'93 SC2 - high HCs >:(

Well, it just about passed the test this year, the HC's were high - .66
Vs the .80 limit. The NOx and Co were low, less than 30% of the limit.

It's got a recent cat, new injectors, and the motor was reringed a few
months ago.

Mileage is generally horrid on the thing - low 20's in town, mid 30's on
the highway.

No trouble codes, naturally...

I'm stuck here, guys. My only two guesses are the ever popular O2
sensor, or the fuel pressure regulator on the rail. The mechanic claims
the EGR valve might be messed up, but I thought that was an NOx thing,.

So, am I at least somewhere on the right track fingering the EFI, or am
I totally lost here?

Oh yeah, the plugs are a bit old - time for new ones?

Re-ringed is good. I assume that you also had the cylinder bores honed and
the valve stem seals replaced. both will cause higher HC from oil burning if
not done.
Look also at these:
PCV valve ?
EGR flowing too much
O2 sensor
fuel pressure
ignition timing
MAP sensor
Throttle sensor

Otherwise I haven't a clue
Oppie

"Philip Nasadowski" > wrote in message
...
> Well, it just about passed the test this year, the HC's were high - .66
> Vs the .80 limit. The NOx and Co were low, less than 30% of the limit.
>
> It's got a recent cat, new injectors, and the motor was reringed a few
> months ago.
>
> Mileage is generally horrid on the thing - low 20's in town, mid 30's on
> the highway.
>
> No trouble codes, naturally...
>
> I'm stuck here, guys. My only two guesses are the ever popular O2
> sensor, or the fuel pressure regulator on the rail. The mechanic claims
> the EGR valve might be messed up, but I thought that was an NOx thing,.
>
> So, am I at least somewhere on the right track fingering the EFI, or am
> I totally lost here?
>
> Oh yeah, the plugs are a bit old - time for new ones?
>