Timing pull and injector duty cycle

[8bit]

Got this in my RR thread but posting it here for more visibility.

Car spec is mk1 LCR, Revo stage 1, Forge FMIC, BMC twin-cone filter, Badger5 v2 TIP. Revo settings at the time the logs were taken were boost = 6 and timing = 4.

Before I fitted the FMIC I got minimal timing pull and only at the top end with these settings but since fitting it I'm seeing the timing pull below. I also calculated the injector duty cycle (in first log) which looks a bit higher than it should be - it tries to exceed 100% at one point which is obviously not possible.

I know Revo runs a bit richer for cooler cylinder temps but should it be this high, or is this an indication of some other problem perhaps? Could that be contributing to the correction factor figures?

As far as other stuff goes, the MAF reading looks a bit low but the MAF is only maybe 7 months old. Coilpacks and plugs are about 6 months old and the plugs are NGK Iridium, grade 7. N75 is about 6 or 7 months old. Air filter is less than 2 months old.

Any help gratefully received

Saturday	22	September	2012	18:17:40:62534		VCDS Version: Release 11.11.4	Data version: 20120807									
1ML 906 032 A		1.8l R4/5VT         0001														
																
	Group A:	'002					Group B:	'020				Group C:	'115			
		Engine Speed	Engine Load	Injection Timing		Mass Air Flow		Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation		Engine Speed	Engine Load	Boost Pressure	Boost Pressure
	TIME	(G28)				Sensor (G70)	TIME	Cylinder 1	Cylinder 2	Cylinder 3	Cylinder 4	TIME	(G28)		(specified)	(actual)
Marker	STAMP	 /min	 %	 ms	IDC	 g/s	STAMP	°KW	°KW	°KW	°KW	STAMP	 /min	 %	 mbar	 mbar
	10.25	1880	59.4	5.78	9.06	23.19	10.55	0	0	0	0	9.95	1840	46.6	1000	1040
	11.16	1960	78.9	7.48	12.22	32.44	11.46	0	0	0	0	10.87	1920	71.4	1080	1130
	12.07	2080	81.2	7.82	13.55	34.28	12.37	1.5	0	0	0	11.77	2040	82.7	1120	1260
	12.98	2240	94.7	9.86	18.41	43.56	13.28	1.5	1.5	0	1.5	12.68	2160	70.7	1330	1270
	13.88	2440	127.1	12.58	25.58	66.97	14.18	3	3	1.5	1.5	13.57	2360	117.3	1960	1510
	14.79	2720	167.7	20.06	45.47	96.89	15.09	3	4.5	4.5	2.3	14.49	2600	152.6	2110	2000
	15.7	3080	186.5	22.44	57.60	107	15.99	2.3	4.5	4.5	3.8	15.39	2960	182	2210	2410
	16.6	3440	191.7	22.44	64.33	133.61	16.9	2.3	3.8	3.8	3.8	16.3	3320	191.7	2230	2400
	17.5	3800	191.7	22.78	72.14	140.86	17.81	1.5	3.8	3.8	3	17.2	3680	191.7	2250	2380
	18.41	4120	191.7	22.1	75.88	151.81	18.71	1.5	3	3	3	18.11	4000	191.7	2250	2360
	19.31	4440	191.7	21.76	80.51	162.78	19.62	2.3	3	3	3	19.01	4360	189.5	2240	2360
	20.22	4760	184.2	20.74	82.27	165.69	20.52	2.3	2.3	3	3.8	19.92	4640	187.2	2230	2300
	21.12	5040	185.7	20.74	87.11	176.81	21.44	1.5	2.3	2.3	3.8	20.82	4920	184.2	2230	2280
	22.03	5320	182	20.4	90.44	184.19	22.33	1.5	3.8	1.5	3	21.73	5240	185	2230	2230
	22.94	5560	190.2	21.08	97.67	190	23.24	0.8	3.8	1.5	3	22.63	5480	179.7	2230	2270
	23.84	5800	184.2	21.08	101.89	197.14	24.15	0.8	3	0.8	2.3	23.54	5720	183.5	2220	2180
	24.75	6000	171.4	19.04	95.20	198.92	25.06	0	3	1.5	1.5	24.45	5960	175.2	2200	2200
	25.66	6200	166.9	18.36	94.86	202.97	25.96	0.8	2.3	1.5	2.3	25.35	6160	178.2	2200	2170
	26.57	6400	170.7	18.36	97.92	204.19	26.86	0	2.3	2.3	2.3	26.25	6360	164.7	2200	2240
	27.46	6560	165.4	17.68	96.65	203.31	27.77	0	0	3.8	0	27.17	6520	167.7	2200	2130
	28.37	6480	14.3	1.7	9.18	12.31	28.67	0	0	0	0	28.08	6480	13.5	1000	1360
	29.27	6320	12.8	0	0.00	14.81	29.57	0	0	0	0	28.97	6360	12	1000	1110
	30.18	6160	12	0	0.00	14.75	30.48	0	0	0	0	29.88	6200	12	1000	1070

