I recently purchased a 99 Infiniti G20, and when I bought it, the
"service engine soon" light was on. I took it to AutoZone and had them
read the codes. The only code was Misfire on #1 cylinder. I changed
the plugs (put in NGK Platinum) and plug wires, but the code comes back
after every clear.

My gut instinct is to replace the #1 fuel injector.

Before I go after that repair, is there anything else I should be
thinking that could cause a misfire?

Thanks,

Steve

did you replace the distributor cap and rotor?

<steventhomas42 (AT) yahoo (DOT) com> wrote

Not yet. Would the failure of either one of those cause only #1 to
misfire?

its a good possibility, there could be a small crack or carbon trail in just
one spot, id replace the cap and rotor

<steventhomas42 (AT) yahoo (DOT) com> wrote

On Thu, 03 Mar 2005 23:05:23 GMT, "Shawn" <askmefirst (AT) mchsi (DOT) com> wrote:

Or even a bad plug wire or the wire touching the valve cover causing a high
impedance short. Does it idle smooth?

Just to give some closure on the issue... my mechanic friend found the
problem and fixed it. He explained it to me, and I'll attempt to
repeat it.

To help with emissions, some of the exhaust gases are re-routed back to
the cylinders. On my engine, the outlets to cylinders #2, 3 & 4 were
all clogged with carbon. That meant that all of the recirculated
exhaust gas was being directed straight into #1. That messed up the
air-to-gas mixture for number 1, thus causing the misfire.

In other words, it's a valuable lesson learned. There was nothing
mechanically wrong with #1, yet that's where the codes were pointing.

I don't regret changing the plugs and plug wires, as the motor calls
for Platinum and the mechanics recommend NGK, so I was just putting the
right plugs back in. The plug wires were the original ones, so it
doesn't hurt to have new ones.

The car runs like a top now.

Thanks for your help.