3406B low power

[clinton_00]

i have a 1993 peterbuilt with a 3406 b model engine. it came from california. i was wondering if there is a valve that limits fuel until so much boost. the truck is unstoppable once it reaches higher boost levels. it hardly smokes at all more like a E model.

[nevrenufhp]

Yep, there's a diaphram that will limit fuel until boost hits. It's replaceable, as are most of the parts inside the pump. You can take off the supply line and test it with a few pounds of air and see if it holds it.