K series running issues / possible misfire?

[revilla]

Hi Pete,

 

Answering both your posts and your email on here - my poor brain can't cope with two conversations at once, especially with the same person!

 

Hopefully you're busy fitting your coil packs and all will be well. If not ...

 

Firstly the lambda sensor is in a jiffy bag ready for posting tomorrow.

 

Secondly don't compare your engine on cold startup with that video I posted; the VVC has special valve control which allows it to pull like a tuned engine at the top end but still be docile and smooth at the bottom end, whereas I guess the SuperSport upgrade on yours has hotter but fixed profile cams that will give it more top end but probably a bit lumpier at tickover, and although you see me starting the engine up in the video it was probably well and truly warm already :)

 

If all the upgrades done to your engine are part of the SuperSport upgrade and it had the SuperSport ECU update at the same time, I think its safe to say that the mapping should be suitable for the engine.

 

As for a misfire damaging the lambda sensor; I may be wrong but I find it hard to imagine how it would. I would find it more believable that if it was running lean it would damage the lambda sensor as the exhaust gasses would be a lot hotter, but even then I've no idea whether it might be more than the lambda sensor could take.

 

Another thing to consider; I hadn't put two and two together and connected this thread with the thread on the rev counter that varies wildly with electrical loads. To answer your email points I think the standard K Series rev limit is 7200 but Z&F raise this to 7600 when they remap it, so maybe the SuperSport upgrade may raise it too; I really don't know any more than that. MAybe somebody else could comment?

 

So if it really is electrical loads that affect the rev counter (just check it really does move with the lights on and off, rather than just jumping around at random), that suggests to me that the voltage feed to the instruments may be varying with electrical load. This would either be due to electrical resistance somewhere in the supply (a poor connection of some sort, basically Ohm's law says the more current you pass through a given resistance the more voltage is dropped across it) or poor regulation at the alternator (which would be delivering a voltage dependent on the load placed on it). I know Jonathan got you to check the battery voltages under various conditions and they looked OK, so it's probably not the alternator, more likely a wiring problem along the line. I'd be quite interested to know what voltage the ECU is seeing under different load conditions - if the voltage at the instruments is haywire enough to mess them up, then if the voltage variations are also affecting the ECU it may well mess that up too, especially as a lot of the sensors may be affected by out of kilter voltages (the ECU does try to regulate the voltage down to e.g. 5v for the TPS but significant voltage fluctuations in the supply could cause the regulation to drop out).

 

I'll have another look at the wiring diagrams to see if there any easy points to get a voltmeter onto the ECU circuits to see what is happening. In the meantime one thing you could check would be the security and condition of the engine wiring loom earth point, which is a bolt in the engine bay on the edge of the the bulkhead shelf. It's (one min at least) just a big cross-headed screw with a bunch of black wires on spade connectors. Make sure this is clean and tight.

 

Andrew.

 

Edit to add: OK I've had a look at the engine loom wiring diagram again. While you have the lambda sensor unplugged, start the engine up and with the engine running (it should still run with the sensor disconnected), see it you can measure the voltage between the engine loom earthing screw I mentioned above and Pin 4 of the lambda sensor connector in the engine loom. This is the pin nearest end of the connector which is square rather than round and (probably) has a brown wire with a pink stripe. It's a female connector so you may need to carefully push a little metal terminal of some kind (or the stripped end of a bit of wire) into the hole to make a connection, but be careful as this is a 12v feed so don't accidentally short it out to the engine block! See if the voltage there varies much with the lights on and off etc. This is about as close as you can get to a direct measurement of the voltage supply to the ECU and its ancillary components. If your car has the Main Relay in the MFRU wired in, that wire is on the output side of it so will pick up any problems with resistance in the relay contacts, the supply side of the engine loom and its feed from the main vehicle loom right back to the ECU fuse and the battery. If your car doesn't have the Main Relay wired in, that wire goes directly to the main 12V distribution junction inside the loom which also feeds the ECU directly. Don't worry about whether your car does or doesn't have the Main Relay wiring, it's just a minor variation with slightly different wiring found on some cars to others for some reason.

