Map and maf sensor issues

[beardeddummy]

My maf and map are both reading weird and engine load reads at 18% at idle.

Maf reads 2.56g/s with the engine off and 8.0ish at idle

Map reads 10inhg at idle and 29.8 at wot accelerating.

My truck misses at idle only I'm stumped good on this. and about ready to say to hell with it and build a motor. problem is I don't have the money to build a motor or anything near a motor. compression check was done after I put heads on it and was good.

 

[Black_cirrus]

MAF should read 0 with the engine off, and warmed up at idle approx g/s is about the same as liter displacement. So 5.5-6.0 g/s, your maf reading is skewed, probably dirty or just a bad maf, your map sensor looks about right.

 

[beardeddummy]

MAF should read 0 with the engine off, and warmed up at idle approx g/s is about the same as liter displacement. So 5.5-6.0 g/s, your maf reading is skewed, probably dirty or just a bad maf, your map sensor looks about right.

Maf was replaced with close to same numbers and everything I have found tells me the map numbers should be opposite of what I'm getting

 

[Black_cirrus]

What does the maf read unplugged? And the map read engine off. If you've replaced the maf with no change time to check wiring for damage and dirty contacts.

 

[beardeddummy]

Engine off map reads 29.5 inhg maf reads 0 unplugged

 

[Christian Steffen]

It sounds like your MAP is reading correctly, considering it reads 29.5 with the engine off (atmospheric). I'm going to have to check what mine reads when the engine is off for each. There isn't a vacuum leak is there? If there was it would explain a the higher MAP reading at idle. What are your fuel trims doing?

 

[beardeddummy]

Map is low at idle only 10 and 29.8 at wot. bank 2 is off bad but not sure why chasing that lead me to this actually. bank misses mainly just #2

 

[Christian Steffen]

You're saying it should read more the 10 inHg(really should have this in psi or kPa) at idle? MAP sensor reads inverse to vacuum, so low at idle due to high vacuum and high at WOT due to low vacuum (essentially reading atmospheric pressure at WOT).

In a recent data log that I have I saw anywhere from 3.48 psi (7 inHg) at low rpm low load to 13.3 psi (27.1 inHg) at higher rpm and load.

If your fuel trims are messed up that could point to a vacuum leak, as that would be air leaning out the mixture causing the computer to add fuel. Only one bank being off doesn't really point to that though.

 

[beardeddummy]

Mixture is rich on bank 2. thinking i may not have the rocker arms adjusted right may be just a hair tight on that side

 

[beardeddummy]

You're saying it should read more the 10 inHg(really should have this in psi or kPa) at idle? MAP sensor reads inverse to vacuum, so low at idle due to high.

And that is where I got lost