1997 Buick Park Avenue Ultra 3.8L SC with code p0171

Question

Hi Reynaldo,

I clear code 'p0171', then I disconnect MAP sensor and got code 'p0107' start the engine and got this readings

MAF 4.57
MAP 8
IAT 78
IGN ADV DEG -21.6
ST FT 1% 20.3
LT FT 1% 16.4

ST FT 11% 20.3

Then when engine was idle I connect MAP sensor and MAP reading change to 35. Rest everything was same.

Thanks in advance

Answer 1

The test you went through just points to one symptom and thats the fuel delivery, I read where you disconnected the 02 sensor, and cleared the code> Fuel trim is votile that means when you turn off the engine it resets itself at long trim at 16 and short goes to 0. The data is still too you,I am sticking with the fuel as being the culprit, Pressure is good but volume is questionable, Fuel pressure is created in the fuel lines, by the fuel pump compressing the fuel, even if the fuel pressure is good the volume can be low,There can be a fuel leak at the fuel pump feed line, the pressure will be good but the volume will be low,I sticking with the fuel pump as the problem.