2001 blazer 4wd Ls
#21
Once again Block the flow in a vacuum hose that goes to a manifold, not pull off. If you block it then You surely have no leaks through a vacuum hoses, right? If that helps it means You had a leak into the hoses, if it does not - it means vacuum lines are ok.
#22
Plus, if the air leak is significant, the idle RPMs are going to increase or even surge on starting.
#28
MAF readings are usually stated in grams per second. At idle, that number should be around the displacement of the engine or 4.6 g/s ish. The stated amount in pounds per second is too coarse for a useable conversion. This is only a general rule of thumb and more diagnosis is required to properly assess the MAF sensor function.
Your fuel trims (LTFT+STFT on a given bank) have changed dramatically. Have you changed anything on the truck to account for this? Also please restate all 4 fuel trims from both measurements with plus and minus signs on every number. I cant tell if the "-" marks are punctuation or negative numbers and if the lack of a sign means positive numbers.
George
Your fuel trims (LTFT+STFT on a given bank) have changed dramatically. Have you changed anything on the truck to account for this? Also please restate all 4 fuel trims from both measurements with plus and minus signs on every number. I cant tell if the "-" marks are punctuation or negative numbers and if the lack of a sign means positive numbers.
George
Last edited by GeorgeLG; 05-19-2018 at 11:49 AM.
#29
As far as drastic change in the fuel trim numbers I cleaned TB changed all vacuum lines as far as new # shrtft1 -0.8 LONGFT1 +11.7. shrtft1 +1.6. LONGFT2. +13.2 I changed to metric on scanner and got MAF 8.6 g/s rite at 890rpm