engine choking up on acceleration (long)

[Joy Cordell]

Hi--

When I got my '98 200SX SE-R it hadn't been driven much for 2-3 months and
only had about 3/8 tank of gas. When I got under 1/4 it started choking and
lurching episodically on acceleration and I figured the gas was old and
filled the tank. (Right about this time the Service Engine light came on and
the mechanic who checked out the car told me the code was for the knock
sensor.)

I filled it with gas a couple of times but the problem persisted when the
gas was low. I bought HEET, filled the tank, ran it down, same problem. Then
I put in fuel injector cleaner (now I just read that I shouldn't do that in
this engine, darn) took the car on a nice freeway drive down to Portland,
and when in Portland and shifting up and down, it started doing the same
thing at a half tank. I was pushing the rpms a bit hard to see if I could
burn some carbon out or something. Didn't like that.

If I drive the car very gently, the problem won't show up until I'm under a
1/4 tank. If I accelerate hard in lower gears and "push" it, it shows up
earlier.

Fuel injectors need blowing out? Wouldn't that be an issue no matter how
much gas I have in it?

Fuel pump need replacing?

The BPT tube needs cleaning out?

Am I also guessing right that this problem probably blew the knock sensor
and I should deal with it before getting that spendy thing replaced?

BTW, when the mechanic checked over the car, he said engine compression was
fine on all counts (180s to 185s).

Greatly appreciate all insights.

Joy

__________________________

'93 charcoal SE-R, stolen and still missing in Seattle (314 GXL)
'98 timber frost 200SX SE-R with the back end of an SE welded on and I'm
going after that dealer for fraud