[Quinlan]

Hi all
I am at my wit's end with this.
I have a 1985 3.2 Carrera engine transplanted into a 1979 body.
During the transplant process I tried to proactively deal with any maintenance issues by replacing the following:
1. Idle control valve
2. Speed sensor
3. Reference sensor
4. Cylinder head temp sensor
5. Spark plugs
6. Fuel pump
7. Fuel filter
8. Fuel tank
9. Fuel lines to and from the engine, including the lines on the engine
10. Ignition rotor
11. all vacuum hoses
12. DME relay
13. DME was checked and re-soldered by Ingo Schmidt
14. New headers and exhaust from RarlyL8

There are probably other things as well.

Other than the headers the engine is completely stock.

I've never had the engine running (properly) - I bought it used.

The engine fires up immediately, but idle starts hunting immediately. According to my Innovate LM-1 wide band sensor, air/fuel ratio is very lean - 18 or 19.

After about 2 minutes idle settles down, and air/fuel goes to normal - 14.2 or so.

After another 3-4 minutes the mixture leans out again to 18 or 19.

If I rev the engine to 2,000 or so, mixture returns to 14 or so.

I've done a fuel pressure check and according to my gauge both the system pressure and running pressure are about 10% high - I would have thought this would cause it to run rich if anything?.

I've checked all the sensors with a multi-meter and all are within spec, including the speed and reference sensors, the idle control valve and the cylinder head temperature sensor both cold and warm.

I opened up the AFM and tried adjusting the sensor tracks - no change. I tried adjusting the clock spring and although this helped the idle mixture, it made the mixture too rich at higher rpms.

I've run it with the O2 sensor connected and disconnected - no change.

I've done a smoke test and there are no leaks.

I re-torqued the intake manifold bolts.

I'm trying to understand what input would cause the lean idle mixture? I'm embarrassed to drive the car the way it is running now, not to mention that I can't see that is would be good for the engine to idle so lean.

I know this issue is similar to Wayne's thread, but it doesn't seem like he has his issue resolved either