Losing power and shutting off while driving

CWINE84

MEMBER
1997 CHEVROLET 1500
5.7L
V6
2WD
AUTOMATIC
230,000 MILES

I'm having a issue with my truck, while I’m driving it will lose power and shut off, I changed the fuel pump relay, fuel pump, and fuel filter thinking that was the problem. Until I was driving, and I heard a loud boom I realize my muffler had bust wide up causing the truck to become loud. I checked the codes, and o2 sensors and crankshaft position sensor code came up. I changed them and I’m still having a problem with it shutting off. Any ideas you think could be the problem? Thanks

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Hi,

If you had a backfire that bad, we likely have a fuel-related concern. That doesn't mean the fuel pump, but rather an air/fuel mixture issue.

Can you provide me with the trouble codes you found? Also, have you checked the catalytic converters to see if there is one that may have loose internal components causing issues?

Here is a link that explains symptoms related to a faulty catalytic converter. See if any mirror what you experience.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

Also, are there any odd odors noticed or sounds? Does this only happen when the engine is hot? Does it restart right away if it stalls when hot? Take a look through this link as well. It covers the common symptoms related to a faulty crankshaft position sensor. Let me know if it seems to identify the issues you experience.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

Let me know.

Joe

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Tuesday, December 21st, 2021 AT 5:19 PM

CWINE84

MEMBER
8 POSTS

Thanks for your response. The codes that came up were P0146, P0141, P0339, P0144. I’ve changed the sensors, but I haven’t changed the crankshaft sensor. When it stalls it’s usually sometimes early in the am or after running for a while. Once it stalls it might crank back up on a dime or the motor will spin over, but I have to press the gas pedal for it to crank. My truck doesn’t have a catalytic converter on it, but I also noticed one of the sensors wasn’t able to hook up I was told it was because that was supposed to go to the converter.

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Tuesday, December 21st, 2021 AT 6:27 PM

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Hi,

The idea that you have to depress the throttle at times for it to start leads me to think it may be getting flooded due to a fuel pressure issue or faulty injector. When you depress the throttle, it shuts the injectors off.

Three of the four codes are related to the oxygen sensors. If they aren't there, I'm not sure what to tell you on that. However, the P0339 is related to the crankshaft position sensor.

Do me a favor. Inspect the wiring at the sensor for damage. Also, disconnect it and see if there is corrosion or anything that can cause a voltage issue.

I attached a pic below showing the location.

Let me know what you find.

Joe

See pic below.

Image (Click to make bigger)