1990 GMC Sierra*****5.7 TBI
Runs great for until warmed up...10 or 15 minutes. Then it will stall/bog down...have to feather the throttle to keep it going and even then 30 or 35 is tops.
It will still idle fine at that point...it also starts up easily when it is warmed up.
My fuel pump shows 13 psi...backpressure is about a pound or pound and a half.
vacuum is 17 or so...
have changed coil, plugs, temp sensor. The rotor and cap look new. I have put some seafoam and chemtool in it.
it was throwing EGR code but the hook up was all goofy...fixed that and the code went away.
other code is MAP sensor.... but the service engine
light is not on, no service lights are on.
i am not a mechanic, but have worked on/at cars since my first one in '75.