Expert: Van - 2/2/2006

Question
 Van,
 I have a no start problem,it's an87'gmc 454w/tbi
  It looks to me as if it's pumping too much fuel. It does not even try to hit. Ihave fire to the plugs. Got any ideas?
                          Craig Drake  

Answer
Hi Craig,
The early model TBI like that should have 13 PSI of fuel pressure while running. About 15 is all the pump will put out, even if you clamp off the return line, so a pressure regulator shouldn't cause a bunch of fuel to pour into the throttle bores.
The injectors have an O ring under them that could leak and dump fuel.
They are easy to remove, and the throttle body itself is easier to repair than a carb. But there is pressurized fuel inside it when the pump is running, so a leaking gasket would allow fuel to pour in the throats also.
The pressure regulator has a diaphragm, and could also leak.

If it is pumping water, due to a bad tank of fuel, it also will not hit. Have you pulled a plug or two to see if they are wet, and with what?

I would expect to see a nice cone of fuel under each injector.

Van