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My name is Ben and I'm your guru, i.e., mentor, an influential teacher
or popular expert: a management guru. - origin from Sanskrit, 'weighty,
grave', for today.
As you evaluate my advice and suggestions, there are a few things you must keep in mind:
• I did not diagnose your problem and am therefore only able to
evaluate what you tell me. For example, if you ask me a fuse location,
that doesn't mean that I can tell you the reason why the fuse blew.
• A thorough diagnostic approach involves the use of technical
equipment, such as voltage meters. scanning equipment and other
• Lastly, fixing one problem can very easily reveal a problem with
something that you might consider unrelated. However, you must keep in
mind that I can only evaluate and suggest based on the information that
Vehicle won't start
Your description of the problem:
2001 Toyota 4Runner (150K miles) with new battery will not crank or
start. It will start after charging the battery. I can see the lights
dimming as the car runs.
Late model vehicles are highly computer controlled to
reduce emissions, maximize fuel economy and improve consumer comfort.
The various control systems in vehicles are interrelated and controlled
by multiple computers that constantly monitor vehicle performance
through a myriad of sensors located throughout the vehicle. Based on
information received, the computers adjust the vehicle performance
through a series of valves, switches and motors. You must use a scanner
to unlock the information stored in your car's computer. Your 4Runner is
OBD II compliant.
A Scan Tool can be used to read and erase trouble codes, display, record
and play back LIVE diagnostic data and perform other tests allowed by
the vehicle maker. Scan tools that cover vehicles 1982 to present are
available at your local auto supply dealer.
You don't indicate any diagnostic tests to date. A dealer or your local
mechanic will charge $100-$200 to perform a diagnostic scan. However,
AutoZone will provide a thorough scan for FREE.
Anyone who tells you that a modern vehicle can be diagnosed without a
scanner with the problems you have set forth is merely guessing. You car
has a computer and memory and probably knows exactly what the problem
is. That on-board computer is just waiting for you to ask, "What's
wrong". Some of the suggestions cited below may require the use of a
code scanner or a code reader.
This is how your problem is solved in my shop. Out of the box, I'd say
that you have a problem with the fuel management system or one of the
system sensors that is causing the on-board computer to make adjustments
as best it can. However, there's a good chance that it's something
simple and inexpensive like a camshaft position sensor or a bad fuel
This is where you'll start.
Moderately Challenging (AutoZone will loan you the instrumentation FREE of charge)
Start with the pre-check:
Do a Thorough Visual Inspection
Do a thorough visual and "hands-on" underhood inspection before starting
any diagnostic procedure! You can find the cause of many problems by
just looking, thereby saving yourself a lot of time.
• Has the vehicle been serviced
recently? Sometimes things get
reconnected in the wrong place, or
not at all.
• Don't take shortcuts. Inspect hoses
and wiring which may be difficult to
see due to location.
• Inspect the air cleaner and
ductwork for defects.
• Check sensors and actuators for
• Inspect ignition wires for:
- Damaged terminals.
- Split or cracked spark plug boots
- Splits, cuts or breaks in the ignition
wires and insulation.
• Inspect all vacuum hoses for:
- Correct routing. Refer to vehicle
service manual, or Vehicle Emission
decal located in the engine compartment.
- Pinches and kinks.
- Splits, cuts or breaks.
• Inspect wiring for:
- Contact with sharp edges.
- Contact with hot surfaces, such as
- Pinched, burned or chafed insulation.
- Proper routing and connections.
• Check electrical connectors for:
- Corrosion on pins.
- Bent or damaged pins.
- Contacts not properly seated in
- Bad wire crimps to terminals
Instructions: Check the entire fuel delivery system.
- Relieve system pressure. Disconnect the
negative battery cable and loosen the gas cap to let pressure drain from
the system. Attach a dual tube pressure gauge to the test port and
drain fuel into an approved container.
- Disconnect the fuel pressure sensor vacuum
hose. Check for fuel in the line. If there is fuel present in the line,
the fuel delivery problem is likely caused by a faulty fuel pump
pressure regulator. If there is no fuel in the line, reattach the vacuum
hose and continue with the fuel delivery diagnostic.
- Twist off the fuel pressure test port cap and
attach a pressure gauge to the fuel pressure valve if one is not already
connected. Reconnect the negative battery cable and turn the key to the
first position. Do not start the engine.
- Check the pressure gauge. It needs to register
between 45 and 48 psi. Start the engine and let it idle. Check the
gauge again. It needs to register approximately 46 psi. Leave the engine
on and remove the vacuum hose. Check the gauge one last time. It needs
to register approximately 50 psi. Pressure that's too high indicates a
malfunctioning pressure regulator. Low pressure indicates a clogged fuel
filter or a broken fuel pump that needs to be replaced.
- Try to start the engine. If it starts, cut the engine off, relieve system pressure again and remove the negative battery cable.
- If the engine didn't start, remove the
negative battery cable. Clean the fuel filter inlet with compressed air
to remove any dirt that might come loose and contaminate the fuel supply
as you remove the fuel filter. Pull the filter out at the male filter
fitting and disconnect the remaining connections to the filter. Remove
- Examine the filter for clogs and replace it if
necessary. If there are no clogs, the fuel delivery problem is probably
caused by a breakdown in the fuel pump itself.
DO NOT RUN OUT AND BUY ANYTHING YET! This was only the opening act.
All of the above systems are monitored by an on-board computer. A
diagnostic scan retrieves any inform related to the malfunctioning parts
and tells you precisely what is wrong. Perform the scan diagnostic now.
Start the car and perform another scan. The reason we rescan and repair
non-related codes after the engine is running is because sometime false
codes can be triggered by the engine not running. Once the engine is
running again the code present might cycle and turn itself off. You
might say "if the engine doesn't run shouldn't it have a trouble code?"
Sometimes conditions occur that will not be detected by the computer,
e.g.,if the fuel pump fails the computer cannot detect the failure, so
the engine doesn't start and the computer thinks everything is okay with
If you have trouble using the code scanner or interpreting the codes
click on the following link and use my access code (carrepair): Free Automotive Repair information for Users of a Code Scanner
I know that the above is wordy but I wanted to do more than just tell you that your problem is complex.
All the best,