1.8 16V K-series unusal MISFIRE

hello landyzone


ok for the people who have decided to have a read and hopefuly help with my problem, i will say straight away this is not the normal headgasket misfire from te crappy K-seires that usualy occures and seems alot more complicated, so ill do my best to explain the problem

i own a 2003 freelander 1.8 16V K-series with 54000miles which i bought from a friend from work which was supposed to be knackered with the usualy viscous, IRD, and rear diff knackered but it turned out to be an easy fix, just the rear diff mount and a new front CV joint. BUT since buying it, its always had a nasty misfire, either reving it in the driveway or out driving it and it can be easily repeated....

first off it doesnt misfire when idling or reving slowly and i can rev it all the way to 6000rpm if im gental, but what ever speed im doing, any gear, any RPM, any engine temp, if i accelarate a little bit too hard (even in nautral) it will start missing and feels like power is starved as it feels like the brakes are slightly on..... everytime i plug my computer into the ECU it comes up with code P0302 (misfire cylinder 2) some times code P0313 (i think) which is misfire due to low fuel, but ive noticed it only says this when my fuel tank is realy low and it thinks its due to that so the p0313 code should be ignored.....

ok now for the things ive replaced and tested, in the order i did them in...

• i of course did a full service when i bought it with engine flush new oil and filters
• i changed the 4 spark plugs and set the gap to 1.0mm
• changed both coil packs
• did a compression test on all 4 cylinders and all came up with great results (15 bar)
• did a sniffer test on the coolant and it stayed blue, so no HC's in the coolant
• swaped the 2 HT leads for 2 high performance ones off my V8 which do work, but still misfired so put the original leads back on
• replaced the exhaust manifold gasket because it was blowing slightly and the oval gasket at the bottom of the first cat
• swap all 4 injectors for 4 low mileage 4.4 range rover V8 (bmw) injectors (yes they flow more fuel but the ECU did its best to sort it out as my computer said the fuel trim was -25%) didnt help anyway....
• bought second hand fuel rail with 4 standard injectors, but didnt help at all, so took fuel rail off but left it connected to the fuel pipe to actualy watch the fuel spray pattern and to see if it was firing sequential and not batch firing.... all looked great and even got some video of it
• unplugged the pipe from fuel rail to do a pressure test... 3.5 bar which is normal... then got a T-piece into the fuel pipe so i could do a pressure test while the engine was running... 3.5 bar at tick over and 3.5 bar while reving upto 4000rpm which is great
• took the inlet manifold off and checked for leaks and replaced the rubber gasket aswell
• did vacuum test on the inlet manifold and it stayed at 20 inhg and didnt fluctuate, when reved instantly lost vacuum went to about 5 inhg and when the throttle was shut it shot upto 25 inhg and settled back to 20 inhg, so looks great with no leaks
• checked timing belt to make sure everything was timed up ok and everything was.... i even took No1 spark plug out found TDC, attached a timing wheel to the cranck pulley and checked inlet cam shaft was opening at 12degrees BTDC and exhaust opened 52degrees BBDC and all was fine

• i turned all powered items on and heaters on to test the idle valve and the tick over stayed the same, i unpluged the idle valve then turned off all the power items and the revs increased, so i plugged it back in and it settled back down... looks fine
• unplugged MAP sensor and the revs went nuts and seemed to want to kill the engine, then it must have gone into a base setting as the idle settled. also looked on the computer and the KPA was at 30 when ticking over when it was plugged in but it went to 7kpa when it was unplugged, it also shot upto 92kpa when the throttle was fully opened up so all looks good
• lambda sensor was fuctuating nicely on the comp going from 0.02V to 0.8V but when unplugged it went to a base setting of .047V constant so that looks good
• unplugged throttle pot and reved it and it nearly died as it didnt no there was going to be a sudden rush of air, also on the comp and a volt meter it read 0.3V to 4.7V smoothly with no jumps, so that looks good
• unplugged the cranck sensor and it died instantly and wouldnt start, so its getting a reading from that otherwise it wouldnt run
• unplugged cam sensor but didnt do anything noticable, but when sticking a volt meter on it, it does get a reading and the frequence does increase when reved, but i am suprised no fault codes come up on the ECU when its unplugged

Adam
Same engine as mine.
Is the air filter choked?

nope, was change the day i had it, plus ive ran it with no air box on and no difference

maybe you have a faulty coil pack,even new ones can go bad,if its good,i say you have a problem with your ecu,

Looks like you tried a lot of stuff, iv still got a few ideas to add. All my k-series experiance is in my Elise, they are basically the same but sorry if anything is different in the freelander install.

