I have been having a really hard time trying to figure this Blazer out. First I was having issues with the idle being sporadic and trying to stall out while in gear. I have spent quite a bit of money on it. For it to still be having all these issues concerning air/ fuel. It was running fine before I changed plugs ,wires ,cap and rotor. I'll admit I caused an unneeded problem when I had to crawl on to the motor to reach the distributor. I accidentally broke the map sensor. I went to AutoZone and used there reader to get the codes. It said p0300 multiple misfries detected probable cause fuel pressure regulator. So I changed that ( after removing the intake I noticed the map sensor was broke. So after I get it all back together I fire it up and bam still p0300 code pops up so I check all the plugs , wires and cap and rotor . That's when I noticed I had swapped the 1 and 3 plug wires so I changed that back right.now I fire it up and no misfires but still have issue of fluctuating idle and attempted stalling scan the codes again and now I have tps code and aic valve code so I replaced both then it is still doing it and now the codes say ambient air intake sensor and mass airflow sensor voltage out of range so I replaced both of them and that brings me up to today. I am kind of at a loss here.its pretty much down to the ecm or possibly the assisted air fuel injector control module ( spider module) could some please give me a little of there knowledge and wisdom on this issue the idle is at 3000rpm

 

First some philosophy.

1. This rate of parts swapping can actually be causing more problems. You are probably replacing some good high quality OEM AC Delco electrical parts with inferior chineseum which can have a high failure rate. Your also dicturbing wiring harnesses, connectors, possibly causing voltage spikes, shorts, etc
2. When you get a sensor code that means that there is a problem in the circuit that involves the sensor, not necessarily the sensor itself. It may be a valid out of bounds sensor reading indicating another problem like a vacuum leak. It can also be voltages, grounds, wiring, fuses, etc
3. That many sensor codes points a more global problem like 5v/12v reference issues.
4. Yes the ECM can fail but it is very rare

I can help you here but your going to need scanner capability and a decent digital multimeter and we need to do some testing. If your up for that let me know and we will get you fixed up. Your first goal is to rule out a vacuum leak.

George

 

My concern with the ecm is that a diagnostic tool will not pull the vehicle info from the ecm. I purchased a elm327 Bluetooth obdii reader comparable with all obdii protocols and I can't get it to connect either.

 

But autozone was able to pull your codes? Read the original post in this thread:

https://blazerforum.com/forum/2nd-ge...lazers-103424/

George

 

is the IAC leaking?

Dumb question, but are the throttle plates closed on idle? Cruse control cable binding?

3K is a LOT of airflow, thats way more than idle air. There must be a throttle problem or air leak?