Bought a 2002 Blazer S10 4.3L that has been sitting for 2 years. Got it running but it quits after a few minutes and will almost start but won't. I changed the fuel filter but same result. I disconnected the battery for half an hour and then it started. It gave me P0104 code. I started it today, it quit and gave a code P0300. Any suggestions as to where to start will be appreciated

 

I would start by checking your fuel pressure and spark.

 

theres lots of information about trouble codes on here in other locations. try using the search button.

 

Welcome from New York.

 

I missed an important symptom.....the security light is flashing which I didn't realize that "flashing" is abnormal.... but it does come on steady when the remote entry security is set.

I tried the 30 min re-learn procedure but no luck. I noticed the security light goes out 3 seconds after trying to start it.
I'm going to search through some other Passlock posts.

 

Are you sure that the code is P0104? I cannot find anything about that code in my references which are specific to your truck... Generically, it means MAF Circuit Intermittent, but it doesn't look like GM used that code for your year.

Erratic readings from the MAF sensor could definitely cause starting and other general performance problems. You should check to make sure that there are no vacuum leaks and no leaks in the duct work between the MAF sensor and the throttle body.

If you haven't tried cleaning the MAF, now would be a good time. Also, you can use one of the other MAF related OBD2 diagnostic links in the Tech Article (DIY) section to find the wiring diagram and test the wiring from the MAF sensor to the PCM.

 

Thanks for the Passlock re-learn as the security light has stopped flashing. It still won't start. You're probable right, I can't swear to the P0104 code as it has not repeated itself. The code P0101 is what is coming up now. I'll take your advice to clean the MAF sensor.
The duct where it fits onto the throttle body seems to be a little slack, would that be adding to the issue?

 

P0101 - Mass Air Flow System Performance
I would definitely suggest a MAF Sensor Cleaning and see how that impacts the problem. If it doesn't cure the issue, I would test the wiring from the MAF sensor to the PCM while moving the wiring around to make sure there are no internal breaks/shorts in the wiring.

 

thanks for your help. Checked the wiring with the trouble shooting procedure and ended up at "replace the MAF sensor". With the Ign on; Red wire has 12 V - yellow wire has 4.99V and Black is ground with the ign switch on and off. I'll see if I can get a MAF sensor tomorrow.