Fuel pressure regulator:
Your tests show a healthy pump output, but as the FPR housing is built into the fuel rail you can't actually see what's happening in the rail. One theory is your FPR is iffy, this certainly tallies with the possibility of low fuel under revs/load. An explanation of the FPR function is here Elise Parts - Road & Track - Performance - Power Boost Valve on this performence alternative. A standard FPR is >£30 so worth a go

Fuel contamination.
Whenever anyone talks of a misfire at low fuel there is a chance that there are nasties floating n the tank that only get sucked up when fuel is low. Drain the tank and fill with fresh fuel, also worth changing the fuel filter.

IACV
You have tested this and as its idling ok it's a long shot, but the IACV does have some part in on load running see here Idle Air Control Valve - TechWiki

ECU
I'm not that familier with the MEMS ECU. But it has some learning capability. Maybe it's got confused an needs a reset? There is a lot of rumour about how to do this, I'll try to find a reputable link. Also if you can do this with Diags make sure you know how to reset your immobiliser if fitted.

TPS
Unlikely as you tested it, does your diags show it at 0% and %100 against the max/min volts I think you can teach the ECU the TPS positions. It may be seeing part open when it's full open for example.

I'll have a think a bit more when I'm on a proper tinternet connection.

Im always glad for any info and hopefuly i dont come across ungreatful or anything like that but thought id let you know info on the Freelander version of the 1.8 K-series.....

Carbore said:

Looks like you tried a lot of stuff, iv still got a few ideas to add. All my k-series experiance is in my Elise, they are basically the same but sorry if anything is different in the freelander install.

Fuel pressure regulator:
Your tests show a healthy pump output, but as the FPR housing is built into the fuel rail you can't actually see what's happening in the rail. One theory is your FPR is iffy, this certainly tallies with the possibility of low fuel under revs/load. An explanation of the FPR function is here Elise Parts - Road & Track - Performance - Power Boost Valve on this performence alternative. A standard FPR is >£30 so worth a go

the freelander doesnt have a normal FPR on the fuel rail that return the excess fuel back to the tank like most cars ive worked on, the pressure valve is part of the fuel pump that opens after 3.5 bar and recirculates back to the tank or the start of the pump again, any fuel that leaves the pump at 3.5 bar should stay at the 3.5 till it reaches the fuel rail and injectors and never gets returned back to the tank, the only way is out the injectors and into the cylinders.... there is something that is at the end of the fuel rail that looks like a FPR valve but its actualy just a damper when the injectors open

Fuel contamination.
Whenever anyone talks of a misfire at low fuel there is a chance that there are nasties floating n the tank that only get sucked up when fuel is low. Drain the tank and fill with fresh fuel, also worth changing the fuel filter.

i did actualy think of this at the first time i started to sort the misfire out and i never drained the tank but did top up the 10ish litres in the tank with another fresh 20litres of petrol from the pump... that didnt help but since then ive added another 60litres of fresh fuel so if there was any crap in the tank it would have been realy diluted by now.... PLUS just incase there is something that didnt dilute into petrol, at one stage i had the fuel pump out to look at the seals on the fuel filter just incase it was leaking, and while it was out the fuel in the tank looked clean and i could see straight to the bottom with no discoloured layers

IACV
You have tested this and as its idling ok it's a long shot, but the IACV does have some part in on load running see here Idle Air Control Valve - TechWiki

i havent fully tested the IACV as im 99% sure its working and ive fully blocked it off and ran it just on the throttle slightly open and it doesnt make a diffence, so im not looking to much at this

ECU
I'm not that familier with the MEMS ECU. But it has some learning capability. Maybe it's got confused an needs a reset? There is a lot of rumour about how to do this, I'll try to find a reputable link. Also if you can do this with Diags make sure you know how to reset your immobiliser if fitted.

