Anybody care to comment on this data log? Just trying to figure out poor running and idling '97 420a. N/A.

TPS 12.9
RPM 850-900
LOAD 9.0
MAP 18.6-19.2
COOLANT 178
IAT 41
IGN ADV 4.0
ST FTRM 0- -1.6
LT FTRM -18 - -19.5
FUEL SYSTEM1 closed
O2S1 .470 - .510
O2S12 .47

This is at idle, I will add a cruising data log later on today.
I am new to reading data, but I thought the fuel trim and the map sensor reading looked odd. Also this is after a new cam sensor.

Any help or thoughts on this would be greatly appreciated.
Almost forgot, no cat.

A 55 MPH run showed the fuel trims being
ST= -5
LT= -20

long term is never higher than -15

Would this be a rich condition? Front O2 seems to be operating properly and it is relatively new.

What are your compression numbers?

Have you examined your timing?

How old are your fuel system and ignition components?

Given the age of our cars, in my opinion, I would start by ruling out any abnormalities in the physical parts of the car first. When you know they are all up-to-date and functional, then I would proceed to other electronic methods of testing.

Your scanner may not be able to help you find popular items that cause your condition such as:

- Failing Crankshaft Position Sensor
- cracked ground at the coolant temperature switch
- Cracks in the ignition coil
- Worn out "O" ring in some fuel pump assemblies
- Clogged fuel filter
- Low compression

and a host of other things.

Sorry I guess that wasn't enough info. The motor has a fresh rebuild (this year in July. Good fuel pressure, Walbro fuel pump, new filter, new OEM coil (after trouble with the MSD coil I previously had on it), new wires.

I am fairly certain this is not an ignition, spark, or timing problem. Most sensors on the car are also new. Cam sensor this week, IAC, EGR valve and solenoid, Front O2...about the only thing that hasn't been changed is Crank sensor, TPS, upper temp sensor, yes I am aware that it plays into the fuel trim, and the MAP sensor. However, the map sensor is only two years old. Also wouldn't I get a code for any of those if they where bad?

So back to my original question. Do these readings look normal, and if not how out of whak are they? If they are abnormal, does anybody have an idea as to why?

I have done my research. I have looked at other peoples posts of their logs. The problem is most everyone that posts that kind of stuff is also having problems. I have not seen a data log that is from a well running car.

Before you ask if I have any vacuum leaks, the answer is no. I have hunted all over the engine bay to the fuel tank and cant find any.