Running WAAAYYYYYY Rich. Where do I start?
 

Well at the ole' 951 at the CA Smog station and as I expected, it didn't pass. I figured such as my fuel mileage has been steadily decreasing I have assumed it was running rich. Well I was spot on with that assumption. In fact it's running so rich the car is WAAAYYYY in excess of even the CA "Gross Polluter" standard. Specifically, the CA state max for HC (in PPM) @ 15 mph is 115, the GP is 308 and my car measured 402! At 25 mph (in the same order) 75, 258 and 247.

Obviously there is something wrong here. I have replaced the plugs, the cat and the O2 sensor as well has just changed the oil. I have a new rotor and cap but haven't installed yet.

So the question is, where do I start to look/replace parts in trying to remedy this situation? FWIW, the ecu is stock and came from Rogue Ant last year.

Any and all suggestions are welcomed and appreciated.

Michael

Check Fuel Regulator & Dampner
 

Boostbuggy;

I would check them both with and without vacuume. The oem should be at ~36psi or 2.5bar at idle 840rpm. They have a tendency to get stuck.

I would upgrade to an adjustable FPR form Lindsey Racing <Dave>.

Later...

And how does one do that? i.e. chk the FPR and the Damper? And where are those two parts? Sorry, this is new area for me and I'm really not familiar with what the parts are and/ore where they're located/look like.

Thx

Check your fuel pressure at the rail. This will determine if the fuel pressure regulator is bad or not. Check condition of the vacuum line for the regulator also.

Replace the DME temp sender, it is inexpensive and easy to replace (i wouldnt waste the time to test it) and will cause rich running conditions.

Another possibility is the AFM is out of adjustment, check the above two first as they are the most likely.

How do you chk the FPR? As the car has 227k on it I don't mind just replacing easy inexpensive parts like the DME Temp Sensor but with the FPR being more like $100+ I'd rather check it before replacing.

You have to check fuel pressure at the rail, this will tell you if the regulator is bad or not.

fuel pressure according to clarks-grage is supposed to be 29 psi at idle. 36 psi is when jumpered.