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Tim's Auto Repair
Tim's Auto Repair, mechanic
Category: Chevy
Satisfied Customers: 12737
Experience:  Have owned a repair shop for 25 yrs.
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2002 S-10 4x4 4 door with a 4.3 vortec.

Resolved Question:

I have a 2002 S-10 4x4 4 door with a 4.3 vortec. And I have some questions about it
Submitted: 3 years ago.
Category: Chevy
Expert:  Tim's Auto Repair replied 3 years ago.

hi

this sounds as if you may have a weak fuel pump,[common problem with this vortec]..you need to check the fuel pressure,these must have no less than 60psi at all times..you also need to scan the computer for codes,i would think you are getting a p0300[missfire]code,,if you don't have an obd2 scanner,auto zone and most parts stores will scan it and give you the codes for free

thanks

 

ALL THE BONUS MONEY THAT I RECEIVE DURING THE MONTH OF JUNE WILL BE DONATED TO THE AMERICAN RED CROSS FOR TORNADO RELEIF IN THE MID WEST AND DEEP SOUTH

 

THANKS FOR YOUR SUPPORT

 

 

FUEL PRESSURE

 

Testing and Inspection

CIRCUIT DESCRIPTION
When you turn ON the ignition, the vehicle control module Vehicle Control Module (VCM) energizes the fuel pump relay which powers the fuel pump ON. The pump remains ON as long as the engine is cranking or running and the VCM receives reference pulses. If there are no reference pulses, the VCM shuts the fuel pump OFF within 2 seconds after the ignition was switched to the ON position or if the engine stops. The VCM also turns ON the fuel pump for 2 seconds when you turn OFF the ignition.

An electric fuel pump pumps the fuel through an in-line filter to the fuel meter body assembly. The pump attaches to the fuel level sender assembly inside of the fuel tank. The fuel pump provides fuel pressure above what is needed by the fuel injectors. The pressure regulator keeps the fuel available to the injectors at a regulated pressure. Unused fuel returns to the fuel tank by the fuel return pipe.

Diagnostic Chart (Part 1 Of 5)
Diagnostic Chart (Part 2 Of 5)
Diagnostic Chart (Part 3 Of 5)
Diagnostic Chart (Part 4 Of 5)
Diagnostic Chart (Part 5 Of 5)

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.

 

  1. When the ignition is ON and the fuel pump is running, the fuel pressure indicated by the fuel pressure gauge should read 414-455 kPa (60-66 psi ). The spring pressure inside the fuel pressure regulator controls the fuel pressure.
  2. A fuel system that drops more than 34 kPa (5 psi ) in 10 minutes has a leak in one or more of the following areas:
    • The fuel pump check valve
    • The fuel pump flex pipe
    • The valve or valve seat within the fuel pressure regulator
    • The fuel injectors
    • A fuel pipe
  1. A fuel system that drops more than 14 kPa (2 psi ) in 10 minutes after being relieved to 69 kPa (10 psi ) indicates a leaking fuel pump check valve.
  2. Fuel pressure that drops-off during acceleration, cruise or hard cornering may cause a lean condition. A lean condition can cause a loss of power, surging, or misfire. You can diagnose a lean condition using a scan tool. If an extremely lean condition occurs, the heated oxygen sensors will stop toggling. The heated oxygen sensor output voltages will drop below 300 mV . The fuel injector pulse width will increase. IMPORTANT: Make sure the fuel system is not operating in the Fuel Cut-Off Mode. This can cause false indications by the scan tool.
  3. When you open the throttle quickly, the manifold pressure increases (low vacuum). The fuel pressure regulator increases the fuel pressure as the engine vacuum drops in order to compensate for engine load.
  1. A rich condition may result from the fuel pressure being above 455 kPa (66 psi ). A rich condition may cause a DTC to set. Driveability conditions associated with rich conditions can include hard starting followed by black smoke and a strong sulfur smell in the exhaust.
  2. This test determines if the high fuel pressure is due to a restricted fuel return pipe or if the high fuel pressure is due to a faulty fuel pressure regulator.
  1. A lean condition may result from the fuel pressure being below 414 kPa (60 psi ). A lean condition may cause a DTC to set. Driveability conditions associated with lean conditions can include hard starting (when the engine is cold), hesitation, poor driveability, lack of power, surging, and misfiring. NOTE : Do not. allow the fuel pressure to exceed 517 kPa (75 psi ). Excessive pressure may damage the fuel pressure regulator.
  2. Restricting the fuel return pipe with the fuel pipe shut-off adapter causes the fuel pressure to rise above the regulated fuel pressure. Using a scan tool to pressurize the fuel system, the fuel pressure should rise above 455 kPa (66 psi ) as the valve on the fuel pipe shut-off adapter connected to the fuel return pipe becomes partially closed.
  1. If the injectors are not grounded, check the spark plug associated with a particular fuel injector for fouling or saturation in order to determine if that particular fuel injector is leaking. If checking the spark plug associated with a particular fuel injector for fouling or saturation does not determine that a particular fuel injector is leaking, use the following procedure:
  1. Remove the fuel meter body assembly. Refer to Fuel Meter Body Assembly Replacement
  2. Reinstall the engine compartment fuel feed and return pipes to the fuel meter body and the chassis fuel pipes. Refer to Fuel Hose/Pipes Replacement (Engine Compartment).
  3. Lift the fuel meter body assembly just enough to leave the fuel injector poppet nozzles in the ports.
  4. Pressurize the fuel system by using the scan tool fuel pump enable.
  5. Visually and physically inspect the fuel injector poppet nozzles for leaks.

