Miss/stumble

[73john]

The truck has a miss/stumble at low RPMs. Otherwise the truck runs great. The miss stumble is not consistent, might run well for a while and then stumble for 2-4 seconds. There are no codes present. Where is the best place to start and easiest ways to test. What would be the most common problem? I would think plug wires/coil. Thanks for the advice in advance.

 

[73john]

Since the truck had an earlier code of low fuel pressure, I replaced the filter. Truck stumbles when you pull hard from a low RPMs and runs great down the highway. I decided to pull the fuel pressure regulator vacuum hose leaving it open to the air and the truck ran exactly the same with the stumble. Does this indicate a weak/bad regulator? Is a stumble/ hesitation caused by weak wires/coil more prevelant at low RPMs or should I also get a stumble at highway speeds also?