Hi guys, still persevering with my money pit. '98 300TDi Disco Premium (ES) Auto. Looking to up the oomph. Please can anyone point me at a circuit diagram of the EDC unit (AMR 6228). I reckon if I can see that I ought to be able to figure out how to tweak it to up the fuelling. Might need to decipher the injector pump too, but that looks to be fairly straightforward.
Feck arse etc
Thanks Derek, unfortunately you missed the Auto, ALL Auto 300TDis are EDC so none of the mechanical pump solutions work. Hence my request for the circuit diagram. With a circuit diagram I stand a good chance of making my own 'chip'. As I understand it the EDC is most likely analog cicuitry, not a microprocessor in sight. Analog circuitry has the advantage it is understandable and for the most part linear. If no one has a circuit, anybody got an EDC I can dismember and divine the circuit?
No didnt miss it I think you may find not all , just the later Auto's have the ECU ( so I was advised anyway, tho not what year it was introduced. I have seen post 96,98 etc quoted but as I remarked the fly by wire is the clincher i.e. not having the cable) . A quick and dirty solution which gets berated is to tweak up the turbo pressure and put a variable resistance in the temp sender circuit which allows you to richen the mixture by reducing the sensor output persuading the ECU the engine is running colder and increases the fuelling- the famous ebay " boost by 15 HP" solution for £10 ( dear for a resistor) I can see there could be issues at low speeds tho'. What I do rate is using exhaust wrap to reduce the underbonnet temperature thus the charge is denser and you get a bit more power. I've done Kato and if it ever stops raining for long enough to complete the other work I will do Miles plus you dont toast your hands when fettling about round the manifolds and above all its cheap to do!
Derek Kato 200TDi Disco Miles 300TDi Disco
Hi Derek, I've been told it is ALL Autos and late manuals, but 'late' is undefined! I'm not so keen on tweaking the boost, I've heard disaster stories as a result of that. The object is to up the oomph and improve the mpg, or at least not impair it too much, not to blow a turbo and further excavate the money pit. I agree the £10 is exhorbitant for a resistor, but that does seem a neat way of fooling the EDC to up the fuelling. I had been wondering if upgrading the intercooler was going to be a complete waste of money if I couldn't adjust the fuel to match, I had realised the intake temp could possibly do the job but I'm grateful for the confirmation. I'd still like to look at the circuit to understand just what's going on, and might be able to come up with something else. I like the idea and price of lagging the exhaust. I can see that bubbling up the to-do list.
Lagging the exhaust will improve the spool up of the turbo alittle, and also help with underbonnet temps. Get a gauge on the turbo and make sure the wastegate hasnt gone soft, set it to 1bar with either a new diaphragm, or a bleed valve.
The biggest increase in both power, torque and mpg will be through a larger intercooler (especially the auto's as they spend alot more time on boost) as the factory one is marginal to say the least. Your headgasket will be under alot less strain that way also.
Then up the fuelling with preferably a re-map or a chip. The resistors don't work- the ECU only offsets fuelling by 5-8% depending on the air temp sensor, you need alot more fuelling, especially in the mid range than that, and also more timing advance too. A resistor cannot do that even a £20 one!
Bite the bullet and have it properly remapped with a larger intercooler. I can whole heartedly recommend these people:
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