 

Edited by - revilla on 16 Apr 2014 21:52:24

[Smithy77]

Not winning! New leads and coil packs didn't fix the problem I'm still getting the hesitation with a sharp blip of the throttle, and the resultant pop on the over run after said rev.

 

Revilla, thank you for that lambda sensor, much appreciated.

 

Regarding my rev counter, I am almost certain it is just electrical loads that fluctuate the needle. All the while the electrical load remains constant the needle remains steady. However, and I'm less certain of this, I think I have noticed that for a given electrical load, and a given speed/gear, I have seen the reading vary from one day to another. I could test this further if it turns out to be an important factor...

 

In the mean time I'll check the earth point. I've already checked the earth cable that runs from the battery -ve terminal directly a bolt on the starter motor - presumably there is another earth point to check as you describe? I'll also have a go at measuring the voltage across the lambda connector which I can do before your sensor arrives. What should I be looking for? Does it matter if the engine is hot or cold? Electrics is not my strong point so it sort of went over my head when you started talking about relays - what's the MFRU?

 

I've not mentioned previously but probably worth noting that the previous owner carried out the 'k series click modification'.

 

Soldierin on....

 

Edited by - Smiffy7 on 17 Apr 2014 08:36:38

[Jonathan Kay]

Quoting Smiffy7: 

- what's the MFRU?

It's a collection of relay units, and, contrary to popular belief, the first two letters stand for Multi Function. The relay for the starter solenoid fails in some cars, producing the starter click problem, and the fix, which you already have, is to add an external relay.

 

Jonathan

[CharlesElliott]

Only just seen this thread (and haven't read the full 4 pages).

 

The Megagrad upgrade with metal intake is well known for killing sensors/looms due to vibration. McMillan actually have some sensor mounting pads - and I think reworked sublooms - to address this. The TPS is the usual culprit.

 

On your P0135 error - from memory this is standard on the MEMS, i.e. Caterham didn't update this for the Caterham engine configuration so it always gets thrown.

 

[CharlesElliott]

Old post, but some info here.

[revilla]

@CharlesElliott - Are you sure that is P0135? From memory mine habitually throws P0136 relating to the post-cat sensor (Bank 1 Sensor 2), which I understood was as you say because the ECU wasn't updated to tell it that it hasn't got one, but it doesn't complain about Bank 1 Sensor 1.

[Smithy77]

Quoting CharlesElliott: 

Only just seen this thread (and haven't read the full 4 pages).

 

The Megagrad upgrade with metal intake is well known for killing sensors/looms due to vibration. McMillan actually have some sensor mounting pads - and I think reworked sublooms - to address this. The TPS is the usual culprit.

 

On your P0135 error - from memory this is standard on the MEMS, i.e. Caterham didn't update this for the Caterham engine configuration so it always gets thrown.

 

Thanks, Charles. This seems like quite a pertinent point. It is worth reminding those who are kindly helping my cause that, so far out of everything I had tried, disconnecting the harness from the TPS is the only thing which has made a noticeable improvement to the running of the engine (albeit it made it idle at about 2K rpm).

 

Looking at the post on the McMillan website,

"The new McMM one does have the added benefit of uprated wiring and silicone shrouding to those areas that have shown signs of weakness in the past."

...well I did happen to notice that there is black silicone between the harness wiring and the plastic connector block on this connection to the TPS. Perhaps my loom has partly or wholly had the upgrade? Regarding their comment about a rubber gasket between the IACV and plenum, all I noticed on mine was a rubber o-ring.

 

Quoting Jonathan Kay: 

Quoting Smiffy7: 

- what's the MFRU?

It's a collection of relay units, and, contrary to popular belief, the first two letters stand for Multi Function. The relay for the starter solenoid fails in some cars, producing the starter click problem, and the fix, which you already have, is to add an external relay.

