Thread: D2 V8 economy pain

So now that the plugs must be in and the new leads as well, is the economy better?

So now that the plugs must be in and the new leads as well, is the economy better?

After plugs and leads, the misfiring stopped.

The fault codes still occurred (P0171 and P0174).

I bought a Intermotor afm sensor and since then the P0171 and P0174 fault codes have stopped coming up (so far).

The idling temp seems to stop at 98 for a while but still eventually reaches 102 degrees (which is what it was doing before any of this. I guess this is normal, and although I read a post here where a faulty afm was causing temp increases, there seems to be no correlation in my case.

Afer fitting the new afm, I took the car on a 38km loop from Ashfield to the M5 in Padstow and back in free-flowing traffic and on the ScanGauge consumption dropped pretty quickly to around 14.5L/100km. This is not bad and I think on a highway run it'd drop into the 13s, which is about as good as you'd expect in a D2 V8 (although I fluked 12.8L/100km Canberra-Sydney in my previous D2 V8 auto once, but it must've been with a tailwind).

I have had a few people tell me that non-Bosch afms are rubbish, but for now I am going to wait and see what this one does. Certainly cruising economy is on the money and fault codes are not coming up when they would before. I think there might be a slight hesitation at low revs that was not there before, but can't say with certainty.

Trip meter and refill calculations tend to correlate with the Scangauge results.

However I did get a 14L/100km figure cruising on the M4 before any of this, and I can't tell if performance is any better, so I really don't know if what I did was just preventative maintenance. The problem is that I don't have time to drive the D2 much and when I do find an excuse to drive it, it is usually to run errands over short distances - and maybe that's why it was averaging 25L/100km. I need to give it a good shakedown run.

Anyway, my new leather ES steering wheel has arrived from the US and a it made me feel so much better about my D2's economy

Ahhhhh the new leather steering wheel eases the burden somewhat.

Dont be too hard on the fuel consumption your getting. I get 15L/100k on a run/camp/4WD/run home trip and last week 23.5L/100k for a mixture of short runs, medium runs, school pick ups (less than 1k, I wonder where my wife left her legs!) and w/end trips to local Bunnings etc. All driven all without flooring the big fat GO pedal.

Worst ever was 30L/100k.

Hey, when we V8 drivers have finished with the worlds oil reserves, does that mean War everywhere will stop. Think about it

also means all those noisey smelly rattlers will stop

SNAKES !
what have they got to do with it?

4X4,
the occasional miss is the interesting thing. I have just replaced the coils for both V8 banks along with new leads & platinum plugs. Car averages between 14 & 15 litres/100kms & is a pleasure to drive. Alos, it has a Bruce Davis ECU chip mod. Car has plenty of torque & the cost of the chip was worth it. The cost of the coil replacement was aound $0.9k as a result of the plennum having to removed to get to them.

My ECU has started logging P0171 recently and more recently P1171 and P1174 codes as well.

I got the adaptations reset, and the engine stalled. When I started up the engine again, it idled roughly, like it wasn't running properly, which was quite surprising because this meant that the ECU had been compensating for some issue.

I've been told that if Bank 1 (passenger side in Australia) runs lean, it's often the case that the MAF has failed.

MAF was replaced with a known good one and the engine was good. Refitted my MAF and engine started running rough again. So it was a new MAF for me that fixed my problem. (How ironic that I posted this very thing on this thread not too long ago!)

I think all Disco MAFs are rubbish. I have replaced the original in mine three times in 90,000 km, and I am getting sick of doing so. They are just not of merchantable quality. My experience was that the fuel flow increased substantially, in part because you need so much more accelerator to get normal performance. In my case I notice that with a dead MAF the vehicle stays in third until around 80, whereas with a working one it normally changes into top at around 60.

Some of the fuel flows mentioned seem very high to me. Even with the 4.6 I still get around 13 LHK on a trip at 100-110, and around 17-18 in town. Towing a 2.5 tonne dirt road van I get around 26 LHK, but it varies a lot with wind direction and speed due to the van's dreadful aerodynamics.

4X4 V8, I never thought I would see someone put "economy" in the same sentence as "Disco V8". Good to see it is running better now.