Nodge68
Well-Known Member
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- 32,504
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- Near Newquay
Hi Nodge
View attachment 106197 View attachment 106198
Best to Backprobe ECU 25 (the TPS switch - digital 0 and 12v on or off)
Would also look at 37 for the variable TPS wiper signal post 9 degrees tps.
Only if those are stable would I then look at the dual fuel quantity servo output to the VP37 with a scope (12V PWM - on pins 1 and 2) and also the quantity feedback from the vp37 on pin 14 (0-5V analogue ecu input- (this is possibly AC - I have not checked)
The other ends of the quantity feedback are a 0-5v (21) analogue output from the ecu and a 5v reference. (39)
It is interesting that this design of fly by wire tps is NOT the normally seen dual opposing track design. It is a sinlge wiper design backed up by the tps idle switch. Quite robust really. In the event of an issue the release of the throttle should stop signal the ecu to ignore the signal from the wiper. As the switch is opened as the throttle moves past 9 degrees the scu checks for a plausible signal (it is only in the context of the values immediately after and immediately prior to switch activation though.
The pump may be the actual culprit once the tps has been ruled out - if it is the tps it will be the switch which is a two minute check with a backprope and ground.
Pump wiring can be an issue and should be checked carefully. Also check the wiring very carefully around the quantity position servo output as it may have had an evry mod in the past which taps two of the wires.(the yellow/black stripe and red) - the connectors have also occasionaly had issues. Again that circuitry inside the pump is very very robust and any issues tend to be woring related.
Hope that helps.
This is really one of those jobs where a live data stream would be invaluable and be able to pinpoint the issue extrmely quickly. Bit of a bu€€er about the i930
Joe
Cookl.
Thanks Joe.
I'll get Luke back up here so I can test those. Be after the holidays now mind, if Luke is ok with that?