 

Jonathan

 

Ah thanks, I take it this the the black box cable tied on top of the ECU with two big (one extra large) connector blocks going into it?

 

Edited by - Smiffy7 on 17 Apr 2014 10:20:27

[Roger Ford]

Do you know whose car it was, Smiffy? Depending on how many owners it's had, and whether I still have the owner's email address, I may be able to find out if it's had the uprated loom.

[Smithy77]

Roger - YHM

 

Quoting revilla: 

If your car has the Main Relay in the MFRU wired in, that wire is on the output side of it so will pick up any problems with resistance in the relay contacts, the supply side of the engine loom and its feed from the main vehicle loom right back to the ECU fuse and the battery. If your car doesn't have the Main Relay wired in, that wire goes directly to the main 12V distribution junction inside the loom which also feeds the ECU directly. Don't worry about whether your car does or doesn't have the Main Relay wiring, it's just a minor variation with slightly different wiring found on some cars to others for some reason.

Can you elaborate please? Do I need to know which my car has, and do I need to do/check anything here?

[Jonathan Kay]

Andrew: Is there a convenient way of jumping a battery live feed into the ECU for diagnostic purposes?

 

CharlesElliot: Can you add anything on diagnosing a fault with the TPS or its wiring?

 

Thanks

 

Jonathan

[revilla]

Pete,

 

Can't help but feeling we are getting carried away looking for something more complex than it really is (which is easy to do, especially when you can't actually see and/or hear the car, and - please don't take this the wrong way - we are relying on descriptions of the problem from someone who is unfamiliar with the "normal" behaviour of these engines) ... so, going back to basics and your original post regarding symptoms:

 

1) The engine requires a lot of cranking before it fires, needs to turn over for 2-5secs before firing. 50% of the time it'll fire up ok, 30% it'll start but almost conk out before regaining idle, and occasionally it wont start and will need a little bit of throttle to get going but then idles fine. This happens when engine hot or cold. This happened from when I bought it but was told it was probably due to having 95RON fuel in it. I have run it on Tesco 99RON ever since but it hasn't helped.

 

OK, this doesn't sound typical, certainly not if my two engines are anything to go by. So we have poor starting and poor running when cold.

 

2) The car is extremely difficult to drive smoothly before getting up to decent temp, particularly noticeable in 2nd/2rd gear getting to the end of my close. Very bunnyhoppy and almost need to ride the clutch slightly to drive smoothly. Once down the road and warm not so much of a problem. Again, happened from when I got the car, assumed it was part of the character and a case of TADTS, but now other symptoms have cropped up I'm guessing the severity of the un-drivability is probably linked.

 

So poor running when cold again.

 

3) When I'm running at mid revs in say 3rd gear and I go to slow down, as I dip the clutch to change down a gear I get little pop (deep tone, low volume) from the exhaust just as the revs start to drop. At first only noticed when engine cold, but seems to have got more frequent, and to a lesser extent when warm too. Sign of a misfire?

 

Mine didn't do this on a standard ECU but when Z&F remapped it, they added this "overrun burble" as an optional desirable feature (sort of mimics good old fashioned carburetor behaviour for a bit of character)! Given the tuned state of your engine, I don't think this is anything to worry about. It's certainly not a "misfire".

 

4) When idling (and also at higher revs while stationary), if I give it a sharp blip of the throttle, it will hesitate for a split second before then revving up fine a freely. Sounds a bit like a "brum.....brooooOOOOOOMMMM!". However, if I blip the throttle progressively it will rev up smoothly - "broooooOOOOOOOOOOMMMM!" toothy smiley Again, sign of a misfire?

 

Again, thinking about it, from idle - mine does that too. From higher revs the throttle response is sharp and immediate, but stamp sharply on the pedal from idle and it does hesitate a moment before picking up. I guess the very sudden change in conditions in the manifold from almost vacuum to atmospheric coupled with cylinders that are only firing a few times a second at idle just means it takes a moment to catch up and settle. Don't worry about this, at least not for now.

