Mot emissions failure
Discussion
450 failed by some way the CO and HC test today,
The tester said average required v actual were;
CO 0.3 v 8.6
HC 200 v 2640
Lambda 0.9 to 1.1 v 1.6
As mentioned earlier a new stealth cam is in and due for a remap/rr test next week with jools but wondering if its worth holding back until I've fixed this.
Tester thinks its ecu fuel management mix "and i used to build rally cars"
I've had the car 2 years and I'm curious to know if the main cat is in (update: it pushed some bike brake sheath in there and stops at the cat area)! I know exhaust cats are in. Last year the tester was more sympathetic of tvrs.
Fwiw- new sparks are in
So could the ecu or lambda's be misbehaving?
The tester said average required v actual were;
CO 0.3 v 8.6
HC 200 v 2640
Lambda 0.9 to 1.1 v 1.6
As mentioned earlier a new stealth cam is in and due for a remap/rr test next week with jools but wondering if its worth holding back until I've fixed this.
Tester thinks its ecu fuel management mix "and i used to build rally cars"
I've had the car 2 years and I'm curious to know if the main cat is in (update: it pushed some bike brake sheath in there and stops at the cat area)! I know exhaust cats are in. Last year the tester was more sympathetic of tvrs.
Fwiw- new sparks are in
So could the ecu or lambda's be misbehaving?
Edited by Chimp871 on Saturday 23 July 12:17
meanwhile..... plugged in rovergauge to check if there's any faults.
The lambda odd is fluctuating around zero to -70 but the lambda even is a constant -100%.
Here's the RG data link and pic below.
https://www.dropbox.com/s/bzte6fs1scfkhdf/2016-07-...
The lambda odd is fluctuating around zero to -70 but the lambda even is a constant -100%.
Here's the RG data link and pic below.
https://www.dropbox.com/s/bzte6fs1scfkhdf/2016-07-...
interesting. Engine has been rebuilt so senors should drop out easily enough. So in theory the issue could be:
Dodgy lambda sensor (but RG shows it does ramp up from 0 to 256)
Misfire - help explain the high HC. FWIW - all plugs are new so possibly injector problem, injector wiring, spark wire (magnatec but don't know age) or extender.
Anything else to add?
Jools has been helping me out saying a high lambda reading of 1.6 doesn't make sense as this is a lean setting not rich. And pointed towards misfire or sensor.
I'll read the even bank sensor tomorrow and then swap it over.
Dodgy lambda sensor (but RG shows it does ramp up from 0 to 256)
Misfire - help explain the high HC. FWIW - all plugs are new so possibly injector problem, injector wiring, spark wire (magnatec but don't know age) or extender.
Anything else to add?
Jools has been helping me out saying a high lambda reading of 1.6 doesn't make sense as this is a lean setting not rich. And pointed towards misfire or sensor.
I'll read the even bank sensor tomorrow and then swap it over.
update: so removed the both lambda sensors and swapped them over.
End result is they both now trim, hopefully as they should. When I removed the O/S sensor the red/white/black wires on the sensor side were not matched up with the red/white/black wires on the ecu side. I assume this is why the sensor readings were weird.
Took the advice of going for a long run and logged it with roverguage (see link below), from line 100 you'll see the sensor trimming on both sides at speed but have no idea if it's as expected. But I'll the rule out a faulty lambda sensor for now, but still would appreciate your feedback on whether the MOT HC fail would be caused by a non-working lambda sensor (due to incorrect wiring)?
Qbee many thanks for the offer for putting in a y piece. I've the standard one. I'll see what jools says and go from there. BTW - can he do MOT tests?
PS - on RG really weird is only shows road speed at around 33mph when I defo was moving faster.
https://www.dropbox.com/s/uvdmp3z56sogmti/2016-07-...
End result is they both now trim, hopefully as they should. When I removed the O/S sensor the red/white/black wires on the sensor side were not matched up with the red/white/black wires on the ecu side. I assume this is why the sensor readings were weird.
Took the advice of going for a long run and logged it with roverguage (see link below), from line 100 you'll see the sensor trimming on both sides at speed but have no idea if it's as expected. But I'll the rule out a faulty lambda sensor for now, but still would appreciate your feedback on whether the MOT HC fail would be caused by a non-working lambda sensor (due to incorrect wiring)?
Qbee many thanks for the offer for putting in a y piece. I've the standard one. I'll see what jools says and go from there. BTW - can he do MOT tests?
