Trying to solve a issue I am having. Truck runs good, smokes (black) underload. Boost levels correct fuel pressure correct according to scan tool. If I disconnect the MAP truck doesn’t smoke, Which I understand why. But what controls amount of fuel being delivered. I did try a used map, don’t know if it’s good.

 

The map is not just a map. There is a temp sensor built in as well.

It it is possible that the temp
sensor section of the sensor is bad and is leading the ecm to believe that you have low temp high density air entering the engine and over fueling as a result

There are a lot of competing interest governing the actual fuel delivery. One of them is a max amount of fuel that can be delivered vs air before you get soot creation. The ecm determines the amount of air by Measuring the pressure and temp and rpm and calculating the flow




Chay