Skip the auto shop - Our mechanics make house calls

Q: Truck not starting - 2002 Chevrolet Trailblazer

asked by on

Well it cut off on me while driving to get gas cause it was on empty so we relaced the fuel pump cause it wouldn't start but it wouldn't start after the fuel pump replacement but you can hear the pump come on and like I said the fuel filter is good and the gas is flowing thru the lines but it still won't start but the battery is weak can that have something to do with it not starting and also the computer had have me a code for the cam sensor and that has been replaced but still it won't start so what can it be cause I really need my truck it's my only transportation and I don't have money for high fixes

My car has 211125 miles.
My car has an automatic transmission.

Hi there, thanks for writing in about your 1992 Dodge Spirit. A slow cranking motor can definitely impede a motor from starting. First thing you need to do is connect a battery charger and get the cranking speed up. As for any other problems you might have, I wouldn’t make any assumptions. I recommend you check for spark, fuel, and injector pulse. Depending on what is missing will decide which diagnostic path to follow.

Spark problems will be coils, PCM, or a power supply issue.

Fuel pressure should be checked with a fuel pressure gauge. Your fuel pressure specification should be 48-52 psi with the key on. If you have released the fuel pressure at sometime, you may need to cycle the key once or twice to build the appropriate amount of pressure. If the pump is running, and it is new, you should have good fuel pressure.

You will need a noid light to check or injector pulse. A noid light is plugged into the injector connector in place of a single injector. Crank the motor and the noid light should flashed rapidly. You stated you had a cam sensor code. A cam sensor and a cranks sensor can cause the PCM not to fire the injectors and your noid light, or injector, will not fire. I would be checking these two sensors with the motor cranking using a scanner to watch the sensor waveforms.

Beyond the items stated above, your 4.2L motor has some camshaft chain issues as a result of bad chain tensioners. This can cause some strange driving issues and can often set cam sensor codes.

If you need help scoping this problem out, a certified technician from YourMechanic can come to your car’s location to diagnose the starting issue and let you know what needs repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I was just wondering why my airbag light is on?

Hi there. From the description you have provided, the problems described with the seat belt chime and airbag light are unrelated. The seat belt chime module may have failed long before the airbag light came on. The cut wires at...

Q: Cranks but won't start.

This may be a sign of a dirty or failing mass air flow sensor. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to being injected...

Q: I was driving my truck and it made this "poof" sound as if something blew. I lost everything--brakes, power steering, and it stalled

Hi, thanks for writing in. It is possible that the "poof" and exhaust smell (rotten gas smell?) both originated from the catalytic converter, and sulfur deposits in the converter. The engine may have backfired through the exhaust, setting off a...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...