turbo and smoke issue yet again - Page 4

Woodsman · 22-05-09, 04:00 AM

Quote:

Originally Posted by Martc

Sounds like the air mass meter?

FFS why didn't anyone think of that before

Would also agree with gaz oil could be a factor, but if its u/s anyway a clean with some carb cleaner aerosol can't hurt, I have known it to work on several occasions

Best of luck

20vcqdriver · 22-05-09, 07:29 AM

Yep went to the expense of fitting a new MAF.
K&N's are fine until they are cleaned and people over oil them and then the excess ends up on the measuring wire of the MAF.
Used a small intercooler last year, this new charge cooler is slightly bigger but uses water not air to keep the intake air temp low so am not able to swap back and having tested both on the bench the Charge cooler is 100% more efficient.
Now looking at the knock sensors. This is one item that would cause limp mode and no fault code. Replaced them last year but have had new parts fail before......just spent 1.5 hrs fitting a new encoder to a motor here at work yesterday and it lasted 3 hours

2nd new one still going strong.

Woodsman · 22-05-09, 10:32 AM

Sorry forgot to mention, rather than plugging in vagcom after a run. If you can drive the car with it connected while someone watches and saves the live data. You will be able to see what the ecu is seeing when it decides that it has seen a problem. watchng data while the engine is idling will confirm the sensors work, but you really want to be seeing the data in the split second before it goes limp.
I'm not familliar with vagcom but on other diagnostic programs you can watch other ecu parameters as well as sensor readings eg;

Measured airflow vs calculated airflow, is a good one for checking MAF

Actual boost pressure vs boost requested and N75 duty cycle can be helpfull.

Ignition angle + knock correction factor, some ecus will calculate this (and show you) seperatly for each cylinder, can be very helpfull.

Hang in there, Can't be much left it can be
Ps didn't mention the diagnostic conector, if its still in the fuse box you will need to relocate, extend etc

20vcqdriver · 22-05-09, 02:15 PM

Quote:

Originally Posted by Woodsman

Sorry forgot to mention, rather than plugging in vagcom after a run. If you can drive the car with it connected while someone watches and saves the live data. You will be able to see what the ecu is seeing when it decides that it has seen a problem. watchng data while the engine is idling will confirm the sensors work, but you really want to be seeing the data in the split second before it goes limp.
I'm not familliar with vagcom but on other diagnostic programs you can watch other ecu parameters as well as sensor readings eg;

Measured airflow vs calculated airflow, is a good one for checking MAF

Actual boost pressure vs boost requested and N75 duty cycle can be helpfull.

Ignition angle + knock correction factor, some ecus will calculate this (and show you) seperatly for each cylinder, can be very helpfull.

Hang in there, Can't be much left it can be
Ps didn't mention the diagnostic conector, if its still in the fuse box you will need to relocate, extend etc

Interesting, will ask the question to Tim, Diagnostic connectors are now in the glovebox so no problem there.

20vcqdriver · 22-05-09, 06:10 PM

At last I can enjoy the homefry to the full after checking the knock sensors, one was loose. Tightened to 20nm and off down the road, let the engine oil warm up and booted it. Back is the quick spool up and gone is limp mode. What a difference a knock sensor makes. Just clocked a 2.5 sec 50-70mph in 3rd which is plenty quick enough for me.....at the moment.

With any luck the 2.75" exhaust in July will get me a bit more over this 7A 2.25" system.
Thanks to everyone for the help and advice. One to remember for the future.

Megsy · 22-05-09, 07:33 PM

Glad to see its sorted Dave.
Was wondering how you have got engine to 300bhp with just chips?

20vcqdriver · 22-05-09, 07:56 PM

Also has a semi ported head and a chargecooler that even after my fast blast tonight was still cool on the outlet side, with this and the 2.75" exhaust and no cats these engines have been known to push out 297bhp. Once exhaust on I'll be off to a rolling road to see exactly what it is producing. Just removing the cats can get you 10 to 15bhp, my head work at worse is 5bhp and Paul Nugents 1.4bar chips with matching MAP sensor does the rest.
Massive torque is more impressive with 60 to 80 in 5th in 4secs dead (I have the 6 speed gearbox) 1st pretty pointless unless I try towing a tank!
As for fuel consumption well lets just say 'horrific' when the foot is down...

Already sourced a new block that will be built with stronger rods and bearings to take the new turbos torque, ......once you start its hard to stop..

but I am not rushing it'll be 2+ years in the making...

Coxy · 22-05-09, 08:02 PM

glad to see it's sorted! Now you can change you're signature!

Emjay · 22-05-09, 08:25 PM

well done Dave, really pleased for you fella. I know how frustrating these things can be from personal experience. Now go enjoy for a while

Megsy · 22-05-09, 09:33 PM

Quote:

Originally Posted by 20vcqdriver

At last I can enjoy the homefry to the full after checking the knock sensors, one was loose. Tightened to 20nm and off down the road, let the engine oil warm up and booted it. Back is the quick spool up and gone is limp mode. What a difference a knock sensor makes. Just clocked a 2.5 sec 50-70mph in 3rd which is plenty quick enough for me.....at the moment.

With any luck the 2.75" exhaust in July will get me a bit more over this 7A 2.25" system.
Thanks to everyone for the help and advice. One to remember for the future.

