Offroad-Express

As the heading suggests, overfuelling something bad. Fouls new plugs in a day.

Zuk tank and pump in, should be pumping up to 43 psi (similar to the VL/VN pumps that are used as aftermarket options by others) which the fuel pressure reg should negate (stock pumping 30-35-ish?)

MAF sensor is good

ECU is good

Have done plugs, leads, rotor cap and rotor.

Next on the list:
New coil (and relocating it too)
New fuel pressure reg
Replacement stepper motor
New injectors

Anyone got any other ideas/opinion/options

Check the temp sensor and also that the plugs on the sensors havn't had any of the pins pull out of the back of them

O2 sensors gone tits up?

no o2 sensors, managed to get one without them horrid things

Tu's, will look at that.... just had a terrible little thought too, the fuel temp sensor and the coolant temp sensor have the same plug dont they, and are in reasonably close proximity to each other... and Ive had them both off at the same time before...... uh oh

xj wrote:no o2 sensors, managed to get one without them horrid things

Tu's, will look at that.... just had a terrible little thought too, the fuel temp sensor and the coolant temp sensor have the same plug dont they, and are in reasonably close proximity to each other... and Ive had them both off at the same time before...... uh oh

will bugger all effect, unplugged both of mine the other day and had little change, mine occasionally over fuels badly, then clears up and carries on, in process of getting rid of rover ecu ....... going to megasquirt ( finally)


pedro

relevant advise from here and elsewhere so far is to do both the following:

a) check the temp sensors
b) change out the fuel pressure reg.

Will see how we go from there. It'll be three weeks at least until I get back up to the truck, with 4 pretty little weld in beadlocks courtesy of Summit racing.

The radiator is going to the rear as well (= chassis cut at front etc etc... woohoo)

Have you measured the fuel pressure at the rail? One other component to check is the throttle position sensor. Definitely check coolant temp sensor though and make sure you havn't swapped the wires from the cts and the fts.

got the files, cheers for that Ian

This website has the resistance the various sensors should be at the different temperatures.

http://www.britishv8.org/Articles/Rover-14CUX-EFI.htm

You should be able to use a multimeter to check for a faulty coolant and fuel temp sensors.

Cheers,

Pete

This is the relevant info out of the link I posted:

"To troubleshoot the Throttle Position Sensor, first disconnect system power and then disconnect the EFI Cable Harness from the ECU. Using an Ohmmeter, verify that resistance between terminals 3 and 25 is between 4000 and 6000 Ohms. Next, reconnect the EFI Cable Harness to the ECU, and turn the ignition key switch "on". Take voltmeter readings from pin 20 to ground. With the sensor in the throttle-closed position, you should read 0.085 to 0.545 volts. With the sensor in the throttle-open position, you should read 4.2 to 4.9 volts. In between these extremes, turning the throttle position sensor should produce a smooth sweep of voltage readings."

and

"The Coolant Temperature Sensor should change resistance with heat, per the following specs.

-10C (14°F) 9100-9300 Ohms
0C (32°F) 5700-5900 Ohms
20C (68°F) 2400-2600 Ohms
40C (104°F) 1100-1300 Ohms
60C (140°F) 500-700 Ohms
80C (176°F) 300-400 Ohms
100C (212°F) 150-200 Ohms"

and

"As air flows through the MAF Sensor and specifically over its wire elements, inevitably some dirt accumulates. Although the mileage between cleanings seems to vary widely, the MAF Sensor will need to be cleaned occasionally. It's possible to buy "MAF Sensor Cleaner" in a spray can. Regular old "electrical contact and tuner cleaner" will work too. If cleaning as part of routine maintenance, disassembly of the sensor body isn't generally required."

I would look closely at the coolant temperature sensor as the ECU uses this sensor to richen the mixture significantly and apparently they are unreliable. Plus its an easy test, one at room temp, put it in the fridge/freezer, then boiling water.

Cheers,

Pete

Pete,

thanks for the info. Stuff Ive read about the "regular old electrical contact and tuner cleaner" though suggests that it shouldnt be used as it leaves a residue after drying than can affect the MAF.
I havent got the vehicle with me, but will certainly arm myself with some parts and a multimeter in a few weeks when Im in the North again and go through the scenarios.

Cheers

Mark

xj wrote:Zuk tank and pump in, should be pumping up to 43 psi (similar to the VL/VN pumps that are used as aftermarket options by others) which the fuel pressure reg should negate (stock pumping 30-35-ish?)

MAF sensor is good

ECU is good

Have done plugs, leads, rotor cap and rotor.

Next on the list:
New coil (and relocating it too)
New fuel pressure reg
Replacement stepper motor
New injectors

No worries, your probably rite about the MAF cleaner.

Just a note about the fuel pressure thing. The nominal fuel pressure for the disco is 2.5bar/36psi above the manifold pressure.

Good luck,

Pete

Fukkit, gunna give it a birthday:

as above:
New coil (and relocating it too)
New fuel pressure reg
Replacement stepper motor
New injectors

Plus:
coolant temp sensor
fuel temp sensor
throttle position sensor

Seems i'll be stopping by el rexos soon for him to relieve me of some $$

New adage "when in doubt, throw more money at it". I thought Jeeps were a PITA....

So did a sprint up north on Friday, changed out the below:
New coil
New fuel pressure reg
coolant temp sensor
fuel temp sensor
yet more plugs

..................... to no avail. TPS and Stepper were ruled out on some advise from some LR nuts. However, seems the advise I ignored may be the solution..... going to try another ECU. (yeah yeah I hear the "told ya so's")
When i tested mine against one know to be crook and one known to be good, it was only in the garage, idling. If there is an issue with mine, i guess its not showing until after running and driving it for a while, a replacement one will be worth a shot.

On another note, the beadlocks are on and a fairly EPIC