Problems with my 94 Suburban TBI?

I rebuilt my 5.7 in January, I started off with 19mpg's when I did (bolt ons and high flow exhaust). Shortly after my mpg's dropped to 15.7, and sometimes worse but never better.

After the rebuild I noticed that I could here a "clicking" noise through the dash but the sound is coming from the TBI unit. The sound is from idle to about 2500 rpm's.

Now it is puffing smoking when I start it and driving up to 45mph, then it quits around 40-45mph I can smell strong gas fumes.

It is also pulling oil throught the air breather, and it is a considerable amount, I unhooked the one valve cover and it still is blowing out some oil, but apparently less.

No bad diagnostic codes and ignition does not seem to be an issue I am certain it is something to do with the TBI but what I am not certain. Could it be the regulator?

Check for an injector leaking out of the top or dribbling out of the bottom.

It could also be the fuel presure regulator leaking.

It is also pulling oil throught the air breather, and it is a considerable amount, I unhooked the one valve cover and it still is blowing out some oil, but apparently less.


Just a thought, did you remember to change the PCV valve? They're cheap and forgotten, if you haven't already you may want to try that first.