o fuel pump control module:
   • 345–690 kPa (50–100 psi): w/ fuel pump control module:
   • If not within the specified range, refer to
     Fuel System Diagnosis.
8. After the fuel pump turns OFF, verify the pressure does not decrease greater than
   34 kPa (5 psi) in 1 minute.
   • If not within the specified range, refer to
     Fuel System Diagnosis.
9. Verify the following conditions do not exist:
   • Collapsed air intake duct to the throttle body
   • Restricted air filter element
   • Spark plugs for being fouled
   • A skewed manifold absolute pressure (MAP) sensor—Refer to
     DTC P0106.
   • A skewed engine coolant temperature (ECT) sensor—Refer to
     DTC P0116.
   • Exhaust system restricted—Refer to
     Restricted Exhaust.
   • Fuel contamination—Refer to
     Alcohol/Contaminants-in-Fuel Diagnosis.
   • Engine mechanical condition such as worn timing chain and gears or low compression—Refer
     to
     Symptoms - Engine Mechanical
     or
     Engine Compression Test.

Repair Instructions

Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.

[newdude]

Apparenty GM is aware of some sort of fuel pump issues on these trucks. We had a 2010 5.3 with 33000 miles get a pump. Guy had a hard start that was intermittent. Tech checked the fuel pressure and it was a slow build to normal psi. Then, it would be fine on the next test. If I recall it had to do with poor pressure priming from the pump or the pressure valve in the pump.

 

Also, the fuel pump flow control modules go bad on these trucks as well but those usually lead to no starts.

[Doug_Scott]

govtech4:

 

I take it you have some access to GM database, or service database, are these sites publically available to browse? Can you access them without using VPN, or remote access of some type?

 

Do all mechanics in a GM dealership also get access? Do they all get individual access credentials? I realize that no shop is going to either supply or allow a terminal or terminal connection at each workbench, so do they provide a room with terminals available to mechanics. I also understand that there is likely no single policy regarding this, each dealership will likely manage their own particular policy, and also that not all dealerships wish to be included in this century's technology. Sure wish they had this back in the 70's and 80's.

 

Back then the shop would get a monthly package of new service bulletins, new special tools if bulletins required them, and a package for each registered mechanic in the shop. Mechanics package was an up to date listing of the bulletins, that months new bulletins, binder to store them in once a year, and once a year there was also a "gift". Stuff like voltmeter, gold socket sets, screwdrivers, pliars, and other assorted hand tools engraved with whatever that program was called. Also would get a plaque if you attended new model release sessions. Still have all that stuff, only the voltmeter was of any real use, and after 33 years, it still works.

[gmtech4]

they are not public ,they are setup at the dealer level within their system,where programing etc can be done ...

 

i have no idea what VPN is

 

programing is wireless in the shop so a laptop on the bench/toolbox can be used and wireless to the veh for programing

 

it is way cool beans !!!!

 

govtech4:

 

I take it you have some access to GM database, or service database, are these sites publically available to browse? Can you access them without using VPN, or remote access of some type?

 

Do all mechanics in a GM dealership also get access? Do they all get individual access credentials? I realize that no shop is going to either supply or allow a terminal or terminal connection at each workbench, so do they provide a room with terminals available to mechanics. I also understand that there is likely no single policy regarding this, each dealership will likely manage their own particular policy, and also that not all dealerships wish to be included in this century's technology. Sure wish they had this back in the 70's and 80's.

 

Back then the shop would get a monthly package of new service bulletins, new special tools if bulletins required them, and a package for each registered mechanic in the shop. Mechanics package was an up to date listing of the bulletins, that months new bulletins, binder to store them in once a year, and once a year there was also a "gift". Stuff like voltmeter, gold socket sets, screwdrivers, pliars, and other assorted hand tools engraved with whatever that program was called. Also would get a plaque if you attended new model release sessions. Still have all that stuff, only the voltmeter was of any real use, and after 33 years, it still works.

GM has a tech guild and holds 5 exams through out the year to answer several questions/problems ,find bulletins etc ,,,,if ya get 'em all rite ,ya get Grand Master status and receive a collector plate and an updated certificate all framed and stuff ,,,,,i have 2 plates !!!! lol and a nice Bulova watch !!

[bassmaster]

If I took it back to the dealer, would they fix this problem under the warranty? They don’t need to hook it up to any diagnostic machine
again because they already did that. Would it fall under the powertrain warranty? Just wondering what is would cost to take it back again for them to look at it? I just don’t want to pay them again and they not find the problem.

[Doug_Scott]

If your truck is less than 36 months old, and under 60km(in Canada) it is covered under the bumper to bumper. Did you find the thread on here regarding the service bulletin on the TPS? What sort of relationship do you have with the dealer you purchased it from? A 2011 should not be far out of warranty, if the relationship with dealer is good, they will likely take care of you.

 

 

Found the post.. http://www.gm-trucks.com/forums/topic/155535-engine-power-reduced-service-traction-control-service-stabilitrak/?hl=%2Brecall+%2Btps&do=findComment&comment=1378540

[bassmaster]

Well it's got a little over 59,000 miles so that's out of the question. The problem is I bought it used from a ford dealership with 54,000 on it so I doubt they would do anything about it. Should I take it there or another Chevy dealership?

[Doug_Scott]

Well it's got a little over 59,000 miles so that's out of the question. The problem is I bought it used from a ford dealership with 54,000 on it so I doubt they would do anything about it. Should I take it there or another Chevy dealership?

 

Doubt the selling dealer will be of any use, unless you just purchased this truck in the last few months. One of the good things about ODBII is how the codes are the same between different manufactuters. Should not really matter to the mechanic (assuming mechanic is open minded) what make the ODBII system is bolted to. Troubleshooting should be the same flow chart for a Ford as it is for a GM. That being said, your issue does not throw a code, so asking a Ford mechanic to look into a drivabilithy issue on a GM may not work out in your favour.

 

When you go to start the truck, do you let go of the key right after the engine begins turning over? The trunk will normally crank over until it starts, up until the default crank time is met. I do not know what this limit is, but do know it is longer than 5 seconds, on my truck. On your next cold start (actually do this on all startups), with your right foot on the brake pedal (doing this ensures you are not accidentally resting your foot a bit harder than you think), turn key to On position for a few seconds(try waiting for fuel pump to stop pumping), then turn it to start position(without turning key off first), and release key after engine starts cranking. Instead of actually turning the key back, just open your fingers and let the key do what they want. Engine should start within seconds, if not in the first second. BTW, a "second" when cranking an engine is a hell of a lot loinger than you will believe.

[amc31b]

My truck is having this problem but it isnt as bad as Bassmaster's problem. It is just cranking a little weak and making the front of the truck shimmy for the first few seconds after starting. It only happens when it is cold outside and the truck has sat for more than 8 hours or so. I was initially blaming the the battery getting weak in the cold but the first TSB posted really sounds accurate. I am going to try running my fuel tank very low and filling up with fresh gas to see if that helps.

 

Govtech4- Thanks a bunch, Keep the helpful posts coming!

[gmtech4]

welcome as always !!