 

5) When I perform the revving described above while out of the car and observing the exhaust, with a smooth progressive rev there is no smoke. With sharp revving inducing the hesitation, I see a puff of dark smoke (un-burnt fuel?). The quicker/sharper the rev, the more pronounced the hesitation and the bigger the puff of smoke. Misfire?

 

Never noticed visible smoke from mine when blipping it, but i) probably not looking at the exhaust at the time and ii) my engine isn't tuned in the way yours is. May or may not be indicative of a problem. Again though it doesn't sound like a "misfire" is an appropriate description - sounds more like momentarily rich mixture.

 

6) Over the last 100 miles or so I have noticed that the car has lost a bit of its punch above 4K rpm and it's now obvious it wasn't just my imagination. For the first time today

 

OK this doesn't sound right, I would expect a tuned engine to come into it's own above 4K.

 

Idle seems quite lumpy and almost diesel engine like sound, but I've put that down to the cams and solid lifters more than related to this issue...?

 

My engines are VVC. Their special trick is that they can act like tuned engines when they need to then tune their cams back to be docile as a Ford Fiesta under low load. Your engine doesn't have that special trick up its sleeve, so it is in highly tuned mode all the time. I've only ever really listened to one highly-tuned K Series with sporty cams etc. idling and it was, compared to any other "normal" car, very lumpy and rough indeed. This may just be the character of your engine, so I would discard it as a symptom for now.

 

7) When switching off the engine it will continue to run for approx 2secs after turning the key. This has happened since buying the car but thought nothing of it.

 

This one has already been explained. Quite normal for these cars. I discovered when building my spare engine that there is another contributing factor which is the alternator continues to power the ECU through the alternator warning light - I put a nice big bulb in for this on my test rig and the engine would run on for ever after switching off until I had to pull a fuse to kill it. With the wattages used in the car it's normally only a minor contribution to the problem but one other member recently had to fit a diode to cure this when his engine was running on from this same backfeed. So nothing to worry about here.

 

8) Only noticed this once, about a week or so ago, but on this particular journey I waited until the engine was up to temp (80deg indicated). I then gave it a spirited blat through 2nd and 3rd and 30secs later the temp gauge read approx 50deg. The reading then gradually stabilised at 80deg.

 

Yes this one worried me when I first got my car. The K Series has a funny cooling circuit with the thermostat in the return from the radiator, rather than in the hot water feed to it, with a bypass hose feeding hot water to it via the heater. You go for a "spirited blat", then engine starts to heat up but the rush of air over the radiator cools all the water it contains nicely, then the hot water through the bypass hose causes the thermostat to open and in rushes a bucket load of cold water from the radiator. You can get into conditions where the temperature cycles up and down quite alarmingly (until you understand why and that it is normal). There are various modifications you can do to the cooling circuit (remote PRRT, cooling circuit mod written up in a recent issue of Low Flying etc.) to make it more "normal" and stable. These may well be worth doing as the cycling of temperature isn't that good for an engine that whose main weak points are cooling-related, but to be honest I haven't done anything to mine. It only seems to do it noticeably at this time of years when the outside air is still so cool. Actually thinking about it, there is a little modification, well documented on here (do a search) that involves drilling a small hole in the thermostat to allow airlocks to escape and make it easier to refill the coolant. I did this and since then I've not noticed the temperature cycling at all, so maybe that allows just enough bypass flow through the radiator with the thermostat closed to settle it down.

 

So what are we left with:

 

Poor starting.

Poor running when cold.

Possibly running a bit rich at times.

Lack of top-end performance.

 

I would definitely stop looking for a "misfire" as such. This is something else. It still seems most likely that it is all caused by the ECU not getting a correct read of engine conditions from it's sensors. Sensors that spring to mind would be coolant temperature (if it doesn't know it's cold it won't increase the fuelling, akin to old fashioned "choke", so will be hard to start and run poorly until it warms up), throttle position (still sounds like a prime candidate to me, if the ECU doesn't know where the throttle in it will get things all wrong, would also means the ECU had more difficulty in picking up the fast blip so could exaggerate the normal slight hesitation), manifold air pressure and temperature (again silly readings here will just cause the ECU to get the fuel and ignition wrong) and lambda sensor (already suspect, CharlesElliott may be right and this may be red herring, but could cause the ECU to over or under-fuel if giving silly responses).

