FW: 5K hesitates, stumbles, pops, overboost?

[Livolsi, Stephane]

> My 1986 5KTQ 178K miles has developed the following over the last 2 weeks,
> getting worse every day:
>
> - under half throttle hesitates, then engine catches on a little bit,
> stumbles with more throttle
> - under full throttle hesitation gets worse, popping sound from underneath
> the hood, check engine light comes on briefly
> - pulled error code 2141 (knock sensor max, timing fully retarded)
> - in the early stages the hesitation occured only when cold but the car
> didn't pull that strong anymore during warm acceleration.
>
I had similar symptoms that I eventually traced to bad spark plug wires.  As
near as we could figure, the wires were arcing through the metal boot caps
and to the head.  Slid the metal caps further up the wire and problem was
resolved.

Easy and cheap diagnosis. Give it a try.

Stephane