wvsilveraldo

My wifes uncle has a 1999 crew cab with a 454 in it. His check engine light is on and it stalls out after start up but starts right back up. It also has stalled at times at idol. It gives a code for mass air flow and he has changed it twice the second time with a "better one" from advanced.He was told it could be the cam senser and has changed it also. We dont know what to do from here. The codes were cleared every time with the scanner. Any advice would be appreciated.

wvsilveraldo

No replies.... Why?

shamrock246

did you check the voltage going to the sensor?is there a signal voltage going back to the ECU?

Sean

97 4x4 burb

wvsilveraldo

No.The voltage to the sensor was not checked nor was the voltage to the ECU. So your saying thats a good place to start? What should the voltage be?

shamrock246

pull the connector off and measure between the pink and black/white wire with the ignition on(engine not running) you should get 12volts if not check ENG-1 fuse,the yellow wire is the signal wire goingback to the ECU you could check from the connector to the ECU for contnuity and the connector to ground to make sure there isn't a short to ground, the signal going back to the ECU would be a voltage less than 12v,what was the number of the fault code you were getting?check the condition of your grounds on the 5.7 theres one by the t-stat housing and one down near where the old mechanical fuel pump used to be mounted make sure there clean and tight



Sean

97 4x4 burb

wvsilveraldo

Yes sir Sean, we checked the fuse and of all things it was gone. He just bought the truck and we cant understand why it didnt set the light off sooner, but it is beside the spare fuse and we think it was taken by accident. Thanks for the advice it was truly appeciated.

shamrock246

cool sounds like you got it both my chevy and my toyota will start and run without a problem with the mass airflow sensor disconnected, that eng-1 fuse sends power to other stuff on the engine, O2's,EGR valve etc.


Sean

97 4x4 burb