Warning light & MAF

[Cupra Ross]

If its going to split on the underside one, it'll split quite close to the manifold. I had to remove the N249 and N112 retention assembly on the LC to get to mine but the LCR doesn't have this afaik.

Log blocks 115 and 118. 118 has the boost duty cycle (the N75 requests sent from the ECU) and 115 has specified vs actual boost. When more boost is requested in block 115, you should see the boost duty cycle numbers getting close to 100 in block 118.

The fact that you're getting induction noise suggests that the turbo is spooling but the charge air is being lost somehow. If you don't have split hoses or a sticky dump valve, it must be going out the wastegate. I'd suspect that the N75 is past its best and isn't reacting quick enough to the ECU command for more boost by closing the wastegate.

 

[skahigh]

If its going to split on the underside one, it'll split quite close to the manifold. I had to remove the N249 and N112 retention assembly on the LC to get to mine but the LCR doesn't have this afaik.

Log blocks 115 and 118. 118 has the boost duty cycle (the N75 requests sent from the ECU) and 115 has specified vs actual boost. When more boost is requested in block 115, you should see the boost duty cycle numbers getting close to 100 in block 118.

The fact that you're getting induction noise suggests that the turbo is spooling but the charge air is being lost somehow. If you don't have split hoses or a sticky dump valve, it must be going out the wastegate. I'd suspect that the N75 is past its best and isn't reacting quick enough to the ECU command for more boost by closing the wastegate.

Thanks Ross, I'll do some logging later today or on the weekend. It's weird that it only happens when cold though isn't it?

 

[Cupra Ross]

Its one of those more annoying aspects of the 1.8Ts character, thats for sure. One thing I've noticed is that it doesn't seem to happen on cable throttle versions of this engine. I had the AEB variant 1.8T in my Passat and it was smooth as silk hot or cold. Co-incidentally, these don't have an N249 either. Possible connection???

 

[skahigh]

Here is my logs, its a third gear run into 4th at the end.

Friday	17	April	2009	11:51:04											
1ML 906 032 		1.8l R4/5VT         0001													
															
	Group A:	'002				Group B:	'115				Group C:	'118			
		RPM	Load	Inj. On Time	Mass Flow		RPM	Load	Absolute Pres.	Absolute Pres.		RPM	Temperature	Load	Absolute Pres.
	TIME					TIME					TIME				
Marker	STAMP	 /min	%	 ms	 g/s	STAMP	 /min	%	 mbar	 mbar	STAMP	 /min	°C	%	 mbar
	299.28	2240	14.3	0	6.42	298.39	2320	16.5	1000	1010	298.88	2280	14	0	1010
	300.6	2240	95.5	9.86	47.53	299.68	2160	15	1000	1010	300.1	2200	14	95.3	970
	301.81	2680	157.9	13.26	94.14	301	2360	111.3	1990	1260	301.4	2480	14	95.3	1470
	303.22	3400	191.7	16.32	126.33	302.21	2800	191.7	2060	2220	302.71	3120	15	61.2	2370
	304.52	4120	191.7	16.32	162.56	303.72	3680	191.7	2240	2220	304.12	3880	14	65.5	2280
	305.73	4760	191.7	16.32	184.75	304.92	4320	191.7	2280	2230	305.33	4520	15	66.3	2260
	307.03	5400	191.7	15.64	209.28	306.13	4960	191.7	2260	2270	306.63	5280	18	68.6	2240
	308.24	5920	191.7	15.98	216.69	307.44	5560	191.7	2200	2190	307.84	5760	20	69	2190
	309.56	4800	115	13.26	136.19	308.66	6080	188.7	2090	2140	309.16	5680	21	0	1700
	310.85	5160	191.7	17.34	209.86	310.05	4920	191.7	2220	2410	310.45	5040	22	76.9	2410
	312.16	5520	191.7	16.66	213.61	311.25	5280	191.7	2250	2340	311.67	5360	24	72.5	2270
	313.38	5800	191.7	17.68	217.39	312.56	5600	191.7	2220	2250	312.96	5720	26	71.4	2230

 

[Cupra Ross]

Very nice log mate, nothing wrong with MAF or N75 from looking at that. Your car looks to be pulling about 275bhp. Which map is that?

 

[Rocky Rocastle]

i just see all that and think.....eh?????

i'd love to get my head round what it all means, need a cable though first but then im stumped with which ones will be duff when purchased from the bay. I'm not very car or pc literate shall we say !

 

[skahigh]

Very nice log mate, nothing wrong with MAF or N75 from looking at that. Your car looks to be pulling about 275bhp. Which map is that?

It's been rolling roaded at 262 mate and the map is custom code, although that was before I changed the TIP and boost hoses etc.

Unfortunately, I don't think there is anything wrong with it under normal conditions, it just gets a little strange occasionaly when cold and on part throttle in second gear mainly.

 

[Cupra Ross]

I'd say 262 was very conservative mate. General rule of thumb for a rough bhp figure is peak mass airflow in g/s divided by 0.8

Try logging 2 blocks at a time instead of 3. You get a better sample rate that way, sometimes as much as twice a second instead of once every 1.2 seconds. It looks like a progressive map as your N75 cycle is quite low on spool up. All hell seems to break loose after that though, it must be very swift indeed.

It could be a characteristic of the map that it just needs to be warm. I wouldn't be complaining with those logs though

 

[traumapat]

why not try dielectric grease? its only pennies.

i had cold start issues , poor idle, hesitation. car fine after it had warmed up. logged the maf on idle and the figures were eratic.

i think moisture/condensation was occuring around the electrical prongs on the maf connector hence it clearing once burnt off. packing the connection with dielectric grease protects it from any air or moisture.. so it stops it getting affected.

after 2 days the car had settled and was much smoother on cold start.

worth a punt at 2.99 a tube or whatever

 

[Cupra Ross]

Excellent idea Pat, definitely one to try.

 

[skahigh]

good idea pat, I'll give that a go. Where do you buy it from?

 

[traumapat]

http://www.seatcupra.net/forums/showthread.php?t=101577&highlight=dielectric

have a read through... last few pages give ideas on where to get it .
i got mine from ebay.

 

[Cupra Ross]

http://www.maplin.co.uk/Module.aspx?ModuleNo=29006&doy=18m4&C=SO&U=strat15

 

[skahigh]

Nice one guys

 

[traumapat]

hang on that looks like a spray.

this is the stuff you want
http://cgi.ebay.co.uk/Dielectric-Gr...14&_trkparms=72:1683|66:2|65:12|39:2|240:1318

its a gel you need.. this takes up the space where any air would usually sit. the spray would only coat the the connection. (and possibly run where you dont want it to go)

 

[Cupra Ross]

hang on that looks like a spray.

this is the stuff you want
http://cgi.ebay.co.uk/Dielectric-Gr...14&_trkparms=72:1683|66:2|65:12|39:2|240:1318

its a gel you need

It is a gel, 50g comes in a tube, 70g in an aerosol, its the same stuff though.

 

[traumapat]

It is a gel, 50g comes in a tube, 70g in an aerosol, its the same stuff though.

should be ok then

 

[skahigh]

do you just pack it into the plug, reconnect it and wipe off the excess or should I use it sparingly?

 

[traumapat]

from memory theres 5 holes, squeeze in liberally

 

[skahigh]

Right, have been to Maplins, bought the grease, applied liberally and been for a test drive. Part throttle feels very smooth but I guess only time will tell whether this has actually solved my problem.