 

If your crank position sensor was completely dead the engine wouldn't run. There can be problems with the screened cable picking up interference from the ignition circuits but with coil-on-plug EU3 it's most unlikely. If your cam position sensor was duff the engine might switch injection mode and go into limp mode but that would definitely show a DTC code, so I think we can rule that out. That about covers them all.

 

When are you expecting the CanScan to arrive? I think seeing the actual numbers the ECU is reading from the sensors will either point the finger at one or more of them or rule them out so we can look at other things, but until we get that info we are in the dark and dreaming up complicated explanations. It will probably be something small and silly.

 

I've got a few sensors in my spares box at home that will fit (most of yours will be the same as mine, especially given that you have upgraded to the aluminium manifold). I'll hold off posting the lambda sensor today so I can slip a few spares of the other parts in the bag and post tomorrow. I've got spare throttle position sensors and manifold pressure and temperature sensors for sure. They are second hand eBay jobs but should be good and coupled with OBDII data we will know for sure.

 

Andrew

 

[revilla]

Regarding the MFRU and Main Relay - forget it, not really relevant! I wrote an article for Low Flying a few months back describing a more elegant mod for the K-Click. Several people contacted me afterwards to say their wiring didn't correspond to what I described, so I looked into it in some detail. One of the relays in the MFRU is called the "Main Relay" and allows the ECU to completely switch off the power to the injectors, coil packs etc. Some cars are wired with this relay in use, some (like mine) are wired without it, so these components have a permanent 12V feed. the ECU controls them by grounding the other side. the only idea I could think of as to why some cars are wired one way and some the other is i) the relay has the advantages of eliminating any possible leakage battery drain and makes the electrics "safe" when switched off and ii) the starter relay in the MFRU fails regularly, the relays are all identical so maybe the main relay was experiencing failures and they decided to do away with. But I don't really know. It isn't anything you need to worry about for this.

[revilla]

Andrew: Is there a convenient way of jumping a battery live feed into the ECU for diagnostic purposes?

 

Not easily without chopping wires. The fault could also be on the earth side.

 

CharlesElliot: Can you add anything on diagnosing a fault with the TPS or its wiring?

 

Sorry to cut in but - once the OBDII scanner gives us live data, it will be fairly easy to see if either the TPS or its wiring or connectors are misbehaving.

[Jonathan Kay]

Thanks

 

Jonathan

[CharlesElliott]

Back from my meeting 😬

 

TPS: Once you have data, as has been mentioned, it will be easy to see what is going on here.

 

IACV: Another potential culprit, at least when cold.

 

P0135: Yes, you could well be right, I just made an assumption. But the use of lambda is only when the ECU is in closed-loop mode. So I wouldn't expect it to be the cause of a number of the issues here (and you can just unplug it to see if it makes a difference).

[CharlesElliott]

Your description definitely looks like TPS first, then IACV to me.

[CharlesElliott]

If you can drive to Weybridge, I can take a look and have all the diag equipment 😬

[revilla]

I'll stick a spare IACV in the jiffy bag too 😬

[Smithy77]

Quoting revilla: 

Pete,

 

Can't help but feeling we are getting carried away looking for something more complex than it really is (which is easy to do, especially when you can't actually see and/or hear the car, and - please don't take this the wrong way - we are relying on descriptions of the problem from someone who is unfamiliar with the "normal" behaviour of these engines) ... so, going back to basics and your original post regarding symptoms:

 

6) Over the last 100 miles or so I have noticed that the car has lost a bit of its punch above 4K rpm and it's now obvious it wasn't just my imagination. For the first time today

 

OK this doesn't sound right, I would expect a tuned engine to come into it's own above 4K.

