My GMC 1500 4x4 with a 5.0 has a pulsing problem between 40 and 55 it seems like a fuel problem - but there is no code light on -- I need help - I love my truck - but nobody seems to know or have an idea of what it is !!! HELP !
I would check the fuel pressure, and I would also check all
the running parameters. Pay close attention to the fuel and ignition parameters.
You may have a sensor failing but it is still within the set parameters of the
PCM. Knowledge and a quality scan tool may help.
Did you upgrade the suspension or tires? Sometimes if this
work is not done correctly it can cause problems.
What year is your truck?