Running rich and no idle when hot

[Lighthouse]

Hello!
First of all, sorry for the poor english
I have a problem with my 3B that i dont understand and could need a litle help from you experts in here
When the car gets hot ( 90 C ) it wont idle and dies. Sometimes i help it with the throttle to get it running on idle. I read on SJM Autotechnik that the G62 sensor would have this behavior so i measured it. It was in the spec, 1500-3000ohm depending on temperature. I did not change this, but I changed the MTS sensor ( multi malfunction as some of may call it)i had one extra but still no luck.

Checked for vacum leaks but cant find any( that wouldn't made it go rich would it?) Changed the MAF,ISV.

What can it be? Can anyone help me?

[90/90qs]

Is the G62 the coolant temp sensor in the head? If not that would be my first guess.

[UrS4boy]

Is the G62 the coolant temp sensor in the head? If not that would be my first guess.

Link to G62 and MFTS info:

http://forums.audiworld.com/showthread.php?p=18871694

[Lighthouse]

Is the G62 the coolant temp sensor in the head? If not that would be my first guess.

..sensor in the head? Not sure what you mean, but the G62 sits in the back of the engine close to the torpedo wall. I measured this sensor as I said in the post above here, and the spec said that it was going to be from 1500-3000ohm depending on the temp, but I got on now and will try to fix it see.

[Lighthouse]

Link to G62 and MFTS info:

http://forums.audiworld.com/showthread.php?p=18871694

Thank you!

[Lighthouse]

Still no luck!

Tried to change the G62, but still no better
I see that there is one more sensor besides the MTFS. Can anyone tell me what this does? Changed both the MTFS and G62 now.

Help!

[90/90qs]

I'd look at the fuel pressure regulator next

[Lighthouse]

I'd look at the fuel pressure regulator next

..and what would you look after there?
I think i read something about a "membrane" thingy that could crack up, is this correct?

[europeanme]

..and what would you look after there?
I think i read something about a "membrane" thingy that could crack up, is this correct?

http://www.s2forum.com/forum/showthread.php?t=38658

Any of these symptoms ring any bells??....then it could be the FPR...but if you do find yourself changing it, wear something over your face or stand to one side when it blows, coz it will and with quite a bit of force...

good luck....

[90/90qs]

pull codes (determine if it's O2 sensors or other), then look at possibly leaky fuel injectors.

[Lighthouse]

pull codes (determine if it's O2 sensors or other), then look at possibly leaky fuel injectors.

pull codes? Can you enlighten me on that, please?

Europeanme: Thanx, will keep that in mind.

I think this fault i very strange, or I just dont get it ( propably the last option)
When the car is cold, it runs on idle, but after it reached 90 Celsius it stops. I checked the rubber seal around the throttle damper, the rubber"spring" that slows down the throttle. Not easy to explain this in english when I dont know what it's called.
As I read there is one more blue sensor that sits on the rubber hose, is this correct? How does this work? Tempting to just change all, but at the same time a big waste if doesn't help..

[Lighthouse]

http://www.s2forum.com/forum/showthread.php?t=38658
Any of these symptoms ring any bells??....then it could be the FPR...but if you do find yourself changing it, wear something over your face or stand to one side when it blows, coz it will and with quite a bit of force...

good luck....

Read your thread now,and I must say that I dont experience the same as you did
Works like it should, but is running rich and will not idle when its hot. Checked/replaced all the hoses that even looked a little bad.

[90/90qs]

This is not for the ABY, and is for U.S. cars, but maybe it similar on that vehicle?

http://www.20v.org/engprob.htm#faultcodes

(anyone correct me if I'm wrong here)
When you start your car cold it runs "open loop" because the O2 sensor does not sense properly until it's hot. It dumps a baseline amount of fuel into the system until the sensor is capable of metering correctly. Then the ECU takes over the fueling, and adjusts according to the O2 sensors output. If the sensor(s) fail, the car will stay in open loop operation. It's a kinda like an auto choke I guess.
You are probably:
a) running too rich because of the FPR or some other vacuum leak (presuming you haven't already eliminated it as a possibility). - as a note, I've heard of leaky valve cover gaskets causing similar problems as well, but not on this car.
b) running too rich because the fueling system is not metering / supplying properly. -This could mean O2 sensors failing, fuel pressure regulation, intake obstruction or dirty air filter (not likely, but may contribute)

[Lighthouse]

This is not for the ABY, and is for U.S. cars, but maybe it similar on that vehicle?

http://www.20v.org/engprob.htm#faultcodes

(anyone correct me if I'm wrong here)
When you start your car cold it runs "open loop" because the O2 sensor does not sense properly until it's hot. It dumps a baseline amount of fuel into the system until the sensor is capable of metering correctly. Then the ECU takes over the fueling, and adjusts according to the O2 sensors output. If the sensor(s) fail, the car will stay in open loop operation. It's a kinda like an auto choke I guess.
You are probably:
a) running too rich because of the FPR or some other vacuum leak (presuming you haven't already eliminated it as a possibility). - as a note, I've heard of leaky valve cover gaskets causing similar problems as well, but not on this car.
b) running too rich because the fueling system is not metering / supplying properly. -This could mean O2 sensors failing, fuel pressure regulation, intake obstruction or dirty air filter (not likely, but may contribute)

I have a 3B engine, lots of things to learn and read here! Thank you!
Checked vacuum leaks and cannot find anything. Airfilter is new, so I will check out the FPR tomorrow. Is it any way to check the 02 sensor?

[Lighthouse]

The more I read about it (SJM Autotechnik) I start to wonder if it could be the lambda the ******* up my car. The lambda isn't that old either so im confused!