Yeah, So i Recently purchased a 2003 blazer! It's in wonderful condition, Bought it for 200bux!! "previous owner was fed up with it"... so here's the problem, She turns over but only sometimes it'll start but it will stall, once i remove my foot from the peddle.. Thing's i've done so far.. 1, Checked fuel pressure, I GOT LOTS!, Replaced my fuel filter for something to do, 2, Cleaned Throttle body. 3, Replaced IAC Valve. 4, Checked all Vacuum Lines, 5 Checked all my grounds.6 Hit my head off the hood. 7 Replaced all spark plugs and cap and button and coil even tho i had spark to begin with. Anyway's i cant figure this out.. if someone has a soloution i'd bee Soo happy! Btw i ran my obd2 scanner on it and i picked up P0101 and P0449.. Still the problem seem's irrelevant to those dtcs.. OH! And when i try to start it, The REar window sometimes unlocks it self???

 

Hows the voltage on your battery and whats the air filter like and it when it runs dose it have power or dose it struggle to get up to highway speeds if it doses check your cats. My 03 blazer had the cats plugged and was running like crap removed them and it runs great if you can remove your cats and still have it legal you may want to do that although if you do it will probably run rich and give you a check engine light.

 

I would also clean the maf sensor and egr valve to see if it helps.

 

how did you check the pressure ? just wondering

 

well it has lots of power when it start's. i went out today and had it running for about a minute i had my foot on the floor, and it just shut off by it self after about a minute. i used a pressure gauge and seem to always be 60-58psi.. Flames, i just bought a brand new battery because one of the cells were low in my old battery. "refilled the cell's now the old battery works fine too".... ANyways, CATs? u talkin about my catalytic converter? One side of my Map sensor clip's are broken as of today. well atleast i noticed it today im gonna go change my map sensor in about an hour.

 

No, its the mass air flow sensor. If its dirty it will mess up the fuel to air ratio. I'm not sure if the 03 has an exhaust gas recirculation valve or not. The maf sensor will be inline on the air intake. Crc makes a maf sensor spray. Don't touch the wires when cleaning it! They are very delicate! Just spray them.

 

ya im talking about the catalytic converters on mine there were 2 on my 03 we cut open the first one and cleaned it out and welded it back up but it still had no power so we took it to a mechanic and the changed the mas sensor and it still had no power so they cut open the second one cleaned it out as it had managed to turn itself sideways and was not letting much exhaust out so they put the old mas sensor back in and it runs great now. How many kms are on it the timing chain might be streached so that when its resting it settles to the right spot but when its running it moves out of place just a suggestion.

P0449 is a code for the EVAP vent solenoid and valve located near the fuel tank.
I googled it.

 

I got it running today, CHanged the Map sensor and she fired right up! but hmm.. i got 3 more codes, i didnt write them down yet was just so happy she fired up. Anyways i drove it for an hour today. Previous owner didnt tell me the 4x4 didnt work!! i stuck it in 4x4 and it like jumps every 10 feet, and it sounds like it's grinding .. gonna take it apart tomorrow to see what i can doo. "this truck has sat for 2 years"... Local mechanic couldnt get it running.. . p0101 No longer exists.. i googled it last night and found that it could me related to the map sensor even tho it is for the MAF code.Also i remember this p0300! i just got that when i was done driving around for an hour.. Could that have anything to doo with me not changing the plug in cyl 1... I couldnt get my socket on that one spark plug. The steering column was in the way.. Figured i'd just ask my mechanic to change that one for me when i send it in for an inspection.

 

Also, i see smoke coming from Either Cyl 6 plug or Catalytic converter . it smell's like burning rubber? i originally thought it was oil cuz i just changed the oil on it when i got it runnin. but it's still smoking a bit their, My buddy think's it's my catalytic converter.. i think it's the cyl... my coolant looks dirty leading me to believe my head gasket is gonna go! Anyway to fix this before the headgasket goes?

 

P0300 is a random cylinder misfire code could be from the spark plug you couldnt change and/or the catalytic converters could also be causing it I suggest you get that spark plug changed soon and find out those other codes and glad to hear its running for you now

And if your head gasket goes you may have bigger problems with that like needing to change the coolent lines if oil has gotten into your coolent and I have no idea why a cylinder would have smoke that would smell like burning rubber so it could have something to do with something in the cylinder and the catalytic converter combined to create a burning rubber smell