Tahoe not starting

[jjgorny]

1999 tahoe sport utility

Hey fellas, I need some more brain cells to put into this. My truck starts up and instantly stalls out. If I give it gas to keep the engine running, the engine picks up and revs, but it still instantly dies out when I let go.

I also have a misfire in cylinder 4 that was not there yesterday (when the truck was running.) the spark plug looks brand new, I just got this truck about 4 months ago. No issues other than a water pump and now this.

Other than inspecting the spark plug, I've also unplugged the MAF sensor and checked fuses, unplugging the sensor did nothing, and the fuses look to be also rather new.

Im not too mechanically inclined, so any ideas or suggestions would help. Thanks!

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please. If we can't see it, it does not exist.

Do you have, or have access to, a quality bi-directional scanner? It would be helpful to know what trouble codes are present, to start the troubleshooting process. Some local auto parts stores will hook up a scanner to your truck for free to obtain the trouble codes, but obviously, you can go anywhere in this condition.

Other members of this Forum much more knowledgeable than me in this area will chime in with troubleshooting tips that you can use at your location..

 

[jjgorny]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please. If we can't see it, it does not exist.

Do you have, or have access to, a quality bi-directional scanner? It would be helpful to know what trouble codes are present, to start the troubleshooting process. Some local auto parts stores will hook up a scanner to your truck for free to obtain the trouble codes, but obviously, you can go anywhere in this condition.

Other members of this Forum much more knowledgeable than me in this area will chime in with troubleshooting tips that you can use at your location..

Will send pictures after work. I have a friend bringing by a tester for gas pressure throughout the truck, I'll also ask if he has a bi directional scanner. P0304 is one code, and p0161 is the o2 sensor code, I've also been throwing off changing that one which I'll probably do today. Would the issue I'm having sound like a possible fuel pump/fuel injector issue?
I have a feeling it could be the fuel pump, but the code pointing to specifically the 4th cylinder as a misfire leads me to believe it could be an injector, but my mechanic friend says it's likely not the injector.
Another possibility could be that some mud got into the fuel filter? Only reason I say this is because I was doing some very slight offroading yesterday and the truck was running perfectly fine, up until I tried to start it this morning.

 

[Eman85]

Guessing will get you nowhere. Check fuel pressure first.
Of course we have no idea of the condition of this vehicle or how well maintained it is. Unplugging things will just set codes and break connectors.