General Emissions MOT fail

[bungler]

Hello folks, so the Sei failed miserably on it's emmisions, CO was off the scale and HC was three times the limit, Lambda was at 0.65. When I had a look round the TB I noticed the fuel return pipe was broken off completely. I don't think it could've been like that at the test (pretty sure they'd notice all the fuel pissing out and fail it for that) but it could easy have been weeping, I fixed that, but she's idling rough as dogs nuts now, sounds like it's misfiring.

The head was recently swapped for one from a Punto 60 and there's no signs of HG failure, comp test was even across the cylinders last time I checked, I don't think it's that, but the exhaust does smell a bit of burnt coolant, took her for a run to let the ECU relearn, I just fitted a chip, I can't really tell if it feels down on power since I haven't driven it for so long, felt a bit gutless at high revs, but I've been driving a Celica 190 for the last while so I suppose it would.

Any suggestions? I'm thinking of getting an OBD reader from ebay to see what codes come up, or start changing every sensor on the engine. I checked for spark tonight and that seems fine, no1 was maybe a little weak.

 

[Pep0]

borrow a multi meter check the resistance of the coolant temperature sensor
but did it idle ok before?
try Redex in petrol as well mine gums up after a few months idle

 

[rallycinq]

Refit the standard chip for starters, then check the timing. a few teeth out and it will run, but like a burst arse..

Cheers

D

 

[bungler]

I was thinking timing myself, can't wait to take that cover back off, I don't like having skin on my knuckles anyway.

 

[Pep0]

I was thinking timing myself, can't wait to take that cover back off, I don't like having skin on my knuckles anyway.

only remove no 1 plug and top cover use a knitting needle in plug hole for TDC

 

[bungler]

right I'll do that, but there seems to be 2 marks at the crank pulley. The tech manual say's to line it up with the corner of the backplate web, but I have a mark a little further down as well.

Edit : Doh, just ignore that

 

[bungler]

borrow a multi meter check the resistance of the coolant temperature sensor
but did it idle ok before?
try Redex in petrol as well mine gums up after a few months idle

I have a multimeter, don't really know how to use it though, does the sensor not need to be plugged in when I do that? It idled better before, but it wasn't perfect.

Timing checked and checked and checked again, it's not that, compression results were about 70-65-70-70 dry 70-75-70-90 wet. Plugs caked in soot, so I'm pretty sure it's a fuelling problem, just can't figure out what the problem is.

 

[fingers99]

Engine temp sensor or -- if the car takes ages to heat up -- stuck open thermostat.

 

[rallycinq]

multimeter set to resistance (ohms) then check the reading across the two pole temp sensor and check against the nominals for the given temperature...however...if the car is running that rich the O2 sensor should be seeing it and trying to do something about it.

Is the management light on?

Cheers

D

 

[bungler]

No management light on, it did come on when I was pulling plug leads so it works, makes me think the problem is mechanical more than electrical. I had the coolant sensor out but couldn't get any readings from it with the multimeter, maybe needs new batterys.

 

[Pep0]

Hi

Go to pound land for batteries for multi meter and kerosine, i.e. heating oil or barbecue fire lighter, or Halfords for redex if you wanna pay more.

Added 25 mle of the kersosine to tank and 5 litres of petrol..

Check level of oil on dipstick and sniff it if it is higher then you expect, if higher dont start engine.

Before you use the ignition key for the first time in morning lift the air cleaner off and turn on the ignition until the pump stops whirring, then ispect the throttle bottle for any petrol, if there is any remove the injector and leave in neat kereisone over night, or fit another injector if you have one to hand.

The kerosine will dissolve any gum from storage, my auto will gum after 6 months...

If the injector is ok it should not leak petrol while the pump is priming, the injector.

Measure resistance of temperature sensor cold and hot in place on the auto, i.e. measure run engine until warm measure again, only disconnect the sensor connector to measure resistance. Note both readings on back of fag packet

There should be a big difference in resistance and both readings should be near the nominal values which are somewhere on the site.

