swisstonihasher

Help! I've just had new single sports cat 3" fitted and went for MOT, had these readings:

Readings of fast idle =<.30% actual 9.65% Lamb .758 2nd time =<.3 % actual 4.01% Natural idle test =<.5% actual 6.5%

Idle was 2500-3000 revs.

The quick basics of my specs 2.5L, 800 cc injectors, simtek ecu, FMIC, Bosch motorsport pump, uprated FPR...anyone running similar spec and can pass MOT with single cat? At mo, not sure I could pass with 12 cats fitted looking at those readings...

wrxwill05

iTrader: (1)

that does look a bit whack.... is a 100 or 200 cell sports cat? if u look around 100 cell sports car are known for MOT failures.... most places are starting to sell 200 cell cats now..... have you left your 2nd cat on the uppipe as well?

scatty

iTrader: (1)

i think you need to find a friendly mot place in the area....im sure there must be other scooby owners who have this problem????

swisstonihasher

It's a 200 cell I think, but man those readings are high. I think its part of the running with the simtek as idle is up and down, up and down, my lamda sensor (read from ecu wiring) always reads rich. I'm trying to get hold of Bob Rawle for advice as she's booked in for monday as re-take but think emissions will still fail even with FPR turned down on pressure (a trick I did with an old car which made her run leaner).

No idea where, I'm in Bristol but I only know of place up north which I'm never going to visit again for other reasons.

360ste

iTrader: (1)

Be thankful you don't run a GEMS, I spend a hour prior to my MOT correcting the emissions.

swisstonihasher

Spoke to mapper, he confirms issue is with the 285 piper cams, not much chance she'll pass with cat and any ecu including standard one - might just try it though for retake monday as I've got to remove the water injection pump (which is broken), which also means taking cover off ecu.
Could also check for fault codes as might be something else causing her to run extra rich (sure last map she wasn't this bad, lamda readings of .74 when in neutral at 2,500 - 3,000 just cant be rich without boost).

How do you modify your settings to get her through test then? What spec cams do you have and how many cats?

swisstonihasher

Just spent an hour changing the simtek back to OE ecu just as a trial really. Running with same FPR setting, oe ecu has lamda readings of .96 - 1.03 (mainly .97 to 1.01 though) which not great but better than simtek. LED lamda gauge reads rich side of green and sometimes does its rocking motion between high and low green (which means its closed loop if I'm not mistaken). Also when high revs (2,500 -3,000) about the same and not instantly rich like the simtek. I've asked my mapper to see if its possible to clean up the low running more like the oe ecu as to run .76 when in neutral is bad between 1,500 - 3,000 revs (with boost great, but neutral no).

Will see results tomorrow I'm expecting her to be much cleaner but prob still fail by a margin.

Jolly Green Monster

iTrader: (4)

sounds too rich on the map on the simtek as you have found

swisstonihasher

Yup, sure does indicate that, I've emailed Bob R about it to see what he thinks about re-tuning the lower down revs area. Simtek should be able to deal with running same as oe ecu yeh as they both can run closed loop?
I'm sure readings on MOT will be way different and having .76 lamda readings is about as rich as you can get...

Jolly Green Monster

iTrader: (4)

yes simtek runs closed loop etc.. what cams are they? ie. how wild?

Simon

swisstonihasher

Piper 285's, so not mild

What running would you expect from that setup and idle for example?

Jolly Green Monster

iTrader: (4)

slightly higher idle speed.. emissions would be effected if idle low and obviously more gas flow when idle higher but regardless 0.76 lambda is too rich..

swisstonihasher

Fingers crossed she'll pass tomorrow with oe ecu. After that, I'll be talking with Bob about mapping again - do you think its possible to use the 2nd map as an MOT map, ie can it be set to run lean lower down with cat installed with those cams and measure exhaust gas readings?

What would you expect the co2 readings to be when at 2,500 - 3,000 in netural with those cams and simtek? Idle is a little faster but is does bounce around alot, up and down, up and lamda always in last red (very rich).

Jolly Green Monster

iTrader: (4)

if lambda can be correct and the cat is in working order then it should pass...

yes the 2nd map could be setup with cat on and to pass mot etc

swisstonihasher

Thanks for the reply Simon...

I guess since putting old ecu back in and reading lambda from secs monitor and LED gauge with readings of .96 to 1.01 at 2500 - 3000 then exhaust sensor okay? The old ecu hasn't had any engine faults except P0245. If my lambda gauge reads direct from ecu wiring then signal is same as what ecu is seeing I guess.

