wolfgang wrote in
rec.crafts.metalworking on Thu, 31 Mar 2011 09:41:02 -0700 (PDT):

Me, I'm a firm believer in injector cleaners.

Last year my '93 RX-7 failed its emission test (180,000 Km) although
it runs like a top.:-)).

Scratching our heads (and other body parts) we concluded that the
secondary injectors were leaking. This from the fact that the engine
would idle a little rough after some "spirited" acceleration and
driving. Since the secondaries are only used during this spirited
phase of operation we concluded that these secondaries were leaking.

Ran the tank down and dumped in a bottle of Canadian Tire "finest"
magic fluid.

Passed the next test with flying colours! Had to explain at the test
station as to what we had done to cause the improvement! I don't
think they believed me.

Wolfgang

If you had let it go, you might have run into the problem with the old
1st gen RX-7s. When the injectors got leaky enough they would flood
the chambers from the rail pressure after running and you would lose
the seal, and get no compression for restart.
The hack was to wire a switch to the fuel pump relay and kill the
engine by cutting off the fuel pump. This left no pressure on the
fuel rail, so the injectors wouldn't leak into the chambers.
--

Dan H.
northshore MA.