When you start the engine the heater hoses should get real hot while the rad hose is cold then the rad hose should get hot, if the rad hose does not stay cold for a long time replace the thermostat.

If the auto is running rich enough to get bad MoT fails the ECU light should be on so you may have two faults, but Id not pull things at random that is asking for three....

Are you sure the throttle body connectors are correct if the petrol return was disconnected it should pee petrol like it was in a pub loo.

Noel

 

[blu73]

Just take the plug off the sensor (its the blue one on the inlet manifold) and measure the resistance on across the pins, you should see the resistance dropping as it warms up, should be getting results as follows..
10kΩ @ 0°C
5kΩ @ 20°C
10Ω @ 60°C

If the resistance is too high or just doesn't change then the ecu chucks more fuel in (ie, auto choke). Alternatively perhaps the car just isn't warming up properly (stuck open thermostat) so if the sensor appears to be working whip off the thermostat and check its not stuck - to test chuck in a pan of water on the hob, it should start opening at 85°C and be fully open by the time the water starts boiling.

Also, worth checking all the vacuum lines for splits/cracks considering the fuel line was cracked - one would imagine other hoses are on their last legs as well. In particular check the hose to the map sensor, and that all the vac lines on the rear of the throttle body (nice picture of what is what there in the guides).

You might want to buy a set of new plugs, at the least clean the existing ones up and check the gaps, nice strong spark will help no end - maybe new leads as well depending on how old they are..

That should keep you busy for a bit, report back what happens.

 

[bungler]

Well that's a list of things to do indeed, should get on to that in the next couple of evenings.

RE fuel return pipe - I'm a bit miffed the garage didn't notice that during the MOT, but I suppose they wouldn't have been looking round there when doing the emissions, and it doesn't leak when the systems not in use obv.

Rest of the pipes on the TB seem OK, the plugs are brand new, BKR7EVX, I might stick the old plugs back in, see if that helps any.

 

[blu73]

It shouldn't take that long really, as long as it takes for the car to get from cold to hot to test the coolant temp sender.. You've checked the vac hoses already.. And the thermostat will probably be ok if you car gets to the point the radiator fan starts cutting in and out as it should, in which case don't worry about it. But its never a bad thing to look after your cooling system, drain, flush, refill and bleed is a half hour job that should be done annually really - a job for one sunny afternoon (hopefully we will have one of them again one day).

Also, thats not the right heat rating that plug, from having a quick search online for NGK i would use BCPR6ES in a stock sei. Thats what EuroCarParts, GSF & Halfords websites say you should use anyway..

here is a nice little link explaning how the NGK plug numbers work. http://www.sparkplugs.co.uk/pages/technical/NGK-spark-plug-code.htm

 

[bungler]

I know it's a colder heat rating, I bought them after reading an article about tuning the FIRE engine on here, should really have got it running right first.

 

[Pep0]

I know it's a colder heat rating, I bought them after reading an article about tuning the FIRE engine on here, should really have got it running right first.

Why did you replace the head?
What else is different?
A hotter plug might be needed on a track day.

 

[bungler]

I changed the head because I found one with an 899 cam in it at my local scrappy, I also wanted to try my hand at smoothing out the factory defects with a dremel. I also had some signs of an HG failure, and I like taking things to bits.

Nothing else different. Still not had any time to do any work on, long weekend though

 

[Pep0]

Hi

Thanks for info, cant see why the head or cam would have made a difference.
Did you swap the chip as David suggested earlier, I have had bad (faulty) semi conductors?
I thought about a higher lift cam as well but I was going to just swap cam shafts.
Good luck over the weekend.

Noel

 

[ycming]

None of the chip that was made for the 1108 engine (McKritch, Gazzaman, Chip2Race) will work probably on the 899!

Defo change it back.

 

[blu73]

do you mean properly rather than probably there young Ming?

Besides, i thought this was a sporting....?