Can a defective or inaccurate map sensor cause hp loss?
05-19-2003, 10:17 PM
#1
Just curious if it can happen where map sensor sends not so accurate readings to the ECU and leans out A/F ratio too much that peak hp suffers. My car dyno'd stock at 197 peak hp, but with AEM it dyno'd 193-195. AEM did increase lowend and midend punch(+20hp and 10 lbs/tq at 5800-6000 rpm) but curious why my peak hp didn't increase? I've heard people having problems with map sensor where it makes their car bog and hesitate but can it also have an affect on peak hp? Anyone change to a new map sensor which in turn made their car run better?
05-20-2003, 06:30 PM
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Your best bet (since you have a variety of variables here.. did I just say that?) is to strap it down to a dyno and tune it by the A/F on a wideband O2 sensor. I doubt it is your stock map sensor, however, if that's bad or leaking, you'll notice very quickly: bucking car, car won't idle or possibly even start, LARGE loss in horsepower (like 50-75%, not 1-2%), etc.
Go check on a dyno, make sure your A/F is not to rich, then start looking for problems.
Go check on a dyno, make sure your A/F is not to rich, then start looking for problems.
05-20-2003, 07:50 PM
#5
Make sure you reset the ECU after installing the new MAP sensor. The ECU will learn to compensate for slight variations in the signal, so a different MAP could change your Air / Fuel ratios a bit one way or the other for a short time.
05-20-2003, 08:13 PM
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Originally posted by hyperpm
Just curious if it can happen where map sensor sends not so accurate readings to the ECU and leans out A/F ratio too much that peak hp suffers. My car dyno'd stock at 197 peak hp, but with AEM it dyno'd 193-195. AEM did increase lowend and midend punch(+20hp and 10 lbs/tq at 5800-6000 rpm) but curious why my peak hp didn't increase? I've heard people having problems with map sensor where it makes their car bog and hesitate but can it also have an affect on peak hp? Anyone change to a new map sensor which in turn made their car run better?
Just curious if it can happen where map sensor sends not so accurate readings to the ECU and leans out A/F ratio too much that peak hp suffers. My car dyno'd stock at 197 peak hp, but with AEM it dyno'd 193-195. AEM did increase lowend and midend punch(+20hp and 10 lbs/tq at 5800-6000 rpm) but curious why my peak hp didn't increase? I've heard people having problems with map sensor where it makes their car bog and hesitate but can it also have an affect on peak hp? Anyone change to a new map sensor which in turn made their car run better?
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05-20-2003, 09:18 PM
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Originally posted by hyperpm
So after every mod (ie: intake and/or exhaust), good idea to reset ECU? Does it really relearn the air/fuel curve? Or does it do it temporarily then goes back to stock air/fuel curve?
So after every mod (ie: intake and/or exhaust), good idea to reset ECU? Does it really relearn the air/fuel curve? Or does it do it temporarily then goes back to stock air/fuel curve?
if you want immediate results, reset the ECU ASAP. but if you let it be, it will automatically relearn the new properties on its own, but it will take a while.
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