Running rich?

Ah, Lucas 14 CUX, this I know a bit about...


1) Temp WILL upset fuelling, BADLY on these non Lambda controllled versions in Oz.

2)Thermostat must be minimum of 88deg, and must be working quickly.

3)Back to the old throttle pot adjustment again, must read 300mV +/-20mV, as close to 320 as humanly possible at idle, or the ECU thinks the demand for more fuel is there, and increases fuelling via injector pulse width.

4)There must be no vacuum leaks.

5) The cam and valves must be in reasonably serviceable condition.(!)

6)The coolant temp sensor is not the same as the temp guage sender.

7)The fuel temp sender may at fault, but unlikely as its default setting will only make it harder to start in really hot weather, won't effect at any other point.

8)Tune select resistor, located taped to ECU loom with blue two pin plug, must not be open circuited.

9)The ignition timing is retarded? Try running it at 9 deg BTDC.

10) The AFM could indeed be at fault, only easy way is to substitute with a known working example and try it.

Just for interests sake,My money is on the thermostat, and/ or the ignition timing.

JC

Oh, and the worn out cam and valve seats leaking is a close second.

JC

My D1 takes FOREVER to heat up,,
(compared to the D2)
When my MAF went it would only run properly at full throttle(:D)
and you can imagine how the fuel guage responded

Has it been replaced before Quiggers?

Fit a new thermostat asap Oh Swift one. It may pay for itself in 12 months...
I also found the genuine ones are best, and use a genuine tin /coated gasket. easier to fit.

JC

Quote:

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Originally Posted by justinc

Fit a new thermostat asap Oh Swift one. It may pay for itself in 12 months...
I also found the genuine ones are best, and use a genuine tin /coated gasket. easier to fit.

JC

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'tis the reason I havent done it---
again.

Hey Scouse! do you do Paypal?:D:D

Quiggers,
The sensor which informs the ECU of the engine temp is located on the front drivers side of the manifold, facing upward and has an injection type plug.
Often it is just dirty contacts on the connector which increases the resistance.
The sensor which controls the gauge is located on the front of the manifold next to the thermostat and has one wire.
To check your MAF, you can put a volt meter on the signal wire and rev the engine. If you get a change in voltage it is working OK. The end wire is a reference which is trimmed by the pot on the MAF. It should stay constant. By the way, dirty contacts on the MAF can also affect economy.
I do not think its your MAF.
Ideally a dyno session would tell whether you are actually running rich.
The more technical diagnostic solution is to get a wide band oxy sensor and controller, and see what the mixtures are doing. But they cost $600.
I am currently setting up a narrow band sensor $15 off Ebay, and a jaycar reader about $19.this will tell me if I ever get around 14.7 or over 14:1, as the sensor reads about 1 volt at 14:1 and nil at 15:1, and 0.55 at 14.7:1.
You can also read the oxy sensor just with a multimeter.
The most expensive part will be to get an exhaust place to fit a boss for the sensor.
I do not know what I do then!!! LOL
I have a Unichip , so theoretically it should be possible to tune the ECU to 14.7 on cruise, but who knows. I strongly suspect that when they dyno your car they trim full throttle only and the part throttle settings are left to fall out.
This is my 2007 project, to cheaply improve fuel economy.
Regards Philip A

Wow! This all sounds fascinating, think I'm going to print off some of your wonderful notes and go fishing (under the bonnet).

I actually think this motor is in good condition overall (despite the recent oil sludge problem which has now hopefully been sorted).

If I put the foot right into it, I get a cloud of smoke from the exhaust. It is NOT oil smoke (as in worn rings etc) as the smoke is not that colour -

The smoke is a medium flat grey colour and very slightly brown.

However, this Disco does idle for probably far too long - having read what I have above - and it does do lots of short hops - less than 3 kms.

So maybe there are a few reasons already.

Just done a 30 k run and it ran just fine. A nice donk.

The new plugs (put in yesterday) are hotter than the old ones.

Thanks guys!

Cheers, GQ