Not showing Full throttle on M52B28 conversion

Mon Jul 10, 2017 5:08 pm

Hi

I transplanted a M52B28 motor from a UK E36 into my E30 and am now about to tune it with the Unichip.
I noticed 2 things:
My Diagnostic tool does not show me FT on the Dyno. The Throttle valve opens fully.
Vanos is permanently Retarded- The Vanos I can control with the Unichip

The Tps shows:
0.67 V at idle
4.47 V a
@ WOT or Full Throttle
Are these values correct or am I barking up the wrong tree ?

I removed the ASC valve (throttle blade assembly), as I only got the Siemens DME with the motor. EWS was cancelled.

Could it be that the DME does not see the ASC be the reason that my throttle opens fully by wire, but the ECU does not want to process the info ?

Or what would be the proper way to adjust that?

Mon Jul 10, 2017 9:14 pm

5v is a common max voltage for engine sensors so sounds about right

Tue Jul 11, 2017 7:45 am

So why is the ECU not seeing Full Throttle ?
And what can I do to fix that ?

Tue Jul 11, 2017 1:43 pm

Maybe the tps needs adjusting

Tue Jul 11, 2017 2:04 pm

From what I see and can glean from Google, this TPS cannot be adjusted.
I am not sure how to check it ?
Weird thing is the DME seems to see WOT at very low RPM and then at high RPM.
Almost as if it were running closed loop, and therefore too lean, when the Vanos should be advanced.
I am busy mapping my Vanos switch points right now and maybe the DME will show Full Throttle once the cam angle sensor gives the DME the values it wants ???

Tue Jul 11, 2017 6:59 pm

I think the tps mountings are oval from memory, I know they are a common failure on S50 engines also

Wed Jul 12, 2017 7:56 am

I have a feeling the TPS is OK, as it gives me a nice smooth sweep.
a new FEBI unit gives similar, albeit lower values at WOT.
It is really flummoxing why the DME does not see wide open throttle from 1500 to about 4000 RPM ?