PS - on RG really weird is only shows road speed at around 33mph when I defo was moving faster.
https://www.dropbox.com/s/uvdmp3z56sogmti/2016-07-...
Edited by Chimp871 on Sunday 24th July 22:02
Cheers gents.
Its got new sparks and was warmed up appropriately before arriving. If that's the italian prep?
I've booked her in with an indy LR garage for Monday. From speaking to them they seemed to 'get' tvr's rather than the regular garage down the road.
Fwiw- The test print said the parameters were for all chimaera's and griffiths 400 through 500. Just to confuse it more the test engine size said 4200 cc
Its got new sparks and was warmed up appropriately before arriving. If that's the italian prep?
I've booked her in with an indy LR garage for Monday. From speaking to them they seemed to 'get' tvr's rather than the regular garage down the road.
Fwiw- The test print said the parameters were for all chimaera's and griffiths 400 through 500. Just to confuse it more the test engine size said 4200 cc
Failed at garage number 2, turns out the local indy 4x4 place farms out their mot work.
Threw in some cataclean to a 1/4 tank last night for a 20 mile drive followed by a 20 mile warm up drive today.
Natural idle test passed but both fast idle tests had a fail: test 1 had too high CO and test had too high CO and HC (why would a higher HC have a lower CO?)
On my theory list of possible causes are:
Test MAF
Change air filter
Change extenders/leads
Clean injectors (as in send off)
Coil pack (?) not sure on this one but maybe a misfire even though brain says misfire would have far higher HC content.
Trying my hardest not to the C word as this is proper money and a worst case, 3 cat's! s
t went and said it. May switch back OE chip for next test
Sparks were already new
Just plugged RG in and its saying map 5. Limp home mode from the experience i had stops any power over 2000 rpm.
MAF at idle is 33% at direct setting on RG which I believe from Blitz's g33.co.uk website is where it should be. So MAF crossed off the list.
I've got a free retest so will use cataclean again and maybe some injector cleaner but i feel I'm more guessing things right now. I plan to plug original chip back in being as that was lumpier. The first failure was due to me rewiring lambda incorrectly, it never had a test with original chip and correct wiring.
Meanwhile I'm trying to find the old file that cam ewith the car for previous MOT emissions (if any!), my wife's moved them somewhere.....
Air filter looks like its not been changed in years - possible cause?
MAF at idle is 33% at direct setting on RG which I believe from Blitz's g33.co.uk website is where it should be. So MAF crossed off the list.
I've got a free retest so will use cataclean again and maybe some injector cleaner but i feel I'm more guessing things right now. I plan to plug original chip back in being as that was lumpier. The first failure was due to me rewiring lambda incorrectly, it never had a test with original chip and correct wiring.
Meanwhile I'm trying to find the old file that cam ewith the car for previous MOT emissions (if any!), my wife's moved them somewhere.....
Air filter looks like its not been changed in years - possible cause?
Edited by Chimp871 on Tuesday 2nd August 18:20
Picking up a IR heat gun today to point at manifold. Thanks for the idea. I've also ordered some new leads and an air filter as I don't know how old they are.
Car goes like it should and last weeks RR confirmed this, 280 bhp/310 lb, so wasn't thinking of a misfire.
Wouldn't a misfire cause the HC to shoot up, way over the max numbers I was given e.g. 500 plus.
Car goes like it should and last weeks RR confirmed this, 280 bhp/310 lb, so wasn't thinking of a misfire.
Wouldn't a misfire cause the HC to shoot up, way over the max numbers I was given e.g. 500 plus.
IR temp gun (£7) gave some interesting results.
It seems that temp readings on exhaust outlet cylinders: 1, 7 & 2, 8 (the corners) are always hot especially 1 and 2 and consistent.
As for the others well the temperature was lower by 100oC on one random cylinder. It kept moving between 3, 5, 4 and 6 and usually just one. Wierd!
I had a new ignition coil and put it on and perhaps it was better but there was still a random low temp cylinder.
FWIW - the old coil, if you shook it, you could hear oil sloshing about whereas the new one (Bosch) you couldn't.
Possible the injectors are playing up. I bought some wynn's injector gold stuff as a cheapo fix to see if there's any st to shift.... Time will tell.
Running out of ideas..... so:
Would worn extenders/leads be a cause of the woes?
Normal for a coil pack oil to slosh about?
