LT1 stalling, MAF readings and bypass valve.
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Teching In
Joined: Mar 2009
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From: Butler, PA
LT1 stalling, MAF readings and bypass valve. The car is a 94 TA LT1 with a P600 Procharger on it.
My car was stalling every 30-45 seconds when idling after its warmed up and throttle response was real jerky when getting on or off the gas going down the road. I replaced my IAC and my left O2 sensor that was being goofy. My MAF readings were between 11-14 gps at idle. I replaced the MAF sensor today and now my readings are 7.5-10.5 gps. It still has a slight stalling issue, not nearly as bad, and throttle response driving down the road seems normal.
I have checked for vacuum leaks, loose grounds, etc. The only thing I can think of that I did to it over the winter that would have any effect on idling whatsoever is that I eliminated the PCV system. It was a 2 hose system with an elbow coming from a valve cover and the PCV valve in the IM and both hoses running into the intake elbow in front of the blower but behind the MAF. I then put an "abbreviated" PCV system back on it. I ran a hose going from the PCV valve to a vacuum nipple on the TB and it made no difference.
When I remove the vacuum line for my bypass/blow off valve and cap the nipple, my MAF readings are a steady 5.6-5.8 gps and it idles perfectly.
What gives?? What should my MAF sensor readings should be being that its Procharged? Could my bypass valve be messed up? And why is disconnecting the bypass valve correcting my idle and changing the readings whenever it recirculates behind the MAF?
I would greatly appreciate any advice.
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My car was stalling every 30-45 seconds when idling after its warmed up and throttle response was real jerky when getting on or off the gas going down the road. I replaced my IAC and my left O2 sensor that was being goofy. My MAF readings were between 11-14 gps at idle. I replaced the MAF sensor today and now my readings are 7.5-10.5 gps. It still has a slight stalling issue, not nearly as bad, and throttle response driving down the road seems normal.
I have checked for vacuum leaks, loose grounds, etc. The only thing I can think of that I did to it over the winter that would have any effect on idling whatsoever is that I eliminated the PCV system. It was a 2 hose system with an elbow coming from a valve cover and the PCV valve in the IM and both hoses running into the intake elbow in front of the blower but behind the MAF. I then put an "abbreviated" PCV system back on it. I ran a hose going from the PCV valve to a vacuum nipple on the TB and it made no difference.
When I remove the vacuum line for my bypass/blow off valve and cap the nipple, my MAF readings are a steady 5.6-5.8 gps and it idles perfectly.
What gives?? What should my MAF sensor readings should be being that its Procharged? Could my bypass valve be messed up? And why is disconnecting the bypass valve correcting my idle and changing the readings whenever it recirculates behind the MAF?
I would greatly appreciate any advice.
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