Saturday	22	September	2012	18:24:00:62534	VCDS Version: Release 11.11.4	Data version: 20120807									
1ML 906 032 A		1.8l R4/5VT         0001													
															
	Group A:	'004				Group B:	'112				Group C:	'020			
		Engine Speed	Battery Voltage	Coolant	Intake Air		Exhaust Gas	Enrichment Factor	Bin. Bits	Bin. Bits		Timing Retardation	Timing Retardation	Timing Retardation	Timing Retardation
	TIME	(G28)	(Terminal 30)	Temperature (G62)	Temperature (G42)	TIME	Temperature Bank 1	Sensor Bank 1			TIME	Cylinder 1	Cylinder 2	Cylinder 3	Cylinder 4
Marker	STAMP	 /min	 V	°C	°C	STAMP	°C	 %			STAMP	°KW	°KW	°KW	°KW
	11.47	2200	13.93	90	22	10.86	710	0	        	        	11.16	0	0	0	0
	12.37	2280	13.86	90	22	11.77	710	0	        	        	12.07	0	0	0	0
	13.28	2320	13.93	90	22	12.68	705	0	        	        	12.98	0	0	0	0
	14.19	2480	14	90	21	13.58	695	0	        	        	13.88	0	0	0	0
	15.09	2760	13.93	90	21	14.49	690	0	        	        	14.79	3	0	1.5	0
	15.99	3080	13.93	90	20	15.39	695	0	        	        	15.69	3	4.5	3	1.5
	16.9	3480	13.93	90	18	16.3	715	0	        	        	16.6	2.3	5.3	3	3
	17.81	3840	13.86	90	19	17.2	735	0	        	        	17.5	3.8	5.3	4.5	3
	18.71	4160	13.93	90	20	18.11	755	0	        	        	18.41	5.3	4.5	4.5	2.3
	19.62	4480	13.93	91	21	19.01	785	0	        	        	19.32	5.3	4.5	3.8	2.3
	20.52	4800	13.93	92	21	19.92	800	0	        	        	20.22	5.3	3.8	3.8	1.5
	21.43	5080	13.93	92	23	20.82	820	0	        	        	21.12	4.5	3.8	2.3	1.5
	22.33	5320	13.93	92	24	21.73	835	0	        	        	22.03	3.8	3	0.8	0.8
	23.24	5600	13.93	92	24	22.65	845	0	        	        	22.94	3	3	0	1.5
	24.14	5840	13.93	92	26	23.54	855	0	        	        	23.84	2.3	3	1.5	1.5
	25.05	6040	13.93	92	27	24.44	865	0	        	        	24.76	2.3	2.3	0.8	0.8
	25.95	6240	13.79	91	28	25.35	875	0	        	        	25.66	1.5	3	0	0.8
	26.86	6400	13.86	90	29	26.25	885	0	        	        	26.56	1.5	2.3	3	2.3
	27.76	6600	14	90	30	27.17	895	0	        	        	27.46	1.5	2.3	4.5	3
	28.68	6440	14	90	27	28.08	905	0	        	        	28.38	0	0	0	0
	29.58	6280	14	90	27	28.98	905	0	        	        	29.27	0	0	0	0

 

[8bit]

Bump - anyone?

 

[Dan1720v]

From memory, 6 was the 'accepted' amount of pull.

 

[8bit]

Yeah cheers, I remember reading that in the Revo SPS guide. To my mind though, any more than just a little bit at the very top end or on the overrun is a symptom of the ECU pulling it back because the engine isn't able to sustain what's being asked of it.

But the main point is that I was getting far less timing pull before fitting the FMIC. I'd have thought if anything I'd have less pull and be able to advance timing a touch. I've also got this excessive injector duty cycle too, so for some reason the ECU is trying to add more fuel than the system can deliver.

 

[wild willy]

Look at your exhaust gas temperature its very high. At 930 degrees plus I believe the ecu adds fuel to cool things down. Considering the measurement you are seeing is made by the lambda sensor that's downstream of the true egt probe in the exhaust turbo turbine housing I,d say there is a problem there. E

 

[virdi]

To get the best out of what you have, ideally you need a custom map.?

 

[8bit]

Look at your exhaust gas temperature its very high. At 930 degrees plus I believe the ecu adds fuel to cool things down. Considering the measurement you are seeing is made by the lambda sensor that's downstream of the true egt probe in the exhaust turbo turbine housing I,d say there is a problem there. E

The EGTs are the same as before I fitted the FMIC though, and the logs I did before that showed very little timing pull. They're also slightly lower at high RPMs than before I got the car mapped. I agree to an extent though, 900C is pretty toasty but those temps aren't really any worse than any other logs I've seen.

Not sure what you mean re. the temp readings, are the ones that VCDS logs not just from the EGT sensor itself? In any case, you can see the column after the temps shows the enrichment factor, this is how much fuel the ECU is adding to bring cylinder temps down. It's showing zeros right down so the ECU isn't reaching that threshold. I've got another log somewhere from before it was mapped that shows temps hitting 920 and you can see the ECU adding fuel by the enrichment factor.

