N75 or Turbo Vanes

[dmjw01]

Basic Settings of Group 11 in VAG-COM.... Has anyone done this?

I had a go at doing this the other day. It takes the idle speed up to about 1400, and the glow-plug light flashes. Then you can see the MAP duty cycle going between 0% and 99.6% (why not 100?) at about 10 second intervals. If you listen very carefully you can hear a tiny whistle as the actuator is moving.

It was at this point that my laptop's battery died suddenly, leaving the engine stuck in this mode. Thankfully switching the engine off and restarting it brought it back to normal.

I reckon this might be a worthwhile bit of preventative maintenance for a few minutes every week or two - especially if you've been stuck in lots of traffic jams and haven't had the chance to give the engine some welly for a while.

 

[cheshire cat]

have you measured the vac ?

 

[muddyboots]

Maxcars -> Have you tried cycling the actuator as suggested ?

This sounds like a very useful maintenance routine, think I might do it over the Christmas break.

Actually I think I might have inadvertently done it once before, I was playing with vag-com and entered Basic Settings (can remember if it was block 11). Anyway I didn't know what I was doing, the engine revs started to rise, so I panicked and switched the ignition off and didn't try it again !

 

[maxcars1]

Muddy

I sat in with Mike at Jabba during the rolling road and he was in Block 11 dooing all the measurements. He said the car is doing everything it should be doing. I still think there's a mechanical issue here. I might get Mike to disconnect the actuator and ensure the lever that operates the vanes is defo free. I suppose the next step is strip and decoke, but I haven't got the funds at the moment for a hybrid.

Cheshire Cat

How do you measure the VAC? Again I assume that these were check against Vag Com whilst we were running the car on the RR - Mike had it sat on his knee whilst we were running.

 

[cheshire cat]

tap into the line it should give approx17"mg at tickover 2"mg at full throttle you could try leaving it at tickover then pump the brakes to see if the vac drops away any there may be a partial blockage somewhere non return valve and "T" on pump is favorite

 

[dmjw01]

Another test of the vacuum system, which I do from time to time in any car, is this: Before you start the engine, pump the brake pedal many times until it goes firm. It should go rock hard once the system has been purged. Then press your foot on the brake pedal while you start the engine - as soon as the engine fires, the pedal should sink down as the vacuum is restored.

 

[maxcars1]

Another test of the vacuum system, which I do from time to time in any car, is this: Before you start the engine, pump the brake pedal many times until it goes firm. It should go rock hard once the system has been purged. Then press your foot on the brake pedal while you start the engine - as soon as the engine fires, the pedal should sink down as the vacuum is restored.

Now that sounds like an easy check - will do that later today. Mike said try the brakes at over 2k revs and keep pumping them to see if they fade.

 

[cheshire cat]

Another test of the vacuum system, which I do from time to time in any car, is this: Before you start the engine, pump the brake pedal many times until it goes firm. It should go rock hard once the system has been purged. Then press your foot on the brake pedal while you start the engine - as soon as the engine fires, the pedal should sink down as the vacuum is restored.

it won't tell you what the control vac line is doing only pump and brake servo

 

[maxcars1]

it won't tell you what the control vac line is doing only pump and brake servo

What's the control vac line? Are these the various hoses that run from the N75 valve situated on the rhd strut top mount and run across the bulkhead?

 

[sssstew]

yep

 

[maxcars1]

Well I pop into Jabba today whilst I was on my way to look at a MK4 which had the ATD turbo I wanted. Had a chat with Brian and Nick, who mentioned about a problem they had in the past that was cured by the MAP Sensor. So the plan was to change this and the turbo would defo be the next step in the new year. So I pops down the breakers and there it is, an SX TDI with both headlights out and lots of room to get the MAP out. "That'll be £5 Sir" - drove home and the bloody car went into limp again 1hr later and scraped knuckles and its fitted. Take it out for a test drive and it pulls like a train. Take it to a notorious drag up hill on the A1 where I live and thrashed her in 5th at 110 plus - no hesitation or limp mode Still taking it back to Mike to put the map back on, but it's looking very hopefull.

 

[muddyboots]

Excellent news mate - fingers crossed it's fixed it.

Good stuff to know

 

[maxcars1]

Excellent news mate - fingers crossed it's fixed it.

Good stuff to know

Cheers Muddy

I was dreading the other option, but lets hope - I need the money for my other mods

 

[sssstew]

sounds like good news then. you sound about as releived as me when i fitted my new N18 and it solved my turbo boost problem some time ago.

im still wondering if logging the boost in vag com could have told you about the map sensor.....

 

[stoneyfordNI]

http://www.seatcupra.net/forums/showthread.php?t=74526&page=1&highlight=map

your other thread see post 17

 

[maxcars1]

http://www.seatcupra.net/forums/showthread.php?t=74526&page=1&highlight=map

your other thread see post 17

Didn't even think about it as I was in the hands of Jabba - it was just another avenue Nick said before condeming the turbo. I just felt I was going round and round in circles. Hopefully this has sorted it - it does feel a totally different car on the road now.

 

[maxcars1]

Something is clearly linked here as I went to pick up relatives for Xmas lunch and on the way back she went into limp There was a defo change in the car after I changed the MAP Sensor, with no limp and pulling like a train - something is linked here.

 

[stoneyfordNI]

wat u mean , so u changed the MAP sensor and all was well but now its in limp mode again

 

[maxcars1]

wat u mean , so u changed the MAP sensor and all was well but now its in limp mode again

Yep

 

[stoneyfordNI]

i take it alls well 4 a bit if u disconnect the battery and let the ecu resest , are all plugs safely on , ie the MAF n MAP sensors