TPS
Unlikely as you tested it, does your diags show it at 0% and %100 against the max/min volts I think you can teach the ECU the TPS positions. It may be seeing part open when it's full open for example.

i took the TPS off and actualy used a screw driver to twist it while the throttle valve was still closed and the engine was ticking over and the ECU dumped more fuel in like it would need when the gas pedal is pressed sharply so there is enought fuel for the extra air entering the cylinders, and due to the extra fuel been added and no extra air it makes the engine nearly dye...... the values only go from 3.9 to 89.9 % throttle position, but the ecu learns where min and max are and no adjustmant is needed, and i can vouch for that, as just like you i thought the 3.9% wasnt minimum so i loosened the screws and tryed to rotate the TPS so it went to 0% but the only difference i made was it went to 11% and even set the hill decent control light off as it thought the pedal was always slightly pressed, but after afew ignition turn on/offs the ecus changed the 11% to 3.9% without even touching the TPS and the hill decent light went off..... so even tho it doesnt go from 0% to 100% im sure the values it does go to and from are the normal values, and as i get smooth increments im happy to say it doesnt loose signal when at a certian thottle postion when it starts to misfire
I'll have a think a bit more when I'm on a proper tinternet connection.

Click to expand...

REGARDS ADAM

Hello,

Its all a bit tricky this one.

FPR/Damper
I read up on the action of the FPR (Elise book) and both agree/disagree with your comments re Damper. The Elise book calls it a FPR but also says its just a diaphragm/spring thing so its not doing anything very clever. I did look a a picky of a Freelander k_Series on the net and I am sure that the FPR/Damper had 2 outputs (as well as being on the rail) so Im sure it DOES dump fuel. Interestingly some picture of standard replacement k-series FPR say damper so as far as I'm concerned the words are interchangeable. Somewhat regardless of the above, if the FPR/Damper is wonky then I wonder what the effect is, id imagine it creates a buffer so that if there is high demand for fuel equalises this. the fore if your FPR is wonky it won't? That said didn't you change fuel rails (including the damper/FRP) anyway?

Air Inlet Temp Sender (IAT)
You have not mentioned this. Elise book says its fitted into the inlet manifold tract of NO4 Cyl. Resistance reduces with increasing temp. Adjusts injector pulse for air temp/density in conjunction with MAP. Worth testing this if its open/short then could under fuel ?

Engine Coolant temp senders
Also worth a check?

Ill reply to your DM too.

UPDATE: Found my Freelander book

The FPR is called an Accumulator in the RAVE Book
As you say, The Accumulator is attached to the right hand end of the fuel rail. It acts as a damper to damp pulses from the pump to ensure that the fuel pressure to the injectors is constant. It is connected by a pipe to the inlet manifold from which it receives a vacuum to aid the damping process. Maybe this vacuum is not working?

sorry should have memtioned that my k-series is the euro 3 model which doesnt have the FPR valve and as youve just found out its just a damper. Ive put a second hand fuel rail on which came with the damper attached, and it didnt make it better or worse. So i dought its that whats causing the problem.

Also the later k-series doesnt have the IAT sensor in port 4, its blocked off with a bolt instead. The iat is part of map sensor, and when i unplugged it the air temp on the comp went to -7 degrees C and when it was running it was about 10 while the outside air was about 3 so looked ok as it sucks up some of the heat from the engine bay. I think i will test it again tho with a thermometer in the air track 2 see if it the same. To be honest stuff like that might make it fail the emmision but i dont think it would make it run as bad as this

regards
adam

Ok then...

Have you tested overall voltages. I read somewhere that stable voltage is an issue for the ECU. Let's say you have a bad battery, earth or more likely iffy alternator and the voltage breaks down or peeks during sudden revs, then all the sensor readings are out? (spark too possibly) You would need a good test kit for this as a basic digital multi meter might be to slow to see it, may even a scope?

Back ont he fuel damper, does the euro 3 engine not have a damper? If it does then as you have swapped out the damper already, could you test that manifold vacuum to abate my curiosity?

