PDA

View Full Version : Runs rich til boosted - FPR, Leaking Inj etc?



ricekikr
03-08-2015, 07:43 AM
Has anyone have an FPR fail cause it to run rich? I think mines stuck closed til boosted. Haven't done fuel pressure check yet.

Mine runs so rich that at WOT around 3krpm itl bog and max out AFR gauge (can only display up to 11). Probably also the reason why my plugs foul so quickly. Before I gapped my plugs (.26 before, now .34), it was misfiring causing it not display proper afrs (shows lean when rich) until I boost it, with .26 gap afr was around 14 warm-idle, with .34 its 11-12 warm-idle.

With .26 gap the misfire wasn't even that bad, it was just the occasional hiccup/hesitation. With the .34 gap it doesn't misfire = shows proper AFRs.

The only thing that seems to work is a single boost run, AFRs goes to the proper levels. .34 plug gap 14-15afr warm idle, 14-15afr part throttle, 13.5afr WOT 0psi.

Boost run = increase rpm slowly til around 5k, then floor it.

I don't think it's the wideband sensor (displays super rich that coincides with the bog) or tune/ecu adapt (stock ecu warm-up maps were zeroed out for testing - before it even occurred to me to check the inj duties)

Some data:
AEB - stock ecu+ piggyback - running open loop.
stock 4bar fpr
870cc
Mafless

Logs from Vagcom and piggyback
CTS - 189F
IAT - 100F

Pre-boost
3000rpm
0psi
Throttle - 100%
Inj Duty around 9%
Pegged gauge
Car bogs


2500rpm
Throttle - 8%
Inj duty 4%
AFR 12.5

Idle
Inj duty 1%
AFR 11.5


After boost run
3000rpm
0psi
Throttle - 100%
Inj Duty around 9%
13.5 afr til it sees boost then richens as tuned.

RPM - 2500
Throttle - 8%
Inj duty 4%
AFR - 15.2

Idle
Inj duty 1%
AFR 14.5

ricekikr
03-08-2015, 08:02 AM
other info:

Cold Voltage (running engine) 13.2 volts
Warmed up - 12.6-12.8volts

N80 disconnected - this thing caused the engine to stall in the middle of the road a couple years back.