Rough start engine service light then fine
#1
Rough start engine service light then fine
This morning I started my Blazer it had a rough start sputtering and stalling and the engine service lightcame on right away. I kept tyring to get it going for awhile it kept stalling and sputtering and poping. The day before it was perfectly fine it's a 93 it's engine is a little over a year old. I thought maybe a fuel or spark problem it was really rough well it wouldnt stay on unless I was giving some gas so I shut it off popped the hood to take a look checked a couple of wires the fluids looked for anything burning or hanging off nothing....decided to see if it would run so I could take a look while it was on and lo and behold it was perfectly fine! I dont know what the problem was or is I'm yet to go start again maybe it will be acting up again but it got me to where I was going just fine. It was cold for the first time here in corpus but couldnt have just been a warm up no....something dirty or contaminated??? loose mayeb one of the wires I checked was loose and I didnt notice it.
#2
RE: Rough start engine service light then fine
My friend put his airflow sensor on backwards and had the same problem, however it didn't come and go, it was only fixed when he put it on the right way. Maybe its something with the airflow sensor.
#3
RE: Rough start engine service light then fine
hmmmm! dont know did again this morning...it's loud and odd enough to attract attention from nieghbors who come over and offer "maybe its" The odd thing is it just stops and is perfect afterwards. I did mess with wires and such again maybe tomorrow I'll mess with the wires before I try to start it maybe there is a bad or dirty connection...
#4
RE: Rough start engine service light then fine
I would suggest you get the codes scanned.
Typically when a problem like this occurs, the PCM will attempt to use sensor values up until it determines that these values are bogus. At that point, it will go to a predetermined 'map' that ignores the sensor(s) that it has determined to be faulty, illuminate the light on the dash to alert you that there is a malfunction, and go on. Now this 'map' is not optimum. So while you think the engine is running just fine, it actually isn't running as good as it would be running with all sensors operating normally.
*EDIT* - actually, now that I see it is a '93, you should be able to short one of the pins in the OBD connector and watch the check engine light blink to retrieve the codes. I'm not exactly sure on the procedure, but a quick search should turn something up. If not, I'm sure others will chime in.
Typically when a problem like this occurs, the PCM will attempt to use sensor values up until it determines that these values are bogus. At that point, it will go to a predetermined 'map' that ignores the sensor(s) that it has determined to be faulty, illuminate the light on the dash to alert you that there is a malfunction, and go on. Now this 'map' is not optimum. So while you think the engine is running just fine, it actually isn't running as good as it would be running with all sensors operating normally.
*EDIT* - actually, now that I see it is a '93, you should be able to short one of the pins in the OBD connector and watch the check engine light blink to retrieve the codes. I'm not exactly sure on the procedure, but a quick search should turn something up. If not, I'm sure others will chime in.
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