2001 blazer 4wd Ls
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.
Plus, if the air leak is significant, the idle RPMs are going to increase or even surge on starting.
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; May 19, 2018 at 11:49 AM.
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



