Hi there...I have a 2002 dodge ram van 1500 3.9L v6. I've blown 2 head gaskets in the past year and have had them fixed. Its running good now at idle and freeway speeds. I'm getting a low speed acceleration lag/bog down only between speeds of 5-50mph. There are no codes or check engine lights on. I've replaced the throttle position sensor, the plugs and wires were changed less than a year ago. Any idea why I'm getting a low speed acceleration hesitation?

 

Is 1st gear possibly blown, so that you're starting in 2nd? If you manually upshift you should be able to tell if each gear works.