Author Topic: Co pot  (Read 6240 times)

Offline delirical

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Co pot
« on: 07 October 2010, 13:46 »
Hi,

My mk2 g60 is bugging me.

I think the co pot is faulty as it only reads up to 170 ohms and wont go higher, time to replace?

I have checked the vacuum hoses, changed the dizzy and arm, new plugs, cleaned out the ISV but it is still not running properly.

When getting warm it starts hunting and cant hold idle, it wants to die and trys to misfire.

Please help!

Offline tommy Dee

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Re: Co pot
« Reply #1 on: 07 October 2010, 18:29 »
please help him!

ive been playing with it all week and starting to dislike the g60 engine  :embarassed:  :embarassed:

Offline clipperjay

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Re: Co pot
« Reply #2 on: 07 October 2010, 18:34 »
cleaning the ISV is like cleaning a broken turd its still a broken turd but clean?

Co pot you can adjust it by the way :wink:

Offline delirical

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Re: Co pot
« Reply #3 on: 07 October 2010, 20:07 »
ahh ok, how can you adjust it? it works as you can feel it buzzing with the ignition on.

Im really stuck mate, the g60 doesnt have a lambda plugged in either so this could be part of the issue?

Offline delirical

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Re: Co pot
« Reply #4 on: 07 October 2010, 20:27 »
I need to buy a lambda and wiring for the g60 would this do the trick?

http://www.lambdasensor.com/main/bosch/price.pl?item=0258003973

Offline clipperjay

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Re: Co pot
« Reply #5 on: 07 October 2010, 20:47 »
Jeez you know nothing about the digi G60  :laugh:
Its ok I didn't either five years ago :grin:

Ok the co pot has a white cap need to peel that back it has a flat head screw adjust according to ohms.

Ok you mean the ISV buzzing right? Well it can buzz as much as it likes if the valve doesn't open and close properly it Fooked.
I would clamp all the pipes off it and see if it makes a difference in idle!
Or unplug it when hot the revs should drop a tad. Let me know what happened?

Lambda ok now your giving me some good info!
The ECU can default one signal ONLY so if your Co pot is fooked and you have a missing Lambda signal the ECU will default only one value and that poor G60 will run like poo!
So you need to check on the downpipe if you have a Lambda already there or at least a boss nut where it should be? The plug can be wired right behind the water expansion tank its there just look and trace a missing plug or the existing wire to the down pipes orignal Lambda!
I would only buy Bosch one as I have gone through two after market ones and the quality is just poo!
 Lambda on a g60 will be either three pin or two pin but if you have two pin don't worry you can bridge two white cables togther its the ground some run three wire but an extra white wire can be mated!

Hope that helps you need to read up certain articles I'll upload some stuff for you to read the files are too big for email.

Your welcome  :nerd:
Jay

 

Offline tommy Dee

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Re: Co pot
« Reply #6 on: 08 October 2010, 17:40 »
Jeez you know nothing about the digi G60  :laugh:
Its ok I didn't either five years ago :grin:

Ok the co pot has a white cap need to peel that back it has a flat head screw adjust according to ohms.

Ok you mean the ISV buzzing right? Well it can buzz as much as it likes if the valve doesn't open and close properly it Fooked.
I would clamp all the pipes off it and see if it makes a difference in idle!
Or unplug it when hot the revs should drop a tad. Let me know what happened?

Lambda ok now your giving me some good info!
The ECU can default one signal ONLY so if your Co pot is fooked and you have a missing Lambda signal the ECU will default only one value and that poor G60 will run like poo!
So you need to check on the downpipe if you have a Lambda already there or at least a boss nut where it should be? The plug can be wired right behind the water expansion tank its there just look and trace a missing plug or the existing wire to the down pipes orignal Lambda!
I would only buy Bosch one as I have gone through two after market ones and the quality is just poo!
 Lambda on a g60 will be either three pin or two pin but if you have two pin don't worry you can bridge two white cables togther its the ground some run three wire but an extra white wire can be mated!

Hope that helps you need to read up certain articles I'll upload some stuff for you to read the files are too big for email.

Your welcome  :nerd:
Jay

 




Thanks for helping mate! I've tried adjusting the co pot and it goes from 0-180 ish.... I assume this is faulty then?! Is it stealers only for this?? I'm sure I'll be called down to look for a lambda hole now..... Will it be under car or between engine and bulk head?

If there is no hole for it..... What do you suggest the best way of getting it in there? Drill a hole n thread it? Or get a new down pipe with correct hole?


On behalf of delirical.... Thanks alot!!
Your a handy guy to know lol

Offline clipperjay

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Re: Co pot
« Reply #7 on: 08 October 2010, 18:34 »
Right first things first  Did you test pin 1 & 3, if you did and got 180 ohms and when you adjusted the Co pot screw values didn't change the resistance then I would say yeah its gone! The reading should have been about 500-600 Ohms on the meter!

You did check the temperature sender aswell right? Blue one should have read 180-230 ohms anything over 260 it needs replacing.
When its upto temperature pull the blue plug and see if the revs drop a bit this will let you know the ECU has gone into service mode. If it didn't it was proberly already in service mode  :grin:

Your down pipes should branch off to two pipes the lambda would be located just on that junction. You can't miss it it would have a thick cable leading to the lambda.
I would be very worried if there was not at least the broken lambda still stuck in the pipe!
If you can't find one then someone has been playing silly buggers and change the down pipes and forgot a Lambda should be there :laugh:

The only way I know is to drill a hole and weld up a boss nut that has the same thread head as a lambda.
It should be universal fit, can't remember pitch sizes or nut size TBH.
By the way have fun gettting the old lambda off its still there!

Did you check the Vac pipe from the ECU? It should be tight and EXACTLY 1 meter long to the bay!
 
Other sensors to check whilst down there!
Knock sensor check cable for cracks and brittleness due to block heat
Throttle switches make sure they click!

Good luck you have a bit of work to do mate! :smiley:
Jay

Offline Dolly

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Re: Co pot
« Reply #8 on: 08 October 2010, 19:55 »
The Co pot was set around 6 months ago according to the figures suggested off Dub force.

The car has a 4 branch manifold so no lambda fitted, there is a small section of removal pipe between manifold and the rest of the system, remove this drill it on the side, well a nut on and screw a sensor in. i though the oxygen sensor wiring was the 4 pin connector tucked behind the airbox with the lengthy wiring on the back of it. you can get 4 pin lambda sensors ( seen them listed )

but if the above claim of either 2 or 3 pin connectors is correct i have no idea. ( there is an unused 3 pin connector near Co pot. )

Offline clipperjay

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Re: Co pot
« Reply #9 on: 08 October 2010, 20:15 »
So Dolly this was your old G60 conversion?
I remember when  you set about doing this!
 
So that said if the Lambda was in service mode it would have not defaulted to a generic map for the Co pot if that was down aswell.
The lambda plug on the Rallye was always tucked behind the expansion tank not sure if it got rerouted near to the Co pot?

If it has a 4 branch manifold then it must drink without the Lambda pluged to sort idle.
Do you have any pictures of the old lambda so they can see where and what angle it was located?
If not then its should be at the side of the pipe, never straight up or on top where you can never get it to fit anyway due to tunnel. Or the best angle is on the side with cable sticking up at a 45degree angle.
The reasons why you want it at the end of the branch is because you want the sensor of all branches into one blowing exit pipe to give the best results.
Failing that, Fix all of it except the Lambda and have it default that ONE sensor, but it will drink fuel without it, as its a rich default map to save it leaning out!