Thread: Update 4.6 road trip

Originally Posted by ballbag

Gotta be happy with that.

The 4L intake might be restrictive but fuel ratios should still be correct if running the 4L software I would think. Is that right?

Originally Posted by garrycol

The Thor 4.0 and 4.6 engines have the same inlet systems - my understanding is that it is just the programming of the ECUs is a little different.

Originally Posted by ballbag

Thought the MAF and its housing were different. Not the case?

The 4.6 MAF is different,
the 4.6 inlet piping is different,
the 4.6 airbox lid is different.
and the important detail is--
Ozscots works with a 4L ECM,,
but mine didnt.
and the ONLY way to find out is via your LTFT's
This engine management system is concerned with only ONE thing,, and its not that you're stuck in a creek or trying to pass a roadtrain,, its ONLY and again,, ONLY concern is the crap coming out of its exhaust..


In the D2a's the 4.6 tune is in the ECM,, but you'll need TESTBOOK to swap it over,, I thought there were a couple of members here that had it,, (certainly not used/held any longer at LR dealers).

I am also led to believe there is no such thing as a 4.6 Manual from the factory,,,
Hey Ozscott!!!

Hi mate. Yes that's a good point I hadn't thought of. All 4.6 V8's were into North America I thought.. So auto only. Which makes my wierd but working well homologation a bit different.

😈

Cheers!

Hi Guys.
I have a question for Ozscott.
I have also upgrade my Disco 2 2004 from 4l to 4.6. but i'm not having any luck with my fuel economy. The truck wasn't running when i got it. I replaced the old motor with a Disco 2 4L block with 4.6 crank/pistons. 4L inlet and heads. stage 1 cam, Genie headers. She runs on injected gas as well.
She runs smooth on both fuels. But!
she run really rich / over fueling. Just been on the Dino and only 79KW output.
Not to good. I was thinking ECU set for 4L not 4.6L. Sent of my ECU to Mark Adams in the UK to be re-mapped for the 4.6, I also got him to supply the larger AFM and filter lid to suit. Fitted all last week. A better response from the pedal and even a different note. but still over fueling.
The guys at the Dino said maybe the injectors??
Help from anyone. don't know were to look next.

Matt & Jo.

what are the overfueling symptoms?
LPG or just PULP?

HI. over fueling on both petrol and LPG.
Injectors are fine, new AFM, sports exhaust. i did remove the filter box and ran straight into the AFM. Idle was rough. was running high flow are filter. replaced back to standard and removed the snorkel intake. idle ok again.
Went for test run and the front drive shaft uni joint gave in. towed back home.
will have to wait until next week to fix.

To sort this out you need to gather some data.
1. Confirm vacuum reading ? idle value and is it steady - I know you built the engine but recheck here first.
2. Read long term fuel trim at idle and in cruise( after about 15 minutes)
3. Confirm idle and WOT values from the MAF in either volts or gm/sec. Snap throttle reading is OK or rev it out in first ? as long as you get several readings.
4. Confirm O2 sensors respond normally - high voltage on WOT( rich reaction) and low voltage at idle when you introduce extra air by removing a vacuum line.

Once you have this evidence, you can work it out.

Data can be gathered by plugging into OBD port to retrieve live data.
As an example I have attached an image of a data steam via OBD ? injector open time, RPM, O2 voltage, MAF in gm/sec and throttle position. We can confirm that all these sensors are returning good data because at frame 258-260 we have 12.3 ms injector open time at WOT, O2 voltage high at 0.96 ( full rich), nice MAF ramp with a max of 82gm/sec and Throttle position 75%.

To see how your ECU is calculating fuel we need to check it is receiving good data.Without it, the job is more difficult.
Try to get this info and you will be able to work it out for yourself.

This seems like the right spot--
Finally had the chance to do an actual honest to god PULP fuel run,, only took 3 years
142kays using 17.9 litres.
or
22mpg
or
12 Litres per 100
or
7.9 kays per litre

thats an increase(decrease?) from 14 litres per hundred with the 4L

Originally Posted by Pedro_The_Swift

This seems like the right spot--
Finally had the chance to do an actual honest to god PULP fuel run,, only took 3 years
142kays using 17.9 litres.
or
22mpg
or
12 Litres per 100
or
7.9 kays per litre

thats an increase(decrease?) from 14 litres per hundred with the 4L

That's very impressive, I'm not getting much better than that in the Td5, it must make all that tweaking worthwhile and pleasing. well done.