So, I just picked up my Disco last week, and have been driving her around this weekend to shake things loose and see what needs to get fixed.

While driving (took it on a 400-mile round trip) on the return leg it started to stutter at around 60MPH and hesitate. At first, the ultragauge speedo started to spazz out - threw speed alarms saying I was going over 90MPH! No codes. Spontaneous resolution.

The second time it started to spazz the same, but was able to get to the ultragauge in time to see two pending codes: P0300 and P1316. Both cylinder misfire.

It never popped up as a true engine trouble code, and the pending codes cleared themselves. Idles fine, and no other significant changes noticed.

I'm thinking it's plugs/wires based on codes alone. With the spontaneous clearing of the hesitation and trouble codes, should I be thinking about other causes (vacuum?)?

Thanks in advance.

 

VSS (vehicle speed sensor) is going south.
Do the tune up and see if it happens again.
But the speedo going over 90mph on the U-G is a sure tell sign of the VSS throwing a false signal and setting off the speed limiter.
The speed limiter cuts spark to slow you down thus the mis fire codes.

 

Excellent, thanks! Makes total sense...U-G speedo reading would freak out, then the hesitation and cut-out. The actual vehicle speedo showed "true" speed (didn't show 90's...showed whatever I was going).

I'll mention it to the LR tech - haven't met him yet, feel like I should bring cookies or donuts or something.