To get the best out of what you have, ideally you need a custom map.?

Ideally yes, but I live in Scotland, specifically the arse-end of nowhere in Scotland, we're not exactly tripping over really good custom mappers here

 

[Ronin225]

Just a thought, the whole intake system has been heavily upgraded with TIP's, filters, etc however the exhaust side is standard
Is the engine consuming much more than usual and unable to get rid of it as quickly as it can be taken in

 

[8bit]

Could be I guess, seems a bit strange that it would show worse CFs after installing the FMIC tho, and could that explain the excessive injector duty?

 

[ibizacupra]

more denser air charge now.... presuming the fmic is delivering the same volume of air, and is flowing well with minimal pressure drop across it compared to previous setup?

not all fmic's work well....

any oil in your pipe to throttle body? have a look see...

 

[virdi]

Bill - Should logging ideally be done 'on the road' - rather than rollers?


Thanks

 

[wild willy]

Its interesting that your version of vagcom lists the sensor responsible for delivering a measurement in the header column. Regarding channel 112 (egt) i can't see what sensor its displays as being responsible for its measurement.
If it displays G130 or G39 its derived from lambda sensor.....
but if it displays G235 the temperature is indeed a true egt measurement in the turbine measured by the exhaust gas temperature sender. Could you check please.

 

[8bit]

more denser air charge now.... presuming the fmic is delivering the same volume of air, and is flowing well with minimal pressure drop across it compared to previous setup?

not all fmic's work well....

any oil in your pipe to throttle body? have a look see...

Thanks for the input Bill. I always thought (or assumed) that decent FMIC = lower IATs = lower CFs? I can kind of see what you mean though. If that's the case then am I just running too much timing and/or boost? As Ronin suggests, would a larger downpipe and sport cat or decat help?

The FMIC is a Forge one, btw. I'll check the throttle body at the weekend.

Bill - Should logging ideally be done 'on the road' - rather than rollers?


Thanks

Bill will know for sure but I'd have said better on the road - the fans on most dyno setups aren't likely to be moving as much air over the front of the car as it'll get on the road when moving at speed.

Its interesting that your version of vagcom lists the sensor responsible for delivering a measurement in the header column. Regarding channel 112 (egt) i can't see what sensor its displays as being responsible for its measurement.
If it displays G130 or G39 its derived from lambda sensor.....
but if it displays G235 the temperature is indeed a true egt measurement in the turbine measured by the exhaust gas temperature sender. Could you check please.

It's not my vagcom, it's a friends. Just looked at the original log file but it doesn't say. I'll ask him to check next time I see him.

 

[wild willy]

No problem it may not say.

Are you sure you haven't filled up somewhere different or mistakenly filled up with 95 RON instead.

 

[8bit]

No problem it may not say.

Are you sure you haven't filled up somewhere different or mistakenly filled up with 95 RON instead.

I haven't used anything other than Shell for ages, and I'm always super-careful to get the right pump now that they sell V-Power diesel

Found an old log of block 120, this was on the stock map. EGTs are a fair bit higher and you can see the enrichment factor kicking in as the temps hit 920. This was done with the same version of VAGCOM. If the enrichment kicks in about 920 then I'd say we can assume that VAGCOM reads EGTs from the sensor rather than the lambda, or the enrichment would appear at lower EGTs (because the lambda temp will be lower than turbine outlet):

Exhaust Gas	Enrichment Factor
Temperature Bank 1	Sensor Bank 1
°C	 %
655	0
650	0
650	0
655	0
670	0
690	0
720	0
765	0
790	0
820	0
825	0
840	0
850	0
865	0
875	0
885	0
895	0
900	0
910	0
920	2
935	8.6
945	16.5
945	18.4
925	12.2
915	6.7
915	7.8
925	12.2
925	0
910	0
880	0
825	0
805	0
785	0

 

[wild willy]

I've never seen added fueling on a log before that's really interesting thanks.
I'd have to agree if thats the case then the the temps shown must be from the exhaust gas temp sender in the turbo and not from the lambda sensor. Thanks for taking the time to post it.

 

[8bit]

No worries

 

[ibizacupra]

Bill - Should logging ideally be done 'on the road' - rather than rollers?


Thanks

I do it on the rollers, because I have them, and its a far safer environment to log a lot of things

road logging is reliant on what you can view in vagcom - its better than nothing but not as comprehensive as on a dyno where you see real time power/torque boosts >1.5bar, afr's temps etc etc etc + vagcom or Me7 logger info...

 

[ibizacupra]

I've never seen added fueling on a log before that's really interesting thanks.
I'd have to agree if thats the case then the the temps shown must be from the exhaust gas temp sender in the turbo and not from the lambda sensor. Thanks for taking the time to post it.

the std threshold is 920c for the fuel dump on egt

 

[8bit]

Actually, would a 4 bar FPR help?