Cheers Dave was just wondering.I put 20v rr into my ur and am also using a chargecooler.chips are 270bhp with external waste gate.I will be doing the same to my lump once I've bought all of the bits.

22-05-09, 07:29 AM	#32
20vcqdriver 4 ring whore! Classic Audi Club Member Join Date: Dec 2007 Location: Wirral Posts: 3,910	Yep went to the expense of fitting a new MAF. K&N's are fine until they are cleaned and people over oil them and then the excess ends up on the measuring wire of the MAF. Used a small intercooler last year, this new charge cooler is slightly bigger but uses water not air to keep the intake air temp low so am not able to swap back and having tested both on the bench the Charge cooler is 100% more efficient. Now looking at the knock sensors. This is one item that would cause limp mode and no fault code. Replaced them last year but have had new parts fail before......just spent 1.5 hrs fitting a new encoder to a motor here at work yesterday and it lasted 3 hours 2nd new one still going strong. __________________ Coupe quattro 1986:-~450bhp + loooong list of mods! Audi A7 Bi-TDI SLine Black edition 2015 mapped to produce 600lb/ft torque! Audi S4 4.2 V8 cabriolet 2004:-

22-05-09, 06:10 PM	#35
20vcqdriver 4 ring whore! Classic Audi Club Member Join Date: Dec 2007 Location: Wirral Posts: 3,910	Sorted at last At last I can enjoy the homefry to the full after checking the knock sensors, one was loose. Tightened to 20nm and off down the road, let the engine oil warm up and booted it. Back is the quick spool up and gone is limp mode. What a difference a knock sensor makes. Just clocked a 2.5 sec 50-70mph in 3rd which is plenty quick enough for me.....at the moment. With any luck the 2.75" exhaust in July will get me a bit more over this 7A 2.25" system. Thanks to everyone for the help and advice. One to remember for the future. __________________ Coupe quattro 1986:-~450bhp + loooong list of mods! Audi A7 Bi-TDI SLine Black edition 2015 mapped to produce 600lb/ft torque! Audi S4 4.2 V8 cabriolet 2004:-

22-05-09, 07:56 PM	#37
20vcqdriver 4 ring whore! Classic Audi Club Member Join Date: Dec 2007 Location: Wirral Posts: 3,910	Also has a semi ported head and a chargecooler that even after my fast blast tonight was still cool on the outlet side, with this and the 2.75" exhaust and no cats these engines have been known to push out 297bhp. Once exhaust on I'll be off to a rolling road to see exactly what it is producing. Just removing the cats can get you 10 to 15bhp, my head work at worse is 5bhp and Paul Nugents 1.4bar chips with matching MAP sensor does the rest. Massive torque is more impressive with 60 to 80 in 5th in 4secs dead (I have the 6 speed gearbox) 1st pretty pointless unless I try towing a tank! As for fuel consumption well lets just say 'horrific' when the foot is down... Already sourced a new block that will be built with stronger rods and bearings to take the new turbos torque, ......once you start its hard to stop.. but I am not rushing it'll be 2+ years in the making... __________________ Coupe quattro 1986:-~450bhp + loooong list of mods! Audi A7 Bi-TDI SLine Black edition 2015 mapped to produce 600lb/ft torque! Audi S4 4.2 V8 cabriolet 2004:-

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
White odourless smoke!	Emjay	Electrical problems	27	21-01-11 12:40 PM
Black Sooty Smoke	Emjay	Engine	15	24-11-09 11:11 PM
Oil light issue	20vcqdriver	Technical Info	0	14-09-09 11:57 AM
Help 80 TDI Terrible Cold Start White Smoke	StompOn	Engine	3	16-08-09 05:59 PM
ETKA 7 Issue	Puglife	General Chat	0	22-02-09 09:59 PM

22-05-09, 10:32 AM	#33
Woodsman Grown up member Join Date: Apr 2009 Posts: 92	Sorry forgot to mention, rather than plugging in vagcom after a run. If you can drive the car with it connected while someone watches and saves the live data. You will be able to see what the ecu is seeing when it decides that it has seen a problem. watchng data while the engine is idling will confirm the sensors work, but you really want to be seeing the data in the split second before it goes limp. I'm not familliar with vagcom but on other diagnostic programs you can watch other ecu parameters as well as sensor readings eg; Measured airflow vs calculated airflow, is a good one for checking MAF Actual boost pressure vs boost requested and N75 duty cycle can be helpfull. Ignition angle + knock correction factor, some ecus will calculate this (and show you) seperatly for each cylinder, can be very helpfull. Hang in there, Can't be much left it can be Ps didn't mention the diagnostic conector, if its still in the fuse box you will need to relocate, extend etc

22-05-09, 07:33 PM	#36
Megsy Grown up member Classic Audi Club Member Join Date: Feb 2008 Location: cheshire Posts: 229	Glad to see its sorted Dave. Was wondering how you have got engine to 300bhp with just chips?

22-05-09, 08:02 PM	#38
Coxy 4 Ring Mafia Classic Audi Club Member Join Date: Jul 2007 Location: on the side of a hill in Shropshire! Posts: 28,215	glad to see it's sorted! Now you can change you're signature!

22-05-09, 08:25 PM	#39
Emjay Man Fettler Extraodinaire Classic Audi Club Member Join Date: Jul 2008 Location: Up my own arse blowing smoke Posts: 7,417	well done Dave, really pleased for you fella. I know how frustrating these things can be from personal experience. Now go enjoy for a while