 

ALL THE BONUS MONEY THAT I RECEIVE DURING THE MONTH OF JUNE WILL BE DONATED TO THE AMERICAN RED CROSS FOR TORNADO RELEIF IN THE MID WEST AND DEEP SOUTH

 

THANKS FOR YOUR SUPPORT

Customer: replied 3 years ago.
My entire question did not post, here is the remainder :

. After a couple of months of doing it about 1 out of 10 trips, the torque converter went out and spun a bearing in the transmission. I took it to a good mechanic who rebuilt the transmission. In about a month, the noise was back and after 20,000 miles on the new transmission, the new torque converter went out. I took it to a different guy thinking the first had missed something. The new guy rebuilt the transmission, and plugged it in to diagnostics. It showed only mass air flow out of range. That has been about a month ago, the noise is back. Is the mass air flow causing all this tranny trouble?

Expert:  Tim's Auto Repair replied 3 years ago.

no

the mass is not causing the trouble

tell me,when does it make this noise?does it make this noise sitting still in drive?

tell me all you can

thanks

 

Customer: replied 3 years ago.
yes, but also running up the road at times. It may run a thousand miles without doing it then do it every day off and on for a week. but when it does it, the transmission shifts different, even a little rough til it finally gives up it seems. I don't even pull my little alum. boat with it after trans. #1. sometimes it does it cold sometimes hot. I've tried pushing it and easing it neither which seems to have any difference. It doesn't affect Rpm as i have a tach but it sounds like a turbine engine when it does it. it even does it in OD. the gear doesn't seem to affect it either. I changed the catalytic converter which was a little clogged, and it didn't do it for a week so I claimed victory, but in a week it was back. I'm out of ideas. thanks for your mind buddy
Expert:  Tim's Auto Repair replied 3 years ago.

can you tell if the noise is coming from the front of the trans or near the rear?

will it whine,while sitting still?

Customer: replied 3 years ago.
no it doesn't whine sitting still. when the noise leaves, it fades out over a couple of seconds and then the engine sounds normal. I think the noise is in front. I can't tell for sure though. I have trouble getting it to do it setting still cold or hot. It usually starts a few miles up the road if its going to. My transmission man #2 went through transmission and transfer case with fine tooth comb replaced everything and still there.
Expert:  Tim's Auto Repair replied 3 years ago.

ok

this is a tough one......this sounds as if the rear planet may be worn just a little,and may have gotten missed by the transmission guys..if it is the rear planet,it will get worse over time..if it were the converter,it would whine in drive while sitting still

thanks

Please ACCEPT my answer so I can get credit for my work.i don't receive commission unless you do ..I'm not always going to be giving you good news,so please don't let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate.. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.if i have sent any diagrams,please print them.they will only stay on here for an hour or so.PLEASE ASK IF YOU NEED MORE HELP

 

ALL THE BONUS MONEY THAT I RECEIVE DURING THE MONTH OF JUNE WILL BE DONATED TO THE AMERICAN RED CROSS FOR TORNADO RELEIF IN THE MID WEST AND DEEP SOUTH

 

THANKS FOR YOUR SUPPORT

Tim's Auto Repair, mechanic
Category: Chevy
Satisfied Customers: 12737
Experience: Have owned a repair shop for 25 yrs.
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