1997 2.2 chevy cavalier p0300 random misfire fuel injector

I have a 1997 cavalier showing p0300 random misfire on cyl 1&4.
Changed plugs/wires/coil/ICM with no result. Swapped #3 injector for
#4 and miss followed injector. Swapped 1&2 and 3&4 and it followed the
injectors again. So now we are missing on 2 & 4.
I replaced the injectors indicated by the misfires. (2 & 4) Problem
came back
after a couple of days of driving, still missing on the same 2 brand
new injectors...(@2 & 4 cyl)

Anyone care to offer an opinion to this idea:
Is it possible that the 2 injectors that do not cause a misfire (now
at 1&3 cyl) are the wrong part and causing the problem? (I had
replaced all 4 injectors over the past couple of years one at a time
from whatever parts house was closest/cheapest when the old ones
started leaking)
Like if I put the 2 injectors I just pulled in 1&3 is there a
possibility that could
fix it? With the miss following injectors around it seems obvious its
not a wiring issue or a computer issue, right? Otherwise miss wouldnt
follow the injectors (unless I am thinking wrong somewhere) . And with
a brand new pair of injectors still misfiring (and the miss following
when I move them to different cylinders) it seems like that could be
the only possible answer. (Mind you, I spent $350 to have the dealer
replace a fuel regulator then say 'its possessed by a demon' and
scratch his head in the meantime here, or would just buy 2 more
injectors to make sure) I'm about ready to give up on the beast as
this problem is costing me about 10-15 MPG but would appreciate any
input from you all....

On Nov 25, 12:13 pm, "Steve W." wrote:
> wrote:
> > I have a1997cavaliershowing p0300 random misfire on cyl 1&4.
> > Changed plugs/wires/coil/ICM with no result. Swapped #3 injector for
> > #4 and miss followed injector. Swapped 1&2 and 3&4 and it followed the
> > injectors again. So now we are missing on 2 & 4.
> > I replaced the injectors indicated by the misfires. (2 & 4) Problem
> > came back
> > after a couple of days of driving, still missing on the same 2 brand
> > new injectors...(@2 & 4 cyl)
>
> > Anyone care to offer an opinion to this idea:
> > Is it possible that the 2 injectors that do not cause a misfire (now
> > at 1&3 cyl) are the wrong part and causing the problem? (I had
> > replaced all 4 injectors over the past couple of years one at a time
> > from whatever parts house was closest/cheapest when the old ones
> > started leaking)
> > Like if I put the 2 injectors I just pulled in 1&3 is there a
> > possibility that could
> > fix it? With the miss following injectors around it seems obvious its
> > not a wiring issue or a computer issue, right? Otherwise miss wouldnt
> > follow the injectors (unless I am thinking wrong somewhere) . And with
> > a brand new pair of injectors still misfiring (and the miss following
> > when I move them to different cylinders) it seems like that could be
> > the only possible answer. (Mind you, I spent $350 to have the dealer
> > replace a fuel regulator then say 'its possessed by a demon' and
> > scratch his head in the meantime here, or would just buy 2 more
> > injectors to make sure) I'm about ready to give up on the beast as
> > this problem is costing me about 10-15 MPG but would appreciate any
> > input from you all....
>
> Replace ALL 4 with a flow matched set. What you're probably seeing is
> that the used injectors are flowing more fuel than the new ones. The
> computer reads this as a misfire because the ones with more fuel
> generate more of a power pulse than the newer ones.
>
> If you replace all 4 with flow matched units it should take care of the
> problem by insuring that they are delivering the same amount of fuel.
> The problem with replacing them singly is that unless you're buying
> factory spec. NEW units they likely don't match in flow rate or pattern.
>
> --
> Steve W.
> Near Cooperstown, New York



So you're saying if I buy another pair of new (matching part#')
injectors from NAPA (where I bought the 2 new ones last week) I should
be good?
Thanks for your input!
Jason