G60 running rich and cutting out

[rs200f40 0]

Hi,

Hope someone can help me with this problem that's just occured. Happened fairly suddenly, pulled away from one roundabout and it was fine but exiting the next one the engine refused to accelerate when I pushed the accelerator.

 

Symptoms are,

Idle has dropped to about 700rpm

Running rough from 2000rpm, feels a bit like on 3 cylinders.

All Plugs are very black and exhaust is smoking (running very rich)

Using half throttle the car will accelerate slowly but pushing it to the floor feels like it's hitting a rev limiter.

 

I've changed the black water temp sensor as I had a new one lying around but it made no difference.

 

Does anyone have any ideas what to look at or try/test next?

Nothing obvious seems out of place or broken.

 

Thanks

Alan.

[Jim 2]

If the smoke coming from the back of the car is quite thick and black, this could be related to your lambda probe.. very similar symptoms to other occasions when I have heard of the lambda going. And it can just come on like that as well.. working fine one minute then playing up!

[rs200f40 0]

Hi,

Do you know where the lambda probe is and how to get to it on a G60? Just had a look under the car and round the back of the engine the best I could and can't find it, can't even see any wires that might be leading to it.

 

Thanks

Alan.

[rs200f40 0]

Had a look at ETKA to try and find the lambda sensor and the only picture I can find shows it in the back of the exhaust manifold. Had another look at the car and felt all around the manifold and downpipes to the joint with the rest of the system and I can't find a lambda sensor or wires anywhere.

Do 1991 G60's have a lambda sensor?

 

Thanks

Alan.

[h100vw 0]

Alan, it's the blue plug that feeds the ECU temp.

The lambda probe should be visible by looking down the back back of the engine on the drivers side. The plug is a 4 wire one, the wires are usually very delicate due to the heat in that area.

To eliminate the lambda probe, you could try taping up the Wide open throttle switch on the throttle body. With this switch taped up, the ECU will ignore the probe and run purely from saved maps.

Have a look on http://www.snstuning.com in the DIY section for other pointers.

 

Gavin

[Henny 0]

I'd also change the Blue temp sensor... they're around £7 from Euro or GSF... The black one you've already changed just does the temp gauge on the dash...

 

A good quick test is to swap the blue and black plugs over, if your water temp gauge then stops working properly and the car starts running OK, then this shows that teh blue sensor is definately dead...

 

It's also worth checking the vacuum hoses which come off the back of the throttle body... if one of those has come loose or become damaged, then the ECU won't know what the hell is going on and your car will run like a dog... :|

[rs200f40 0]

Thanks for the tips everyone, had a look at the SNS site and followed some of there tips. Adjusted the air temp sensor as it was well out (371 ohms, should be 500 ohms) but didn't make any difference. Unplugged blue sensor and engine ran worse so assume it's ok, taped up full throttle switch and car ran worse at lower revs. Unplugged the lambda probe and it made no difference so it looks like it's definately dead.

Does anyone know if there is a generic lambda sensor that can be used and crimped to the VW connector, I hate to think what VW will charge for one. Would any 4 wire lambda sensor work?

 

H100VW, whould I be safer to tape the switch up permanently until I get the car to a garage to get the lambda sensor changed. It's won't run well at lower revs but will it prevent the car running so rich at 2000rpm+?

 

Thanks

Alan.

[Henny 0]

both Eurocarparts and GSF do the universal Lambda which will fit the Corrado...

 

The Lambda itself live just behind the engine bay on top of either the front of the cat or the cat-bypass pipe... 8)

[h100vw 0]

You can get 'universal' probes. I cannot comment on how well they work having never needed one. Touch wood :mrgreen:

 

If I were to replace mine I would consider missing out the factory connector if possible as that is a potential scource of problems.

 

Setting the pot to 500 Ohms is for folk who have no access to a gas tester. It is just a safe value to use. No substitute for a proper setting up.

 

I think if taping up the switch made no difference then you have something else wrong. Not the probe.

 

I would look at vacuum pipes. The 2 on the TB and also the short piece that goes to the FPR on the drivers side of the inlet manifold. Has your tickover screw would itself out??

 

The pipe from the TB to teh ECU should be exactly 1 Metre long make sure that has not been shortened sometime. Cutting 2 cm off doesn't make a noticeable difference but 5 or more does, in my experience. Also check that the battery voltage when the engine is running is high enough. If it drops close to 12-13 then the ECU starts overfuelling as a safety measure.

 

This scenario can also be caused by a engine bad earth. There should be one from the TB to the coil bracket.

 

 

Hope one of the above nails it for you.

 

gavin

[scruffydubbers 0]

had exactly the same problem with mine, from what you describe.

 

i changed the blue temp sensor and the lambda sensor and it works fine now. altho this might not be the case for you.

on mine when you unplugged the lamda sensor it ran ok.

 

i was going to buy a universal lambda sensor from gs+f but they told me they had some running probs with them so i got one from vag which cost around £85 :x

 

heres the part number on mine 037 906 265 B

[rs200f40 0]

Thanks All, all sorted now.

Turned out to be the vacuum hose from the throttle body to the ECU that had half broken off behind the throttle body.

 

Thanks

Alan.

[h100vw 0]

sweet :mrgreen:

[Henny 0]

YAY! Glad that you got it sorted... 8)

[Andy T 0]

 

i was going to buy a universal lambda sensor from gs+f but they told me they had some running probs with them so i got one from vag which cost around £85 :x

 

heres the part number on mine 037 906 265 B

 

you probably done the best thing, a few mates of mine (not vw owners) have had lambda probes replaced my garages at £80-100 + labour, and they have only lasted 10-15k miles!

 

I think the cheap ones are made out of inferior metal, probably not cost effective in the long run!