90 740se turbo high fuel consumption LH ECU pin 30 question

[hyp2bsqr]

Hey guys I wonder if anyone knows what the purpose of the pink/white wire going from pin 30 of the ECU to the starter solenoid switch?

The symptoms are of I remove the connection my idle increases and my fuel economy improves immensely. If I leave it connected it will intermittently trip a 1.1.3 too lean code.

Any help would be greatly appreciated. I have my Bosch book on order but it would be nice to get this done before I get it

I spent a couple of hours searching so if this had been answered somewhere else please do tell.

Thanks

Fronkensteen

[mtd240]

That should be the starter service connector. It isn't supposed to be connected normally - it's for diagnostic use only (or temporary use if you have a wiring fault somewhere).

If you apply +12V to it, the starter will start the car.

Here is the wiring diagram (see page 3, B-C/2-3).

[hyp2bsqr]

Actually the connection is at 4/B on grid 4-7 and it show PNK/WHT junctioned to PNK which goes to the start solenoid switch. This is not the service connector, however the service connector does go to the same logical place.

What is the purpose of the start to ECU connection? Why would the ECU need to sense position III voltage which is only on as long as you crank the starter?

Thanks,

Hyp

[lummert]

Start signal to the ECM?

[hyp2bsqr]

I don't think so because I cut the line and it will still start just fine. Maybe like an electronic choke? I dunno, but I would sure like to know if I can just shunt it with a toggle switch:-/

[hyp2bsqr]

Could the TPS adjust be off?