Hope this is helping.

you could have a point on the electrics i know how bad a crap earth can be to an ecu engine. I did notice an earth point at the back of the engine that looked as it was cut but couldnt find where they went. If you could look at yours and see where they go that would be great. There are 2 wires with crimps on the end that bolt 2 the back of the block roughly in the middle, undneith the inlet manifold. I could get a pic if you need 1?

Oh the battery is brand new aswell

yes euro3 has the fuel damper but no fuel return valve on the rail.

Vacuum on the inlet manifold is great, i did state in my first post. I got 20 inhg on tick over on my vacuum gauge and i think 16-21inhg is a good readin and shows theres no leaks, as long as it doesnt flicker as that shows it my have a sticky/burn valve. But my readings are good. I will test for leaks on the damper itself tho and report back.

Hope you can help with that earth aswell

regards
adam

I'll see what I can find re earths. I don't have a k series freelander though, it's my Elsie that's the k series and it's been modified to bits so not sue that will help. I'll look in my books. I'm traveling a lot tomorrow tho so won't be able to do much till Thursday, then into Christmas rush, so apologies if I "go dark" on the forum.

Eyup, got a similar sounding missfire on my 51 plate. As it happens i`ve had mine to local indie landy garage today.
I`ve got a slightly lumpy idle when cold, one pint of coolant used every two to three weeks, slightly down on power but NOT HGF, Excessive fuel consumption (18mpg).
The fault codes i have are P0303, missfire on cylinder 3, P1376, missfire recorded, P1232 fuel pump relay circuit fault and P0170 high fuel rail pressure (mechanical fault or low fuel pump pressure). All other parameters are as they should be according to the diagnostic machine.
P0170 and P1232 are probably down to a poor connection in the multi-plug between the harness and the fuel pump which i thought i`d fixed but it has come loose again.
P0303 and P1376 I have been advised are probably a leak in the inlet manifold gasket around number 3 cylinder which allows coolant into the bore when stood, hence the missfire when cold and rich running.
Beeen advised to reseal manifold and gasket to sort the problem.
Hope this helps.

disco-v8 said:

BUT since buying it, its always had a nasty misfire, either reving it in the driveway or out driving it and it can be easily repeated....
...first off it doesnt misfire when idling or reving slowly and i can rev it all the way to 6000rpm if im gental, but what ever speed im doing, any gear, any RPM, any engine temp, if i accelarate a little bit too hard (even in nautral) it will start missing and feels like power is starved as it feels like the brakes are slightly on

Click to expand...

So...did you fix it?

My MY02 Freelander had been suffering from the same symptoms - if you were very gentle, you could rev it all the way to the red line, but full throttle resulted in 2500~4000 rpm; almost as though a rev-limiter was at work.

One difference, was the fact that the symptoms had something of an intermittent nature, though they had reached the point where they were more often present than not.

This car had the mandatory HGF at 33216 miles and the new-style gasket and 'ladder frame' were fitted. There's currently no sign of water in the oil, or oil in the water - though there are a fair few oil leaks from various orrifices (cam carrier, sump etc). There is a very slight coolant loss and hints of an exhaust gasket leak. (Just what you'd expect really, from a car that only cost £20K and has done a whopping 69000 miles ;-)

The only fault logged was P0340 - Camshaft Position Sensor - though this has been present for the last 5 years. It's not the sensor, or the wiring, but presumably an ECU fault. It seems it's only used on this engine to set the sequential injection. Neither fuel efficiency nor performance seemed affected in the slightest by its absence. (BTW it takes 2~3 drive cycles before a fault code is set for the CMP - even if you disconnect it altogether).

The HDC amber light has been on for the last couple of years - coinciding with a change of accelerator cable (supposedly a known issue, so I've ignored it - more of this later!). On a least two occasions, the TC light flickered on, when applying full throttle (when stationary).

I changed the coils, leads and plugs and checked all the other sensors. I wired a second spark plug in series with no.s 3 + 4 plugs and noted that even when 'misfiring' there was still a spark (and a very healthy one, at that).

