Was the cap carboned up bad?

 

no, actually clean but had typical burns from the rotor.

 

Helping my Son troubleshoot his girlfriends Dads truck. Just getting started but engine intermittently stalls during idle in gear only. Engine is rough looking externally and idles rough. the ride is a 98 5.9 2WD.
What do you think your problem was ultimately?

 

Hey beech, any codes or check engine light?
How does air filter look?
Probably need to clean the throttle body.