Help on Running Lean.

[PhilW]

Had my car on the rollers yesteday and pulled a miserable 212bhp/272lbs/ft of torque on a k03s, where previously i pulled 227bhp/253lbs/ft torque on a k03.


Now something funny was happening between 4-5k, the car was smoking a lot, mixture of grey and blue smoke and didnt make the power.


Here are the logs, but they look fine to me, 183g/s, nice WG duty etc... until i done the ross tech A/F ratio calculator and see the below...

Group A:	'002				Group B:	'020				Group C:	'118			
	RPM	Load	Inj. On Time	Mass Flow		Idle Stabilization	Idle Stabilization	Idle Stabilization	Idle Stabilization		RPM	Temperature	Load	Absolute Pres.
TIME					TIME					TIME				
STAMP	 /min	%	 ms	 g/s	STAMP	 CF	 CF	 CF	 CF	STAMP	 /min	°C	%	 mbar
0	1320	86.5	9.02	23.39	0.5	0	0	0	0	1	1320	20	100	1200
1.56	1320	85.7	9.02	22	2.15	0	0	0	0	2.7	1560	21	100	1250
3.2	1680	96.2	10.25	31.56	3.7	0	0	0	0	4.2	1920	21	100	1390
4.7	2000	108.3	11.07	43.72	5.21	0	0	0	0	5.7	2240	21	100	1700
6.2	2400	151.1	16.81	72.14	6.7	0	0	0	0	7.21	2680	23	83.9	2390
7.7	2800	191.7	22.14	107.92	8.26	0	0	0	0	8.86	3040	24	80.4	2540
9.4	3200	191.7	23.78	120.78	9.9	0	0	0	0	10.42	3400	26	76.9	2540
10.9	3520	191.7	23.78	142.06	11.39	3	0	0	3	11.89	3680	27	71.4	2540
12.4	3800	191.7	23.78	150.08	12.89	3	0	3	3	13.41	4000	30	61.6	2530
13.89	4080	180.5	21.32	133.81	14.41	3	0	3	2.3	14.91	4240	30	57.3	2190
15.5	4320	169.2	20.09	141.31	16.06	2.3	0	2.3	2.3	16.6	4560	32	57.3	2160
17.1	4680	170.7	20.5	152.86	17.59	2.3	0	2.3	2.3	18.1	4880	33	58.8	2130
18.6	5000	169.2	20.5	157.14	19.1	1.5	0	2.3	1.5	19.6	5200	35	60.8	2060
20.1	5280	166.9	20.09	169.25	20.61	3.8	0	1.5	1.5	21.1	5480	37	61.6	2030
21.61	5560	159.4	19.27	169.56	22.2	3.8	0	1.5	0.8	22.77	5760	39	63.5	1970
23.3	5880	155.6	19.27	175.19	23.8	3.8	0	0.8	0.8	24.3	6080	41	66.3	1910
24.82	6160	152.6	18.45	179.5	25.3	3	0	0.8	0.8	25.8	6320	43	69.4	1880
26.3	6440	147.4	17.63	181.39	26.8	3	0	0.8	0	27.3	6640	45	71.8	1860
27.8	6720	144.4	17.22	182.97	28.31	2.3	0	0	3	28.82	6880	47	75.3	1830
29.41	6960	137.6	16.4	183.75	29.97	2.3	0	5.3	3	30.52	7080	48	0	1690
31	6200	7.5	1.23	7	31.51	0	0	0	0	32	4480	39	0	1090
32.5	3840	8.3	0	6.42	32.99	3.8	0	3.8	3.8	33.49	4240	37	0	1310
33.98	3480	8.3	1.23	4.81	34.49	0	0	0	0	35	2240	35	0	1070

RPM	Load %	A/F ratio

1320	86.5	17.36
1320	85.7	16.33
1680	96.2	16.12
2000	108.3	17.32
2400	151.1	15.52
2800	191.7	15.03
3200	191.7	13.69
3520	191.7	14.64
3800	191.7	14.33
4080	180.5	13.29
4320	169.2	14.08
4680	170.7	13.78
5000	169.2	13.25
5280	166.9	13.80
5560	159.4	13.70
5880	155.6	13.38
6160	152.6	13.68
6440	147.4	13.85
6720	144.4	13.71
6960	137.6	13.98

I've suspected its valve stem oil seals as compression is fine and i get blue smoke after overun e.g goin down a hill in gear then puttin my foot back on the accelerator, but could i check anything else? Shitted up lambdas? Vac leaks?


Any help would be good.


Thanks.

 

[Havok316]

Sounds like oil stem seals. This happened once on my old car.

 

[PhilW]

I'm pretty sure thats it, as i was constantly topping up with oil when my last turbo died for a while til i sotrted out a new turbo.

Theres new plugs in the car as well btw

 

[PhilW]

bump.

 

[Havok316]

Yea my astra coupe drank oil like a kid with coke. Almost a full bottle of Castrol GTX every 2/3 months (the largest one which is 4.6L ?!?!) and no oil patches showed under the car ever! even the garage i took it too said they couldnt see an oil leak either so they did the stems and all was fine

 

[ibizacupra]

done a compression test?
rings spring to mind.. if oiling up on overrun.
stem seals will puff oil out on cold start but go away unless very knackered. (or could be both)

 

[m0rk]

does the rosstech calculation of a/f ratio take into account the 4 bar FPR squirting more fuel in?

 

[PhilW]

I've done the rosstech calculation and it was seeing mid-low 12's on stage 2, which from my understanding it spot on under boost.


I've done a compression test about 3 weeks ago and it was showing 180's on all cylinders.

What else would cause it to run lean? I went into limp mode about a week ago after melting my N112, replace the fuse and cleared the codes, worth disconnecting the battery to remove adaptions?

 

[Daz_gibbo]

It should do Mork as it uses injector period(ms) which should be altered in Revo stage 2 code for the 4BarFPR

 

[cuprabaz]

Could you have over filled the oil, may sound silly but that'll cause it to smoke.

 

[PhilW]

Nah its the opposite baz, always running low coz its burning oil off.

Its only started running lean recently for some reason.

 

[Forbez]

Thats good oil your burning up there too!

 

[PhilW]

Yeah thanks for that tom. lol.

I've had a look round for obvious things, vac leaks etc.. cant find anything.

I'm stumped really, would it have anything to do with me melting my N112 driving 10 miles then replacing with a resistor, 330ohm 10 watt?

 

[PhilW]

Ok, gonna check/do the following...


Disconnect battery
run injector cleaner
check vac lines/boost leaks
change oil and replace oil filter with OEM one
clean PCV/breather pipework to catch tank
check manifold bolts
replace fuel filter
check injectors and other fuelling parts


Anything else i can do?


If this was a thread on strange boost or a misfire i'd have 4 pages by now... lol.

 

[PhilW]

bump.

 

[beattie17]

What was the outcome of this?

 

[PhilW]

Lol. It wasnt running lean, if anything is was pretty much spot on. Those A/F figures dont take into account the 4bar which throws in 13.5% extra fuel iirc.


But, the reason it was running ****, as i guess, was down to stuffed valve stem oil seals, slight wear in the bores (not enough to cause low compression) and worn wrist pins.

Had it rebuild with standard bore JE pistons and Scat rods and its better than before.

Will hopefully have a power figure for it on saturday.