 

You missed off the second half of that symptom by the way, which may add to it's weight as a fault....

"Over the last 100 miles or so I have noticed that the car has lost a bit of its punch above 4K rpm and it's now obvious it wasn't just my imagination. For the first time today on the way back from work I could feel it misfiring slightly if I put my foot down on the motorway in 5th gear"

Don't know if that affects your assessment in anyway...? Not sure if it's best described as misfiring or hesitation

 

Quoting revilla: 

4) When idling (and also at higher revs while stationary), if I give it a sharp blip of the throttle, it will hesitate for a split second before then revving up fine a freely. Sounds a bit like a "brum.....brooooOOOOOOMMMM!". However, if I blip the throttle progressively it will rev up smoothly - "broooooOOOOOOOOOOMMMM!" toothy smiley Again, sign of a misfire?

 

Again, thinking about it, from idle - mine does that too. From higher revs the throttle response is sharp and immediate, but stamp sharply on the pedal from idle and it does hesitate a moment before picking up. I guess the very sudden change in conditions in the manifold from almost vacuum to atmospheric coupled with cylinders that are only firing a few times a second at idle just means it takes a moment to catch up and settle. Don't worry about this, at least not for now.

This could be a bit of a spanner in the works is this is the main symptom that I have been measuring any 'improvements' against And one which I had thought had got worse recently - could be in my imagination though! I didn't take it for a drive last night after fitting the new leads/coils; I just ran it stationary until warm and tested it with some sharp throttle blipage. No improvement so ended it there.

 

Edit to say: Thinking some more about the above 'symptom' I'd be reluctant to completely forget about this. The reason being is that in recent driving I noticed a similar hesitation while out on the road too; If I'm accelerating hard through 2nd/3rd/4th, at the point of changing up and jumping back on the throttle pedal I began to notice a hesitation for a split second. I can remember, for the first few days after picking it up when it was running sweet, this hesitation wasn't there. I would change up a gear and get a clean, crisp and sudden thrust the moment I jumped back on throttle. It was one of the things which I remember sticking out as a 'wow factor', so I know for sure that this has been affected.

 

The new scanner was marked as dispatched this morning, so with the Easter holidays I'm probably looking at Tuesday for that to arrive. Thanks again for the generosity of sending all your spare sensors! When doing my sensor hunting I was able to locate most but I couldn't find the manifold air pressure/temperature or the crank position sensor - is it easy to describe their location?

 

Edited by - Smiffy7 on 17 Apr 2014 13:45:47

[revilla]

Pictures from Google:

 

Manifold Pressure / Temperature sensors are normally one combined sensor on the aluminium manifold like this:

 

http://i277.photobucket.com/albums/kk68/ZSCentral/Chris/map02.jpg

However sometimes there can be separate green IAT sensor on the runner from the manifold down to the rearmost cylinder like this (a leftover from when Rover were using up old EU2 castings on early EU3 engines, your engine will either be wired to use one or the other):

 

http://i8.photobucket.com/albums/a17/krisxf/20121107_132906.jpg

 

Not a very good picture but the crankshaft position sensor is low down at the back of the engine on the right hand side like this:

 

http://www.mgfcar.de/sensor/dkcp_3901_t.jpg

 

Edited because I made right cockup of the image links ☹️

 

Edited by - revilla on 17 Apr 2014 12:28:13

[Smithy77]

I probably should have also mentioned, after fitting the new coils and leads last night I was optimistic at first. Although it still cranked for about 3-4secs before starting, when it did start it started easily and it initially sounded a bit smoother at fast idle - less spluttery. As it warmed up a bit the idle slowed and it resumed its more lumpy idle, but as discussed above, this is probably a normal characteristic of my engine. I then blipped the throttle and the hesitation was still very much there and I thought bollocks, it's not fixed. Maybe I should take it for a spin tonight...

