Porsche Repair: 85/2 944 surges and numbering question, turbo air flow, haynes repair manual

Question
Hi Dave!
My 1985/2 944 surges when I hold the accelerator steady. It used to only go up to about 1250 RPMs but I've done some work so that it will reach almost 4000 at times. I have checked my injectors, replaced oxygen sensor, had all vaccum leaks checked for, and the airflow sensor replaced. My real question and concern is about the airflow sensor which has been what most say is the problem. So I replaced it. In referring to the Haynes repair manual they reference to non-turbocharged vehicles as having port numbers as such as 12, 8, etc. (these numbers are found on the top of the sensor on the black male end of the connector). But turbo vehicles are referred to with the designation 1, 2, 3, 4. My car has those apparent turbo numbers even though it is not and never was a turbo model. These numbers were on the old sensor and the new one. The history of this car is hazy so the sensor could already have been replaced without my knowledge. Could this be an error on Haynes part or do I need to find a correct sensor? If it is correct, what do I need to do? I'm at the end of my rope of options. Thank you very much!

Answer
Hi Eric,

As for the turbo vs non-turbo air flow meter, I doubt Haynes would make that kind of mistake.  I checked to see what would happen if I tried to buy an air meter and it seems pretty hard to buy the wrong one...so I imagine what you've got is fine.

As for the numbering, let's work at the problem the other way.  Check out the wiring diagrams on pages 213 and then 203 of your Haynes manual.  Regardless of the year it appears that your non-turbo should have four wires.  Does it?  Can we get to the bottom of the numbering issue by comparing wire colors or the sequence of the wire from the diagrams to the real part?

Let me know if you think that could work.

Dave