I'll see what Bob can do re 2nd map, like the idea of a lean run on 2nd with cat if possible, as even if she passes tomorrow, I wouldn't want to keep taken new ecu out for old as bound to cause electrical terminal issues over time, these things aren't designed to be pulled in and out every year lol/

swisstonihasher

On run to MOT test today I'll be doing a rear lambda sensor test as per Bob's guide using :
"As I say happy to play around with the normal idle for you, to check the rear lambda drive at steady throttle at say minus 0.2 bar and above 1200 rpm, around say 2000 rpm, your lambda gauge should be showing disco, if its rich then your rear sensor is failed", I expect it to disco with oe ecu (as it did in the garage all the way upto 3,000) and have a motorway or dual carriageway that is perfect for this light throttle test. Will also advise Bob of MOT readings about 5 ish.

swisstonihasher

She's passed but not sure about a few things...

Both readings for failure and pass tests have:
1, Engine oil temp measurement was by-passed or (2nd attempt) Engine temp measured by gauge - I do have oil temp gauge but its a dual so how do they know what they're looking at?
2, Engine speeds for fast run 2,500 - 3,000 - notes are "not checked", 2nd run "manual check".

When running the OE ecu, I have a secs monitor with displays lambda and it was reading okay-ish apart from idle which was rich. I also have a lambda digital LED display which is wired into the rear exhaust sensor via the ecu loom. Which sensor does the secs monitor, is it the front sensor? I had "disco" at steady revs down the motorway between 1,500 - 3,000 but on the way back the lambda digital was reading 1st or 2nd green which is rich but secs monitor was only reading .96-.99 ish and no lower. Still not same as with simtek in though as she jumps straight to full rich (3rd green).
Bob thinks rear sensor is duff but I'd ideally like to test further before forking out 100 plus on new sensor and find its not that...any ideas?

Jolly Green Monster

iTrader: (4)

the secs monitor uses the front wideband sensor.. as does the simtek and doesn't use the rear one so I wouldn't buy one.

Simon

swisstonihasher

What reads the rear o2 sensor then (apart from my gauge lol) or what's it for? Is it just to monitor the condition of the middle cat when car is standard?
Bob's saying simtek uses rear/oe front so I'm really confused now and not sure I want to refit simtek just yet (as she is that stinky rich in idle and neutral, oe ecu not).

allza

MOT stations have their own oil temperature sensors that go down the dipstick hole. Also they rpm pickup sensors. However you don't have to use them so most garages just skip this step and hence it says on the printout that they have been bypassed.

swisstonihasher

Ah, see, thanks Allza, doesn't sound very scientific though this testing if they dont use their own calibrated kit...or most likely non-calibrated. My readings between first test and 2nd massive but car does smell that different also.

allza

They are always calibrated. However if they decide to bypass say the rpm pickup then they could hold the revs outside of the 2500-3000rpm zone to help it get through, which is better for you!

swisstonihasher

Hmm, like that thinking ...might well of done that as my idle still sucked with oe ecu...fast idle was okay though. Will have to visit them again

Jolly Green Monster

iTrader: (4)

I had assumed it was just rich on the simtek now you had fitted a cat?

The simtek only needs to use the front wideband sensor as the rear sensor is after the cat and used by the OE ecu to adjust/check emissions

Simon

swisstonihasher

Hey Simon,

Mine was complete decat when simtek fitted, had cat put on just before MOT (that was couple months ago now, its been that long going to Newport and dealer lol). I'll await confirmation from Bob and how I can confirm for sure a sensor is fubar before forking out.

Bob Rawle

Simon, you are completely wrong regarding which oxy sensor is used by the E1S02 Simtek for closed loop, all Simtek ecu's use the rear narrow band sensor for closed loop, the front new age sensor is pants actually and is only pseudo wideband, the oem ecu circuitry uses a single hybrid chip to do all the work and that then signals the ecu micro with an output. The OE ecu never uses the rear sensor to "adjust emmissions", where did that thought come from. If you disable the codes and unplug it the ecu does not react at all. The oe ecu uses it as "cat fail" signal. All its closed loop is from the front sensor.

Tony's problem is very probably his rear sensor, the checks he is to do will prove that.

Happy to clarify.

best regards

bob

Jolly Green Monster

iTrader: (4)

so probably rich due to cat fitment

Jolly Green Monster

iTrader: (4)

Bob,
Agree, on the simtek closed loop, sorry Tony.

Simon

swisstonihasher

np.

Just sorting 2nd map with Bob now for MOT runs, will keep 1st map as is with toulene/WI and go for tweak next year with bit more power...know which run I'm looking forward to

Jolly Green Monster

iTrader: (4)

Bob,
Spoke to Andy at simtek as you did yesterday and agree on rear lambda my mistake, they were trying and I assumed they got it working.
Usually map with it off and then turn on and check it works.
I dont agree on oe though.
It checks the changes made on the front lambda occur on the rear.
Although an interesting subject regarding removal.
Simon