solution to SR20 cold hesitation at 1600 rpm.

[Ben McGee]

G'day from Ben in Australia.

I've been trying to fix a hesitation, when the engine is cold, (cold in
Sydney is 0 - 8 degrees Centigrade) in my wife's '92 Pulsar 5 door hatch
(SR20 engine) for some time now.  I've read all the "fixes" I could find on
your pages and others, but none of them were causing my problems.
I never dreamed of checking the Oxygen sensor in the exhaust because I'm
such a genius, knowing that it only works in the "closed loop" cycle when
the engine is hot.
Anyway, you guessed it, the Oxygen sensor was stuffed!  They cost A$268
here!  You guys have it good for well priced spare parts.

Maybe you'd like to add this suggested cure for an engine that hesitates at
about 1600rpm when the throttle is transitioning from leading to lagging and
back again and the engine is cold.    Check the oxygen sensor.  Three wires
connect to it.  One is +12v ignition to heat it up, one is earth, and the
third one is the output which should toggle between approx. 1 volt and no
volts several times per second when the engine is warmed up thoroughly and
revving at about 2000rpm.

The SR20 engine is a ripper!  It pulls strongly all the way up to 7500rpm
(over 100 KPH in second, don't tell the wife!), it pulls away smoothly in
4th gear from about 30KPH and God knows what it would do flat out in 5th!
We have been getting 43 MPG (English gallons are 25% bigger than American
gallons) from new, and it's 10 years old now!

Rgds, Ben McGee
Tier II Transmission Support
Optus, Rosebery
02 9342 0029
0412 020 545