Gti-6 Emission Problems!

[Tom_Gallington06 9 1 Cars]

Hi, just wondering if anyone could help me. My car went for it MOT after i had done the gti-6 conversion and failed on high CO. It is reading around 5. The co2 is low and the hydrocarbons are pretty low to. It has a new lamda sensor so it shouldnt be that. Except when i went to check the lamda plug that it connect to, pins 1 and 2 that should have been reading battery voltage as reading about 0.4 volts. So i assume it isnt heating it up. But i dont no why the ecu isnt sending 12v to it. Or weather it is another fault in the system as i dont have the plug to plug it in for diagnostics.

 

So i was just wondering if anyone else has had the same problem as me and has been able to sort it out?

 

Cheers Tom

[welshpug 1,657]

ecu doesn't heat the Lambda up, its on a separate fused supply with ignition.

[Alastairh 47]

Yeah, when you or someone else did the loom, did they give the heater 12v switched feed?

 

Al

[Tom_Gallington06 9 1 Cars]

Yeah, i put a switched live from pin 14 to one of the heater wire, but should i put it to both of them??

[welshpug 1,657]

check that you are getting earth then

[Tom_Gallington06 9 1 Cars]

So is pin 2 on the lamda plug spose to be an earth? And pin 1 battery voltage? As i thought thats what it was spose to have, but when i connected across the terminals i was only getting about 8 volts. when i was spose to be getting battery voltage (11.5-12v). When it was like this i got it on the emissions machine and the co was running at about 4.9.

[Mad Professor 7]

I don't know the GTi-6 Setup very well, is your O2 Sensor, 2x2Pin Plug or 1x4Pin Plug?

 

If it's the 2 plug design I know that plug A is for the signal, and plug B is for the power.

 

PlugA Pin1 - Wire 131 - ECU Pin 28.

PlugA Pin2 - Wire 130 - ECU Pin 10.

 

PlugB Pin1 - Ground.

PlugB Pin2 - Switched Feed.

 

I don't know if this is of any help.

Edited February 1, 2009 by Mad Professor

[welshpug 1,657]

gti6 runs one 4 pin AMP plug,

 

pin 1 white, pin 2 white pin 3 grey pin 4 black.

 

pin 1 is feed,

pin 2 earth,

pin 3 to wire 130

pin 4 to wire 131

[Tom_Gallington06 9 1 Cars]

Ok, cheers, i will have a look. And get back to you. As the engine has been tuned slightly and has been cammed (unknown spec) This shouldnt bring the emissions up to high should they??

 

Cheers again.

[welshpug 1,657]

depends what has been done, most cams that will fit in a standard engine aren't wild enough to cause major issues.

 

 

just a wild guess, but does it have an FSE boost valve?

 

if not, check the vacuum pipe from the fuel pressure regulator to the manifold, if it does, bin it...

Edited February 1, 2009 by welshpug

[Tom_Gallington06 9 1 Cars]

It has a standard fuel reg, with the vacuum pipe fitted. So what diffrence will it make if i bin that??

[welshpug 1,657]

I wasn't saying bin that!

[Tom_Gallington06 9 1 Cars]

Ow, the fse boost. Ok well i will have to check my wires next saturday as im away at work all week and get back to you. So just to get this straight, you need to connect a switched live from the pin 14 to pin 1 on the lamda? Sorry im just abit annoyed with it. And am i right sayin that pin one is a red wire(loom side) on the plug, pin 2 is green, pin 3 is yellow and green and pin 4 is grey?

[leon 1.9 0]

GTi6 wiring diagrams are here.

http://forum.205gtidrivers.com/index.php?showtopic=99663

 

I think what welshpug was saying is that you need to check that pin 2 of the lambda is earthed too. Just use a meter and check resistance of pin 2 vs a known earth point (any unpainted chassis bit or the battery neg). There should be very little/ no resistance between the two (meter should read ~0 ohms, definitely not read Open Circuit.)

 

Then check pin 1 has a switched 12V feed. From what I can see the double relay gives 12v through its pin 5, through the inertia switch ( cuts fuel in an accident) and to the lambda and fuel pump.

 

Whoever wired the car in should have either kept the inertia switch and the wiring to fuel pump AND lambda, or taken out the switch (which is often done) and wired in the pump and lambda directly. They should split off somewhere between the double relay wiring and the fusebox where the fuse for the fuel pump is I guess.

 

I'm not an expert but hopefully this might help.

 

You will need the ignition on (but not the engine running) to switch the relay and get power to the lambda though.

[Tom_Gallington06 9 1 Cars]

Cheers mate, will try on the weekend. Thanks for the link to the wiring diagram, Its going to help alot.

 

Cheers Tom

[CaptainK 11]

Ok, cheers, i will have a look. And get back to you. As the engine has been tuned slightly and has been cammed (unknown spec) This shouldnt bring the emissions up to high should they??

I had the exact same problem as you. I have a cammed GTi6 and it failed on emissions at 6 odd CO I think. Everything else was fine. Also had a new lambda in there. BUT, upon closer inspection we found that the loom to the lambda probe was incomplete by the person who did my installation. Basically the lambda heater wires weren't connected up, so it wasn't getting heated. Thus lambda not working properly and feeding the ECU the wrong signal causing it to overfuel and thus emissions to go sky high.

[BuD 0]

I too had a very similar problem: http://forum.205gtidrivers.com/index.php?s...ic=95770&hl

 

Coolant temp sensor and lambda are the 2 most obvious things with high emmisions, dont expect it to light the ecu light - its a peugeot

 

Good info on testing gti6 sensors: http://www.306gti6.com/forum/showthread.ph...0340&page=1