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2009 Impreza Diesel accelaration problem

('09-'13) 
5K views 6 replies 4 participants last post by  SID-a 
#1 ·
Hi Guys!

I'm new to this forum and was looking for a help with a problem I am having with a EE20 Impreza diesel engine here in the UK.

The issue I am experiencing is
bad MPG's compared to what it used to be like
and also under hard acceleration the engine appears to have a flat spot around 2300-2500RPM to the point it feels like I have applyed the brakes. This is only really apparent in 2nd and 3rd gear.
I have inluded some graphs of me accelarating from 1st to 2nd then to a standstill again if these graphs help any.
Any help would be appreciated

Thank you






 
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#2 ·
I'd really like to see graphs against time tbh, and units for rail pressure.

areas to look at-
boost control (it's holding at full boost but is it slow to rise?)
Rail pressure- is it tracking requested/ slow to rise/ overshooting?
MAF- is it plausible?

But patience for the next recalibration/learning cycle(or an enforced pump and injector learning at the dealers) might cure it. y old one would feel very odd just before it needed to do a pump learn...
 
#3 ·
Hi dpm thanks for replying!

I've got some graphs for you here as requested, does this help at all?

Starting up the car, sometimes feels like it takes a while to start.





Boost seems ok looking at this graph 1st to 2nd gear





You can see the dip in both of these next graphs where the car looses power.









Final graph shows the car at a constant 1,500rpm seems quite a bit of variation, is this normal?



 
#4 ·
that's a big dip for sure. But working out cause and effect might take some work...

Is the fuel filter fresh?

Might try disconnecting the battery and restarting, see if it'll force relearning.

Log boost actual vs requested, rail pressure actual vs requested, MAF. try a 2nd gear pull from idle to redline for each so we can overlay them.
 
#5 ·
Hi DPM

I had to order a fresh filter and I've only got round to changing it today.
Ok so I changed the fuel filter within the engine bay and also pulled the battery, it still has this dip in second gear.
What software are you using to request actual vs given readings?

Also I disconnected the MAF, but it acts like its in limp mode so I can't test it very well.

Thanks
Ross
 
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