Hi Crasher
Hope you're well.
Yeah - that definitely seems to be one of the things to check...one of the other suggestions seem to be:
- Faulty MAP
I managed to get hold of an OBD scanner to measure some data. I took some MAP readings, and fuel trims for different RPMs.
1. MAP data
(i) before turning the engine on - reads 14.5psi which seems about right when compared to today's atmospheric pressure which was around 14.6psi
my thoughts: MAP sensor is ok.
But are there any other readings/tests I can do to confirm if the MAP is definitely ok? maybe compare how the MAP varies with load factor and throttle position %?
2. Fuel Trim Data
(i) I took the Short Term and Long Term fuel trim % values over time (car stationary and just held different rpm constant for around 30 secs). You can see the results below..
IDLE -
Attachment 36870
1500RPM -
Attachment 36866
2000RPM - about 30 secs
Attachment 36867
2500RPM - about 30 secs
Attachment 36868
3000RPM - about 25 secs (RPM dropped automatically to idle before 30 secs)
Attachment 36869
Observations:
- Long Term Fuel Trim is +11% or thereabouts.
- Short Term Fuel Trim is moving around a bit:
at idle it seems within acceptable level
mid rpm (1500 and 2000): starts to get a little worse (more negative) with higher rpm
at the high rpm (2500 and 3000): seems to be within an acceptable level again.
I'm not entirely sure what to make of it?
p.s. I am very new to all this but quite happy to learn/research as I go along.