Rough Idle/misfire on start up

[Epic_Dragon]

Hello folks :) seeking advice:D
My disco just in last 2 days has on start up, idled rough/ misfire for about 30 seconds then runs sweet. It has been really really cold and wet so not sure if just a slow glo plug? I am going to replace the injector harness and run an injector cleaner through.
Have checked oil for signs of diesel but all clear so don't think it's a failed copper washer?
I don't remember it ever in the 8.5 years I've owned it, have this on start up before, but I also don't remember ever having such cold and wet weather [emoji28]
The old girl gets hand controls fitted next month so need to ensure she's all ok. Also isn't getting run or driven much at the moment and had not been started for a couple of weeks before starting up 2 days ago and first having this rough start up. Then started up yesterday and the rough idle was even shorter (like 15 seconds) than the day before.

Thankyou in advance folks.
I've not checked the red plug for oil in some time but every time need to clean that I've have a consistent misfire and power loss.

[PhilipA]

Have checked oil for signs of diesel but all clear so don't think it's a failed copper washer?

The diesel in oil is generally caused by the Oring at the top of the injector failing.

Generally if the copper washer at the bottom fails it causes compression to force air into the fuel rail in the head and cause no start or rough running.

So probably your injector washers are crook.
I have never seen my glow plug light on and doubt whether they activate anywhere in Oz , although it can get damn cold in SA.
Regards PhilipA

[V8Ian]

Do you get the misfiring when starting it while warm?
Could be fuel running back.

[Epic_Dragon]

Ill see what happens when start it warm :)

Theres no diesel in the oil though at least

[Epic_Dragon]

I've ordered glow plugs. Haha why does it have 4 for 5 cylinders?
But it's fine to start after that initial cold start, even if car isn't warm yet :)

[V8Ian]

I doubt it's glow plugs. Could be as I previously suggested. What check valves are in the fuel system?
Can the FPR allow air into the system?
Leonie, have you had any small leak from the right side, back of the engine?

[Bohica]

The diesel in oil is generally caused by the Oring at the top of the injector failing.

Generally if the copper washer at the bottom fails it causes compression to force air into the fuel rail in the head and cause no start or rough running.

So probably your injector washers are crook.
I have never seen my glow plug light on and doubt whether they activate anywhere in Oz , although it can get damn cold in SA.
Regards PhilipA

Yes, -5C once in the snow, I did not see the glow plug light. Maybe I missed it.

[Epic_Dragon]

No fuel leaks :) had that leak in the other disco here before. Mine isn't though.
The old girl runs sweet after that first cold start. I have had a few weird starts before this rough 30 seconds or so that isn't battery or starter or anything. Can't explain it haha.

My glow plug light always comes on! It's been taking longer to go off recently. The glow plugs were not expensive though so is an easy thing which I'll feel happy its got fresh ones even if isn't the cause [emoji7]

[onebob]

The diesel in oil is generally caused by the Oring at the top of the injector failing.

Generally if the copper washer at the bottom fails it causes compression to force air into the fuel rail in the head and cause no start or rough running.

So probably your injector washers are crook.
I have never seen my glow plug light on and doubt whether they activate anywhere in Oz , although it can get damn cold in SA.
Regards PhilipA

Check that the relay is still there and/or still working - my glow plug lamp illuminates for all starts where the coolant temperature is below 20degC. The glow plugs are vital in the engine starting strategy with the ECM controllIng pre heat and post heat time. I have a replacement set of NGKs to go in after I modify the disintegrating push-on connectors….

[PhilipA]

Check that the relay is still there and/or still working - my glow plug lamp illuminates for all starts where the coolant temperature is below 20degC. The glow plugs are vital in the engine starting strategy with the ECM controllIng pre heat and post heat time. I have a replacement set of NGKs to go in after I modify the disintegrating push-on connectors….

I replaced mine about a year ago as I got strange resistance readings. I was able to repair the loom with large shrink wrap .

However I have never had any error codes and the car always starts on all 5 first cylinder usually, and never with white smoke. I have a Nanocom but the references on landyzone were for Lynx. I don't know whether Nanocom reads the 2 error codes that SierraFerry noted or not.

I will however check the fusible link and relay. Thanks for the heads up. My car has certainly been under 20C at times.
Regards PhilipA
The fault codes are
3070: Glowplug Lamp Drive Open load logged, and
3071: Glowplug Relay Drive Open load logged.

[PhilipA]

Bob, I have now tested the fusible links and the black relays which include R6 the glow plug relay and FL2 the glow plug fusible link. All are in fine condition. I tested using pos and neg to the trigger wires , listened for a click and also placed the ohm meter across the main input and output terminals. The ohm meter dropped to zero immediately. I tested the fusible link by just placing the ohm meter across the terminals and it read 0 ohms. In addition a visual check showed the link was intact.
I can only conjecture that when you thought the car was at 20C it actually was much colder maybe from overnight. Maybe your pre 2002 is different to the later engines.
Regards PhilipA

[V8Ian]

I doubt it's glow plugs. Could be as I previously suggested. What check valves are in the fuel system?
Can the FPR allow air into the system?
Leonie, have you had any small leak from the right side, back of the engine?
Any input on this theory?

[Epic_Dragon]

I have a new injector harness in the way and am going to check the red plug just incase. I wish I could upload a video in here! It didn't do the rough idle yesterday but had a weird revv briefly. I'll try do a YouTube one!

[Epic_Dragon]

27 July 2021 - YouTube (https://youtu.be/ONYN4l5CCLo)

[DJRC2450]

Hello folks :) seeking advice:D
My disco just in last 2 days has on start up, idled rough/ misfire for about 30 seconds then runs sweet. It has been really really cold and wet so not sure if just a slow glo plug? I am going to replace the injector harness and run an injector cleaner through.
Have checked oil for signs of diesel but all clear so don't think it's a failed copper washer?
I don't remember it ever in the 8.5 years I've owned it, have this on start up before, but I also don't remember ever having such cold and wet weather [emoji28]
The old girl gets hand controls fitted next month so need to ensure she's all ok. Also isn't getting run or driven much at the moment and had not been started for a couple of weeks before starting up 2 days ago and first having this rough start up. Then started up yesterday and the rough idle was even shorter (like 15 seconds) than the day before.

Thankyou in advance folks.
I've not checked the red plug for oil in some time but every time need to clean that I've have a consistent misfire and power loss.


Hi
Mine used to do this and my issue was the fuel pump had given up, when you turn on the ignition, listen and make sure it's pumping
Dylan

[mylesaway]

Any input on this theory?

There is a air bleed (membrane type) in the fuel filter housing.

I don"t think this the issue but worth a Goggle anyway.

Replaced mine at 200,000Kms while looking for other issues.

Re glow plugs- I wait until the light goes out (5 secs) and then start. Gives the fuel pump time to prime up.

My D2 same yr etc as L's.

Cheers

[Epic_Dragon]

I've always waited for the glow plug light to go out before starting [emoji41]
I'll listen for the fuel pump!