1999 Land Rover Freelander 2.0XEDI "surging"

[solardb]

Hi, I brought a 1999 Land Rover Freelander 2.0XEDI, knowing it had mechanical issues.
The Engine misses at regular intervals on idle. Is not so much a miss , as more of a reverse surge. Most of the time it revs freely with no load on . However , when you try to drive it , it jerks and sputters form idle to about 1800rpm, between 1800 rpm and 2500 rpm it runs beautifully, about 2500 rpm it starts to miss again , but no where near as bad as below 1800rpm. It is baffling how it runs so well around the 2000-2500rpm range, which corresponds to 80- 100 km/h.
I have put a new air filter and fuel filter, to no great improvement. I also blanked off the egr valve , again no improvement.
i took it down a back road, and let it rev to 4000 rpm or so in 3rd gear, it didnt like it at all , and dropped to 60-70 kmh. When I got back there was a noise like a police siren coming from the engine , probably from the tutbo area. The next day the noise was gone.
Any ideas on what is wrong?

[woko]

There is another fuel screen in the banjo bolt on the inlet of the injector pump.

Noise could be a leaking manifold gasket. Intake and exhaust are the same gasket. The engine ecu will try to adjust for different readings between MAF and MAP sensors if leaking. Check for leaks.
The MAF and the coolant temp sensor can cause surging. Disconnect each individually and go for a drive. The radiator fans will run at full speed when the ECT senor is disconnected. Check wiring going to injector pump. It can chaff.

Do you have access to a Hawkeye or similar to read codes?

Sent from my GT-I9295 using AULRO mobile app

[solardb]

Thank you Woko. Should disconnecting the maf sensor bring the engine warning light on? It doesn't.
Where is the map sensor?
I will try disconnecting and driving later on today.
Having the codes read is probably the next step.i have a rennac scanner for my prius , I will see if it can be registered for landrover.

[woko]

Disconnecting the MAF won't bring on the engine light. The MAP is mounted on the fire wall behind the air filter. There are 2 there. One is Map the other is for egr The one on the drivers side is map. The one on the pass side Egr

Sent from my GT-I9295 using AULRO mobile app

[solardb]

Thanks. Haven't had a chance to get back to it yet.

[solardb]

Progress !
Disconnected the temp sensor, as you said the fans come on full bore.( well they sort of ramped up , but were full bore within a minute).
Disconnected the maf sensor wires. It idles smoothly.
Took it for a drive, massive improvement. There is now only a single miss around 1500rpm under load. above 2500 rpm there is still a miss , maybe just a single one but it repeats occasionally. Its now actually driveable.
I see I havent followed your instructions and tried them individually, I will try that now.

[solardb]

The Temp sensor has the most effect. With that disconnected, it runs reasonably well, a miss around 1500 rpm , and another around 2700-3000 rpm.
I have reconnected the maf sensor and it seems to make little difference to both been disconnected.

does this mean the temp sensor is faulty, or is it the circuit it is feeding into ?.

[woko]

If it makes a difference for the better it will be the sensor. I have replaced a few of these. The part number is ERR2081

[solardb]

thanks , have ordered one off Ebay.

[solardb]

Sensor has arrived. It measures 3.5 Kiloohms resistance on a NZ winter morning , probably about 10 degrees celcuis. Putting it in a cup of boiling water, the resistance reduces to around 0.5 Kiloohms, or 500 ohms. I would say it is a 5 kiloohm NTC thermistor.
Might be helpful for anyone wanting to check their sensor.

[solardb]

Another question, our local supplier sent 2 fuel filters to replace on the freelander. One had the pipes out the top , obvious;y a replacement for the one ny the passenger wheel arch . The other is a spin on one, similar to a oil filter.
Is there another fuel filter, or was he just covering the options for different models?part number is fram p 9444

[woko]

The early TD4 has a screw on type fuel filter.
There is only one fuel filter.

Sent from my GT-I9295 using AULRO mobile app

[solardb]

Hi , finally got this freelander scanned, came up with no codes of any problems.Frustrating.
The auto electrican noticed the boat type fuel pumper before the fuel filter, and commented that this did not look standard. (black bulb that you squeeze to pump fuel through . He thought this indicated it has been having fuel problems for a while.
Is this a standard fitting?
I was wondering if I added a electric fuel pump in place of the boat bulb type , would this eliminate fuel delivery as a problem. We cleaned the tank out , there was black sludge in the plastic cannister where the fuel take off pipe sucks through it. by the orange / red neoprene seal.

[woko]

That primer is standard. There is a small screen in the banjo bolt on the supply
To the injector pump. Pull it out and clean. With sludge in tank alge is in the diesel. You will need to put a treatment in it to get rid of it
Sent from my GT-I9295 using AULRO mobile app

[solardb]

Thanks, have put in a injector cleaner and biocide. We drained the tank completely and put fresh fuel in.
another question.
Directly above the fuel filter is a small box with 2 brown wires going into it .
It appears to have a button under the black rubber top that you can push . nothing seems to happen when you push it ?
What is this box and should it have more wires or pipes running to it ?

[schuy1]

That 'small box' is the inertia switch. When you hit something large and solid it turns off the feul pump, engine and starts the hazards. If at any time the car appears dead push it just to be sure that speed bump you didnt see at the shopping center did not jar it off