[T3] Mystery Miss

[Daniel Nohejl]

So over the last week, we’ve developed a miss under a variety of conditions. 

A little bit of background:

—Last summer, we’d get a miss after a few hours of driving on hot days. It’d happen a few times and then the car would die on the side of the road. 

—After changing a bunch of FI components, it went away. I’m still not 1000% sure which one fixed the issue but since the first week of September, the car hasn't died on the side of the road.

—In October, we were driving at about 50 up a slight hill and the car missed/bucked violently 4 times in a row. A minute or so later it happened again. After that, we were buck/miss free from October until Thursday of last week. 

—The only exception is that on cold and cool mornings, the car bucks like crazy at part throttle after start up. I can always accelerate through it though.

On Thursday of last week, we were cruising at 70 on a flat section of highway 2.5 hours into a 6 hour drive when out of nowhere there was a sudden miss/buck. It only happened once and not again until yesterday.

In the morning, I was accelerating up a hill in 3rd and when I got to b/w 45 and 50, the motor bucked/missed once. It didn’t happen again for the rest of the ride or at all on my trip home.

This morning, driving up the same hill as yesterday, I got to the same speed in the same gear and it missed 3 times. I was able to accelerate though it though. Then, about 30 seconds later, cruising on flat road in 4th at around 52, it missed a few more times and I was able to accelerate through it. For the rest of the trip, everything was fine until the last 200 yards or so. I was accelerating quickly through an intersection in 2nd gear and it gently missed/bucked 3 times. 

FWIW, yesterday was grey, cool, and humid and today it’s pouring out. 

I suspect I’m looking at an ignition system issue, but I also wanted to see if these symptoms rang any particular bells for anyone.