G60 BTS and Idle

[Super-G 0]

I serviced my Corrado G60 the other day and found a few running issues.

 

When I unplugged the blue temperature sensor to check the timing, my idle increased rather than falling. I'm sure I've read somewhere that this means another sensor is out of range. The BTS reads 210 ohms at about 90 degrees and the Black sensor is about 110 ohms.

 

I set the timing to exactly 6 degrees then plugged the bts back in. The idle dropped, but only to 1000 rpm. When I plugged it into the black sensor the idle dropped to about 7-800 rpm.

 

I've checked a lot of the wiring around the engine bay and everything seems fine.

 

Injectors and wiring checked

ISV cleaned and wiring checked (I unplugged this whilst running, will I have damaged the ecu?)

Idle and WOT switches and wiring checked

Lambda Plug and Wiring checked

Hall sendor wiring checked

 

I'm now a little stumped what could be wrong.

Any help much appreciated.

 

Cheers,

Andy

[Supercharged 2]

It should drop slightly if timing etc is correct but engine needs to be warm (ie on normal map)

 

If the sender is more than 5 years old I'd change it anyway

[Super-G 0]

It's weird, because the revs do drop when it's unplugged when the cars cold, but when it's up to temperature and is unplugged the revs rise from about 1000 to 1150 rpm.

 

I'm sure I read that the increase means that another sensor is out. But which one could it be?

[waynos 0]

id like to know this too as i get the exact same thing, my idle also hunts up and down a bit

[ninoG60 0]

could it be your idle screw has wound its way out too much or the rubber seal has perished?

 

like has been said already, change the bts for a genuine vw one, i would

[Super-G 0]

The idle screw is actually wound all the way in and is threadlocked, so I don't think it'll be that. Will check the seal on it though.

 

What I'm confused about, is that the revs should drop when the blue temperature sensor is unplugged, not rise like mine do. I will try changing the BTS and see what that does. (Bugger, I only just replaced the coolant)

 

The engine pulls very smoothly throughout the rev range and the idle is as smooth as ever, just at 1000 rpm.

 

Are there any sensor that I've missed out?

 

Lambda Probe - 0.8 Volts Fluctuating

Black Temperature Sensor - 110 Ohms at 90 degrees

Blue Temperature Sensor - 210 Ohms at 90 degrees

Hall Sensor - Resistance correct at ecu loom

Knock Sensor - Replaced recently

Idle Switch - Tested at ecu loom

WOT Switch - Tested at ecu loom

ISV - Tested at ecu loom (Buzz's when ign on, also makes a clicking noise. Should it?)

CO Pot - Set at 550 Ohms

Air Temperature Sensor (Is there one and how can I test this?)

 

Cheers,

Andy

[ninoG60 0]

you shouldnt lose any coolant when changing the bts. keep us updated

[Super-G 0]

I haven't changed the bts as the cars been running ok. However, today when I started her, and things were not quite right.

 

After 30 seconds warming up, the engine note dropped considerably and struggled to idle. A bit of a play around and I found that disconecting the lambda made things run a lot better. I then measured the voltage of the lambda. When cold the signal wire from the lambda begins at 0.4Volts then gradually drops to 0.05Volts as the engine warms up. At this point the engine is struggling to idle, holding the WOT switch closed makes it struggle even more.

 

When the lambda fluctuates between 0 and 1 volts, is the higher the signal voltage telling the ecu to go richer or leaner?

 

I know something is wrong here, but I'm wondering if it's the probe or the wiring.

 

I am getting 13 volts to the heater wire, (I guess this is the power for the lambda probe?)

 

Could something else be causing the car to overfuel and the lambda is just telling the ecu to go lean? Or should the lambda signal still fluctuate?

 

Any help appreciated :confused4:

[Super-G 0]

Ok. I think i've found out that 1 volt signal from the lambda is telling the ecu to go rich and the the lower the number it's telling it to go lean. Is this right?

 

So is my lambda just telling the ecu to go lean or is my lambda caput and the voltage should still be cycling up and down?

[Super-G 0]

After playing around with the lambda plug I managed to get a fluctuating voltage signal from it. So for now that's working fine, but something else is wrong now. With everything plugged in, the idle is all over the place and the engine coughs when being driven with very gentle throttle. Unplug the ISV and it's fine. It's been cleaned out, but it wasn't that dirty as was replaced in 2005 with a new unit. I've now found in the SH that the bts was repalced in 2006 with an original VAG item, and I'm pretty sure that's reading correctly.

 

I have noticed the ISV runs off the ECU relay, could this be causing the fault?

 

When the cars running at idle there is a 12volt (slightly fluctating to 10 Volts) supply to the ISV plug. But it really dosen't like running with it plugged in. Does 12 Volts to the ISV fully open it or close it?

 

The car runs fine with the ISV unplugged, but is this putting the ecu into limp mode?

 

Obviously I'll be losing some boost through it with it unplugged, but I can't seem to get the car to run properly with the ISV removed altogether and the breather blocked off. Is this possible and how?

[Super-G 0]

At last, I think I've sorted it :cheers:

 

About a year ago, I replaced my crankshaft pulley bolt with a DX item, as I was unsure of the age of the stretch bolt in there. I did this without removing or moving the crankshaft pulley (something I wish I'd done now) and just carefully swapping the bolts over. Last week I noticed my flywheel TDC mark didn't line up with my lower timing mark on the supercharger pulley. I thought this was a bit weird and after doing some reseach, decided to removed the crankshaft pulley. Quite glad I did really, the key was totally battered on one side. The end of the crankshaft was also showing signs of where the pulley had once been loose and wobbled on the crankshaft. The keyway on the crankshaft had survived unscathed, so after refacing the crankshaft a new pulley, sourced from VW, was bolted on. I then replaced the timing belt and tension (even though they'd only done 10k :cuckoo: ), set the timing and idle up which is now rock solid at 850rpm.

 

Here's the key on the old pulley!

 

 

Thought all was sorted, but then all of a sudden the engine cuts out. Go to restart it and the fuel pump doesn't prime. :censored:

 

Wiggled the ECU relay and it primed. Strange. Having looked through my SH I've noticed that for some reason the fusebox was replaced in 2005 and then the ecu relay was replaced with a VW item in 2006. After dropping the fuse box down and not finding anything too untoward, I took the relay apart and inspected it with a magnifine glass. I found one dry solder joint and the main power pin (30) had completely broken free of it's solder and was loose in the board. After resoldering this, all is happy again :clap:

 

However, from behind my fusebox I have found two wires. Could anybody shed any light on them :help:

 

This Yellow plug above the fusebox

 

And this green plug from behind the fusebox

 

Should they be plugged into anything, or are they there for testing somthing?

 

Cheers, Andy