Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[richard]

Afternoon

2.2 cd lpg auto  110k  LPG  2003

MOT failed on emissions readings as below

Fast Idle
             CO   (.3max)     reading .8   fail
              HC    (200max)  reading 31   pass
LAMBDA         (1.030max) reading .97 pass

 2nd fast idle
              CO   (.3max)     reading .285   pass
              HC    (200max)  reading   9   pass
LAMBDA         (1.030max) reading .99   pass

Natural Idle

           CO     (0.5 max)   reading 4.47   fail



Garage tested on LPG are the max levels the same as petrol they seemed unsure.

I have since cleaned breather properly and they are now clear.  Will this make a differance.

Emmissions light was on   its now gone off.

Daz is coming at the weekend to do Cambelt but wanna get MOT sorted B4 if poss 

Any ideas 

PS  Kev had a tech 2 read and all seemed ok

[Kevin Wood]

Hi Richard,

Is it still running rough on petrol but OK on LPG?

I couldn't find anything wrong when we Tech 2'd it but there were some odd things going on which suggests a fault.

Something odd is (still) going on there. Firstly, yes, I believe if it is presented on LPG then looser limits apply but that has failed the natural idle test by such a margin that I don't think it will help.

4.47% CO suggests it's running very rich however the Lambda readings look Ok for the fast idle tests.

I wonder if it's worth getting it retested on petrol?

IIRC I took a datalog on each fuel and the Lambda sensors were reporting a solid Rich on LPG and Lean on petrol.

I think perhaps the LPG system is overfuelling, either due to leaky injectors (petrol or LPG) or poor calibration. This is having a knock on effect on petrol because the fuel trims are getting wound down too low.

In would say drive it on petrol only and forget LPG for a while and see if it improves. Once it's running OK on petrol get it retested and see what's what. If it recovers and tests Ok we can consider the LPG setup. If not, then we can look elsewhere. :-/

Kevin

[megaomega123]

I got mine tested on petrol as opposed to lpg. I always put some redex in before MOT too, seems to do the trick.
Also, my lpg overfuelling was down to one loose spark plug which ended up goosing the injector to that cylinder.

[mark.adams]

I had exactly this scenario a couple of months back, the MAF was shot but not causing errors with eml, it was causing overfuelling, which killed the cat and gave high emissions figues for the MOT. S/H cat and new MAF fitted, now works perfectly.

[Kevin Wood]

MAF looked ok on the live data when I had a look, but MAF problems can often be subtle.  :-/

Kevin

[richard]

Thanks gents for all the advice !!!!!

Ran it on Petrol (optimax) with loads of Redex for a few days.
Kept the LPG off.
Cleaned my breathers and it passed with flying colours.
Thanks again to all.

Roll on the new cambelt friday (daz )

[mark.adams]

MAF looked ok on the live data when I had a look, but MAF problems can often be subtle.  :-/

Kevin

Kev, so did mine i only replaced it out of frustration. I still firmly believe it was the overfuelling that killed the cat....

[Kevin Wood]

MAF looked ok on the live data when I had a look, but MAF problems can often be subtle.  :-/

Kevin

Kev, so did mine i only replaced it out of frustration. I still firmly believe it was the overfuelling that killed the cat....

Yep. that was the point I was making. It doesn't have to be far out to cause a large mixture error and, at a glance, the readings still look to be behaving normally.

Kevin