I have a 1990 chevy k1500 5.7 with 170,000 miles. Last year I rebuilt the engine and replaced all the sensors and switches under the hood. About a month ago, the fuel pump went out. I had it replaced. Since then I have replaced the ECM, coil, O2 sensor and the Ignition module with no success. I did notice that the throttle body is spraying way to much gas into the intake(even after I rebuilt the throttle body). I am getting no codes from the computer and no fuses are blown. Every mechanic I have talked to has no clue about what it could be. Any help would be appreciated!!

 

did u try changing computer

 

YES, It has been replaced

 

I had an '88 with the same problum years ago ----------- then it caught on fire in downtown Dallas, ended that problum! People love watching a truck burn.

 

I'd change the O2 sensor, could have a bad one.

 

CHECK FUEL PRESSURE I THINK ITS SAPOSE TO BE 25 TO 35 OF PRESS

 

what exactly are you having a complaint about? is it poor gas milage or poor performance ? i have an 89 and if you look into the throttle body as it idles it looks like a lot of fuel going thru. as mentioned , check the fuel pressure but on a tbi motor it is only 10-14 psi.

 

The truck will not stay running. it dies about 30sec after you first start it. it will not start back. If you push the pedal to the floor to "clear choke" it will hit and then stall back out..I have checked the fuel pressure and it is around 13-14 PSI

 

what i would do is have someone start the truck when cold and take the air cleaner off so you can watch the injectors and see what happens when it dies. then you will see if the engine dies while the fuel is spraying or if it quits running after the injectors quit spraying. i think then you might be able to narrow it down some.maybe it could be the ignition cutting out.

 

the jets keep spraying as it goes dead. I have a strong spark when it goes dead. I am going to find out if the guy at the autoparts store gave me the wrong computer