Anyone know of temp drop on after the Cat's?
going in for a quick emissions test tomorrow.....
It seems that temp readings on exhaust outlet cylinders: 1, 7 & 2, 8 (the corners) are always hot especially 1 and 2 and consistent.
As for the others well the temperature was lower by 100oC on one random cylinder. It kept moving between 3, 5, 4 and 6 and usually just one. Wierd!
I had a new ignition coil and put it on and perhaps it was better but there was still a random low temp cylinder.
FWIW - the old coil, if you shook it, you could hear oil sloshing about whereas the new one (Bosch) you couldn't.
Possible the injectors are playing up. I bought some wynn's injector gold stuff as a cheapo fix to see if there's any s
t to shift.... Time will tell.Running out of ideas..... so:
Would worn extenders/leads be a cause of the woes?
Normal for a coil pack oil to slosh about?
Anyone know of temp drop on after the Cat's?
going in for a quick emissions test tomorrow.....
Qbee - it's clipped in properly, it'll swivel a little in it's position but its minimal. I did undo it to clean the top of the rotor arm.
Curious to know would knacked HT cables and shrouds cause cut outs - I should add they are magnecor?
Curious to know would knacked HT cables and shrouds cause cut outs - I should add they are magnecor?
Edited by Chimp871 on Thursday 4th August 22:49
Yes, as M50 ends near Ross-on-Wye, about 20 mins from there. I'd be great to meet to get your thoughts/analysis but I'm off camping Saturday for a couple of weeks 
wasted chance.
You got me thinking about 'leads earthing to engine' - boot on #5 is charred and somewhat cracked after touching hot manifold perhaps it's arcing there? Got a couple of old leads to test it.
Would it affect the performance of the other cylinders?
wasted chance.You got me thinking about 'leads earthing to engine' - boot on #5 is charred and somewhat cracked after touching hot manifold perhaps it's arcing there? Got a couple of old leads to test it.
Would it affect the performance of the other cylinders?
I like to close the loop, to help others.....
So went away camping with family and happily forgot about the issues. Got back and changed the dizzy cap and arm. There's still a little/random subtle quick dip in the engine at idle and revving.
Spoke to a recommended local garage (another one) who knew a fair bit about v8's after building several himself for racing. first he gave me some trade only injector cleaner (forte?) the day before the test.
He said my timing of 28 degrees on my cam should be changed to 34 degrees (I've a V8D stealth cam), which I did and well, there's a bit more torque.
He did the mot test and it's now passed
, CO is right on the limit at 0.30%. What I did notice is he didn't trust the rev counter and tweaked revs himself. I'll post the results later.
There's still that engine dip but it's almost impossible to spot unless you've been made paranoid by the other 2 garages
. Fella didn't think it was misfiring but the result of the cam, curious to know if any stealth cam have a perfect smooth engine it there's a still a dip.
So end of saga for now, thanks for help. Can't wait for next year's test
So went away camping with family and happily forgot about the issues. Got back and changed the dizzy cap and arm. There's still a little/random subtle quick dip in the engine at idle and revving.
Spoke to a recommended local garage (another one) who knew a fair bit about v8's after building several himself for racing. first he gave me some trade only injector cleaner (forte?) the day before the test.
He said my timing of 28 degrees on my cam should be changed to 34 degrees (I've a V8D stealth cam), which I did and well, there's a bit more torque.
He did the mot test and it's now passed
, CO is right on the limit at 0.30%. What I did notice is he didn't trust the rev counter and tweaked revs himself. I'll post the results later.There's still that engine dip but it's almost impossible to spot unless you've been made paranoid by the other 2 garages
. Fella didn't think it was misfiring but the result of the cam, curious to know if any stealth cam have a perfect smooth engine it there's a still a dip.So end of saga for now, thanks for help. Can't wait for next year's test
Edited by Chimp871 on Sunday 4th September 19:53
Paulprior said:
Just out of curiosity did the IR gun prove useful?, if so what did you get?
Paul
I don't think its perfect it it just gives you an idea. I found if the laser hit wg a piece of enamel paint it would vary a lot and so you have to take several readings.Paul
Mine showed random temp variance on cylinders 3,5,4 and 6 and would move about all the time. Not all 4 at once just one.
I think there must be better solutions and i read on here v8d using zip ties on exh. Manifold. If misfiring the tie wouldn't melt (as fast, as temp reached 400oC+)
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