Attempts to measure compression failed miserably, due to the unfortunate purchase of a £10 tester off ebay (which was nothing like long enough to reach down the plug holes; at least, not without risking leaving bits of it behind). But in any case, the engine was healthy enough to start with either ignition coil disconnected - ie on 2 cylinders, so lack of compression was unlikely to be the cause.

A stethoscope on the injectors revealed them all clicking away merrily, and I managed to look at the ECU signals on my ancient oscilloscope. The oscilloscope wasn't up to the job of viewing the signals with the engine revs dancing around, but a cheap logic probe revealed that there were still pulses of some description present when 'misfiring'.

But in any case, if it could hit the red line on part throttle (no load), I couldn't think of anything fuel-system related that would explain why full-throttle would be so severely affected.

Which is when I started wondering about the HDC light and the flickering TC light....

I tried removing the ABS module fuse, out of idle curiousity - but it had no effect. But then, looking through the Haynes manual, I noticed a 'Throttle Pedal Position Sensor' - shown as a simple on/off switch. I'd previously read a description of MEMS 3, as fitted to Rovers - and they have no such switch (or input to the corresponding ECU pin). In fact, an adaption procedure is documented, in order for the ECU to learn the fully-closed and open positions.

Hunting around in the footwell, I located said switch - dangling on the end of its wire!!

In fact, mine is not a simple switch - it's a hall-effect sensor....there's also a spare connector in the loom that presumably was used with the simpler switch.

Anyway, with the switch back in its rightful place, the HDC light went off and the 'misfire' cleared!!

I think this hall-effect sensor has probably dangled loose for 2 years, before finally coming into semi-permanent contact with some metal object. The ECU then had a 'throttle-closed' signal, and a conflicting input from the TPS on the throttle body, resulting presumably, in some kind of limp-mode setting.

Of course, nothing in life is ever simple. In finally getting the switch to click properly into place, I managed to snap its electrical connector off
The HDC light has come back on, but so far, the mysterious misfire has gone.

(I did try to prove the theory, by placing a metal object on the sensor to simulate closed-throttle and then applying full-throttle. Sadly, I failed - so there's still some unexplained dark forces at work )

I read the title, I thought "unusual misfire for a K-series" - must mean it's actually running properly then

Phil you have given me new hope. My 1.8 missfires badly when cold and will hardly pull off. Once warm it's a rocket.I have replaced H.T coil,plug wires dist. rotor and plugs.Injectors have been sonically cleaned and tested O.K.Intake manifold checked for leaks and eventually a brand new head fitted. No water or oil usage and no faults on my BBS diagnostic so I hope your finding fixes my problem.

gruntygrant said:

My 1.8 missfires badly when cold and will hardly pull off. Once warm it's a rocket.

Click to expand...

Have you monitored the various sensor values (esp. Air / Water) using your diagnostic tester. If a sensor thought the vehicle was already warmed up when it wasn't, it might explain your symptoms? (I believe there's an Oil Temp. sensor as well - but my diagnostic tester couldn't see that; you'd have to use a voltmeter instead). I don't know what the ECU uses Oil temp. readings for.

If the heater circuit had failed on the front O2 sensor, that would have an impact too - though that should probably throw an actual fault code.

In my case, as well as the weird Accelerator pedal switch issue, it turned out that I had a second strange, intermittent problem: the pre-cat. in the exhaust manifold had detached itself and was revolving in the manifold! This didn't give a misfire, just a sudden, massive loss of power, when it revolved into a position that blocked the exhaust.

What I learned from the experience, was the Diagnostic Tester's ability to show you fault codes was actually its least useful function. The ability to watch individual sensors (and see the outcome of the ECU's own diagnostics) were much more useful. At the very least, it told me which bits weren't broken!

Unusual misfire on a k series freelander?

That's just another way of saying that the engine is running as it was designed to

strange_days said:

Unusual misfire on a k series freelander?

That's just another way of saying that the engine is running as it was designed to

Click to expand...

what the #### do you know about it..............jeep boy

Freelaner said:

what the #### do you know about it..............jeep boy

Click to expand...

Oh dear, once again resorting to name calling and dummy spitting. Get yourself a proper motor mate