4.3L vortec help PLZ!!!!
#13
yes - again - crank sensor relearn. But it has to run first! Why can't you believe me? I've said it several times now and I'm getting tired of repeating myself.
Last edited by LesMyer; 07-18-2017 at 11:06 AM.
#16
I just created an account to get into this forum, I'm not certain if I'm posting this in the right place or not.
I have, both a comment on the above, as well as some questions that are driving me crazy at the moment!
First, I have a 1997 Blazer 4x4 with a 4.3 V6, and a few days ago I was certain that this engine had jumped time, because I have spark at the plugs, even poured a cup of gas into the throttle body, and it wouldn't fire at all!
So I was in process of ordering a timing chain / gear set, and doing research I discovered that unlike, back in the day where you bring #1 up to TDC and drop in the distributor to approximate electrical timing then finish up with a timing light, that this particular engine is very specific as to the distributor position as it only drops into an exact position and everything from there is computer controlled!
So before tearing my engine apart, I brought the timing mark up to TDC, and found that the distributor was in the exact position it is supposed to be, indicating that my engine had not jumped time!
Here is a diagram that shows the positioning of the rotor:
This image shows the rotor pointing to the 8 stamped into the edge of the distributor, which is for V8 engines, and it's a 6 for V6 engines. When the distributor is set completely flush (bottomed out), this is the correct and exact location it needs to be in - period!
I hope this helps and puts light onto the inquiries above.
As for my issue, once I discovered my engine was perfectly in time, I was confused and stumped as to why it wouldn't start. I rented a scan tool from Autozone, and the computer had a few codes stored:
P0300 Engine Misfire Detected
P0101 Mass Airflow Sensor Performance
P1153 HO2S Insufficient Switching Bank 2 Sens 1
I cleared the codes, and removed and cleaned the Mass Airflow Sensor, and still no change, it would crank all day but not even fire, even if I dumped gas into the engine!
Finally, I spoke with a friend who suggested unplugging the MAF Sensor, and after clearing the codes cranked it over. I told him that was CRAZY, but tried it anyway and low and behold it started!
At this point I plugged the MAF sensor back in, and it kept running, so I shut it off and started it again, no problems!
So I finally was able to drive to work, after missing 2 days of a new job... I drove to work 3 days, and it ran really rough, I figured I would need to replace the MAF soon.
Then Sat morning, I got up and tried starting it, and now it fires as soon as I turn the key, but it won't start. I tried unplugging the MAF sensor, but no change. I don't have the scan tool now, so I even left the battery disconnected and shorted the cables together to ensure it drained and reset the computer, but even after that there is no change. It cranks, starts to fire at first, but won't start!
My friend thinks I have a bad MAF Sensor that fried the computer. At this point now I am looking at renting a car for a month so I don't loose this new job, but I'm totally confused about this Blazer...
My questions are:
1. Is the computer plug & play, or does this FLASH process have to be done for it to run?
2. What is this FLASH process, and how do I get it done without paying a dealership $$$?
3. Can the MAF Sensor fry the computer?
Any help on this matter would be greatly appreciated, I'm struggling to keep above water and can't afford to loose this new job!
I have, both a comment on the above, as well as some questions that are driving me crazy at the moment!
First, I have a 1997 Blazer 4x4 with a 4.3 V6, and a few days ago I was certain that this engine had jumped time, because I have spark at the plugs, even poured a cup of gas into the throttle body, and it wouldn't fire at all!
So I was in process of ordering a timing chain / gear set, and doing research I discovered that unlike, back in the day where you bring #1 up to TDC and drop in the distributor to approximate electrical timing then finish up with a timing light, that this particular engine is very specific as to the distributor position as it only drops into an exact position and everything from there is computer controlled!
So before tearing my engine apart, I brought the timing mark up to TDC, and found that the distributor was in the exact position it is supposed to be, indicating that my engine had not jumped time!
Here is a diagram that shows the positioning of the rotor:
This image shows the rotor pointing to the 8 stamped into the edge of the distributor, which is for V8 engines, and it's a 6 for V6 engines. When the distributor is set completely flush (bottomed out), this is the correct and exact location it needs to be in - period!
I hope this helps and puts light onto the inquiries above.
As for my issue, once I discovered my engine was perfectly in time, I was confused and stumped as to why it wouldn't start. I rented a scan tool from Autozone, and the computer had a few codes stored:
P0300 Engine Misfire Detected
P0101 Mass Airflow Sensor Performance
P1153 HO2S Insufficient Switching Bank 2 Sens 1
I cleared the codes, and removed and cleaned the Mass Airflow Sensor, and still no change, it would crank all day but not even fire, even if I dumped gas into the engine!
Finally, I spoke with a friend who suggested unplugging the MAF Sensor, and after clearing the codes cranked it over. I told him that was CRAZY, but tried it anyway and low and behold it started!
At this point I plugged the MAF sensor back in, and it kept running, so I shut it off and started it again, no problems!
So I finally was able to drive to work, after missing 2 days of a new job... I drove to work 3 days, and it ran really rough, I figured I would need to replace the MAF soon.
Then Sat morning, I got up and tried starting it, and now it fires as soon as I turn the key, but it won't start. I tried unplugging the MAF sensor, but no change. I don't have the scan tool now, so I even left the battery disconnected and shorted the cables together to ensure it drained and reset the computer, but even after that there is no change. It cranks, starts to fire at first, but won't start!
My friend thinks I have a bad MAF Sensor that fried the computer. At this point now I am looking at renting a car for a month so I don't loose this new job, but I'm totally confused about this Blazer...
My questions are:
1. Is the computer plug & play, or does this FLASH process have to be done for it to run?
2. What is this FLASH process, and how do I get it done without paying a dealership $$$?
3. Can the MAF Sensor fry the computer?
Any help on this matter would be greatly appreciated, I'm struggling to keep above water and can't afford to loose this new job!
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