Couple of k10 ponderings!

[Daveyboy20]

Hi guys, if you missed my introduction thread I've recently saved a k reg 1.2 Micra from the crusher! :grinning:

Been using it as my sensible daily for a couple of months now just got a little issue I was wondering if any k10 experts may be able to shed some light on?

I spotted that it has electrical plugs all over the engine which I thought was highly unusual for a Micra, then I saw it had a cat and a lambda sensor - then some random pipe linking the exhaust manifold up to the inlet... The more I looked the more I realised it was a bit more advanced than the 1.0 Micra I had as a student!

Its been a bit 'hesitant' so after a search I found a thread about removing the EGR crap and the inlet to exhaust oxygen malarky so I've done that and to be fair it's much better! It's also got new plugs and leads and had 2 full tanks of super unleaded with redex fuel treatment as well as a whole can of carb cleaner.

When it's stone cold, a press of the throttle to the floor and then holding it halfway and it starts instantly and idles well. It's just it's still slightly hesitant when driving on partial/mid constant throttle. It also doesn't seem to rev with the characteristics of a carbed motor - it doesn't instantly drop down after a quick blip in neutral, it slowly drops as if it was fuel injected... Could this be linked to the slight 'hesitancy'? It's only got 44000 miles and to be fair starts and runs like a dream but I like to play till things are spot on and I'm wondering if the symptoms sound like any common problems you lot have come across? It did 65mpg on a recent long trip! And the heater is absolutely awesome! It's called William by the way...

Cheers guys (Y)

 

[esox]

Who your making a nice clean burning 1.2 into a petrol smelling original k10 remember when it comes to MOT the car will need to pass its emmisions within the model's limits so dont remove too much.

 

[nexussteve]

I removed the EGR on my 1.2 Super S engine and it was better! Sod fuel economy!

 

[frank]

the egr system was for nox emissions tho surely ? (not tested for)
but the vacuum advance piping is crutial on the later k10,s i believe

 

[Daveyboy20]

It's just the EGR and AIV I've disabled and its easily reversible if i wish. It definately runs better without them... I found the advice here by the way

http://www.micra.org.uk/threads/42296-Guide-To-Disable-EGR-amp-AIV-Without-Removing.?highlight=

 

[porkpie700]

Oh ho some one has used my guide and done it the easy way lol.
The delayed return to idle is normal, the carb is fitted with a dashpot which stops the throttle from slamming shut and creating an un-usabley rich mixture, which would be blown into the cats and damage them. Removing the dashpot makes the car kangaroo when you let off the throttle, which makes you look like a learner driver when you pull up at traffic lights, which ain't cool. You're driving an ECC model and yes it is a world apart from the dirty burning 1.0L's.

The timing and carburattor are controlled by the ecu under the passenger seat. There is no vacuum advance frank, and the whole system is a 3-way sytem for HC and CO2 emissions, just like the k11. If your car was manufactured in or after August 1992 (K reg) then it's mandatory that these systems work, as you are bound by the same emissions laws as all new vehicles.
The hessitation you mentioned, does it feel like a slight hunting? Almost like someone is dabbing the throttle even though you're holding it perfectly still? That's the computer trying to find the best settings for the way you are driving, it's perfectly normal.
When starting from cold you should press the throttle to the floor twice, then get your foot off it and turn the key. After the car has idled for about 10secs just dab the throttle to knock the choke off the first cam, it should idle at about 1200 - 1400rpm untill warm.

Super unleaded is wasted on the ecc model, it's designed to run on 95RON, using a higher rated fuel will give you no benefit unless you re-tune your engine to take advantage of the extra octane numbers. Even the manual states that there is no advantage to using super unleaded.
The key thing to keep your ecc motor running sweet is to make sure that ALL of the vacuum lines are in perfect condition, just a small leak can cause a number of systems to malfunction, as well as knocking out the mixture. It sounds to me like you motor is running perfectly normal and is very healthy, all you need to do is keep it that way.

 

[Daveyboy20]

Cool, cheers for the info mate - I won't waste any more on high octane fuel for one! Appreciate the thread, very easy to follow and clear and definitely made it run a bit nicer so cheers for that!
:laugh:
The hesitation does feel like hunting but it's slightly more pronounced than I fear the ecu changing carb settings on the fly would feel like? Unless it is relatively obvious when it does it? It almost feels like the condenser is worn and the spark is a bit inconsistent but it's only when light constant throttle and completely clears when accelerating. It's not really a problem because it runs like a swiss watch and sounds like a sewing machine (apart from the back box hanging off!) it might even be down to a lack of back pressure? Anyway, thanks again mate (Y)

 

[porkpie700]

Dude, it IS THAT OBVIOUS :laugh:
It will do it as soon as the lambda sensor is warm enough to start sending readings to the ecu, so they usually run smoother when on choke. You don't have a condenser dude, that's for old crap points type ignition which was only used up to 1988. The little doodar next to the coil is actually a supressor, to stop electrical interference travelling through the wiring. The timing is completely electronic, using an LED/Photo Reciever crank angle sensor inside the distributor to handle the timing, just like the fuel injected k11's.
They do need their back pressure, the ecc back box has a smaller diamiter exit pipe than the non-cat models.

So forget about points, condensers & vacuum advance, none of that crap is used on the ecc model. It's all computer managed with the aid of a few vacuum valves (used to control the emmisions devices). The way your car runs is the way it always has, same way every ecc i've been in drives. So forget about all those old carb models you might be used to, the ecc is a different animal, and it sounds like you have strong one.
(Y)