2003 K Series misfire Injectors or coil pack

Good morning all

Hope it’s not too early to pick your brains!

The car in question is a 2003 Freelander it’s a K series engine

A couple of weeks ago I noticed that the car smelt of petrol a few times when starting up. There was no problem starting and the car ran well. Yesterday I drove the car 30 miles and parked up all okay. Came to start the car and got the engine management light (flashing yellow) on plus misfire i.e. running on 3 cylinders. Got the vehicle home (recovered) and inspected this morning. Removing number 4 lead the engine runs better and engine management light goes out (not what I expected). Put a spare plug in the lead and it appears to be firing ok.

This sounds to me like number 4 injector fault. This is my reasoning this is coil pack type ignition (wasted spark) and if I’m right then 1 and 4 fire at the same time just that one or other has no fuel to ignite is that correct. But if the injector had failed and fuel was getting in it would fire 1 and 4 together cause "misfire " and emissions fault thus illuminating engine management light is my reasoning correct?

If not then what should I check?

Many Thanks Tannebri

It could be the coil or lead failing. The theory is it's harder for a spark to propagate when compression is appled so your plug could spark out the engine but might not in the engine. Whether fuel is injected or not the plug should still spark. When were the plugs last changed and were they platinum?

I have no idea when the plugs were changed but they are platinum. The leads look past there best so I'm changing them and plugs anyway.

How do injectors fail? do they pass fuel all the time or stick shut?

Tannebri

Tannebri said:

I have no idea when the plugs were changed but they are platinum. The leads look past there best so I'm changing them and plugs anyway.

How do injectors fail? do they pass fuel all the time or stick shut?

Tannebri

Click to expand...

You could do with the codes begin read to ascertain what put the light on in the first place.
Injectors normally fail electrically or clog up with dirt. I've never heard of or seen one pass fuel all the time but if one did it would fill the sump with fuel in no time!!

Okay

The fault codes are

P0480
P0420
P1300
P1316
P0301
P0300

Any help please as Coil pack, plugs and leads have not fixed.

Tannbri

Tannebri said:

Okay

The fault codes are

P0480
P0420
P1300
P1316
P0301
P0300

Any help please as Coil pack, plugs and leads have not fixed.

Tannbri

Click to expand...

P0480 http://www.bba-reman.com/content.aspx?content=DTC_P0480_WITH_AC
P0420 http://www.bba-reman.com/content.aspx?content=NEXT_DTC_P0420
P1300 http://forums.mg-rover.org/archive/index.php/t-250449.html
P1316
P0301 http://www.obd-codes.com/p0301
P0300 http://www.landyzone.co.uk/lz/f9/53-plate-freelander-obd2-compliant-58022.html

So you have multiple misfires on random cylinders p300
A misfire on cylinder 1 ( caused be running the engine with the lead removed?) p301
And a fueling error p420/p480
I'd be looking at fuel pressure regulator or fuel pump.
Or Has the timing belt jumped?

It's the coil pack!

My friendly mechanic was so convinced that it was the coil pack he took one off another car fitted it and away it went. Took the so called new coil back to the motor factor who exchanged it, fitted this one Purrfect. Now got to sort out the cooling fan fault.

Many Thanks for all your help

Tannebri

Good

Need some help please testing my coils on my 2.5 V6. \

Diag is saying misfire on cylinder 2.

I've got one of the coils out. Have set MM to 200 (in the ohms section) and with red lead on the left pin on the coil head, black lead on right most pin shows 00.8. Nothing on middle pin.

With MM on 20 v, red lead on left pin, and black on middle shows 0.24 and nothing on right pin.

I was expecting the second test to show something like 12.

Please could you tell me either a) if i'm doing it wrong or b) if this is confirmation of a dodgy coil pack?

Thanks

The coils should have a resistance of 0.8 to 1 ohm.
Just swap the coil with the next one along and see if the misfire moves to. If the misfire doesn't move, the coil is ok. The engine ECU monitors the resistance so would flag an open circuit. It can't monitor the plug or secondary windings though.

Nodge68 said:

The coils should have a resistance of 0.8 to 1 ohm.
Just swap the coil with the next one along and see if the misfire moves to. If the misfire doesn't move, the coil is ok. The engine ECU monitors the resistance so would flag an open circuit. It can't monitor the plug or secondary windings though.

Click to expand...

Thanks. It's in a few pieces at the moment so was hoping to test the coils without running the engine. So in the case of this coil, it sounds like the resistance on the outer pin is correct. Just not sure about the middle pin..?

I checked in RAVE and it only had useful info for the K1.8.

The rubber at the bottom has split a bit so basically hoping I can just replace that and save myself the £40 odd for a new coil! (Although need to find the rubber piece on its own.)

I figure I may as well test all of the coils whilst I'm at it.