 

Edited to say I have made an edit in my previous post in bold

 

Edited by - Smiffy7 on 17 Apr 2014 13:46:24

[revilla]

Pete,

 

A little bag will be in the post tomorrow containing the following:

 

http://www.revilla.plus.com/Sensors.jpg

 

Hopefully something in there will do the trick. Some bits I sent two of because they are not really tried and tested, no reason to believe anything wrong with any of it though. May take a few days to reach you with the bank holiday. Probably best to wait until you've got the scanner and see what it says first before touching anything further. By the way, if you try to swap the ECU temperature sender, unless you are very deft with your thumb over the hole, you will lose some water and get air in the cooling system, which will probably go straight up into your heater and get stuck. Next thing we will be dealing with overheating and no circulation. Getting air locks out of these things is a whole topic in itself. We don't want to be going there right now - trust me! Don't swap it out unless the scanner clearly shows silly temperature readings.

 

Andrew

 

Edited by - revilla on 17 Apr 2014 21:00:34

[Smithy77]

Legend!

 

Yeh I've read all about the perils of the k series coolant system. I won't be opening it up unless I have to!

 

I've not long got back from a 40min drive to Asda and back. I was with SWMBO so I wasn't able to drive it 'properly'. Although it's certainly not running perfectly, a few things seemed a little better. Driving out of my close seemed a lot easier/smoother, however, I had it running for a few mins not long before we set off so the engine was luke warm and probably not a fair test.

 

When coasting in gear (2nd & 3rd mainly) and with a small throttle application it used to give quite a harsh jerk, no matter how cute you were with the throttle. That seems to have got a bit smoother.

 

Driving at 70mph on the motorway I put my foot down and it still felt flat with a kind of rattly exhaust note once you reach 80mph, so still hesitating/misfiring there.

 

A couple of observations about the rev counter... I previously said it only fluctuated with changes in electrical load, well I notice it also does it when ticking over. The needle will bob up and down in time with the lumpy idle if that makes sense. The other thing I noticed, and only by virtue of it being dark, was that on tick over I noticed that the red alternator light (far right) on the rev counter very faintly flickers, again it seemed to be in time with the lumpy idle. Does this give any further clue to the problem?

 

I doubt I will do too much over the weekend as I have a stag-do Sat/Sun so will probably come on after that if there are any further developments.

 

Have a good Easter all!

[revilla]

Pete,

 

The lumpy idle of a tuned engine is just a poorly regulated idling engine speed, which fluctuates up and down. As the job of the tachometer is to indicate engine speed, one would hope it would go up and down in time withe idle speed. It's just doing its job 😬

 

At the low points of the cycle, the alternator probably won't be spinning fast enough to be charging the battery, so the warning light may flicker. Again, nothing to worry about 😬

 

I still think that the things to focus on are poor running when cold and lack of top end power and I still think some kind of sensor is the prime candidate, giving the ECU duff information.

 

If I were you I would go and enjoy your stag weekend stop worrying about the car until the CanScan arrives, whenwe will have a lot more convrete information to go on.

 

Have a good one!

 

Andrew

[Smithy77]

Hello all, I hope you all had a good Easter! I'm still alive so I'm guessing the stag-do went ok 😬

 

Quoting Roger Ford: 

NGK PFR6N-11 are correct spark plugs. These or Rover NLP100290 are mandated for Super- and Mega-graduate cars. BCPR7ES might be OK as well but the ones you have in there are not incorrect.

 

Thinking a little more about the above I have the BCPR7ES plugs on order and were approx 1/3 of the price of the PFR6N plugs. By all account both plugs are tried and tested in the k series but are there any notable differences between the two, both physically or performance? I digress....

 

Quoting CharlesElliot: 

If you can drive to Weybridge, I can take a look and have all the diag equipment 😬

 

Charles, thanks very much for your generosity, it's much appreciated. Weybridge is probably 1.5hours drive for me and I wanted to avoid running the car in its current state to avoid further problems. I have also just received my new OBD2 scanner which should give me all the live data to help us diagnose the problem.

 

I'll report back tonight, hopefully with some useful data readings

 

Edited by - Smiffy7 on 22 Apr 2014 11:53:55