Drive by wire throtlle tuning?

**MickG** · 28th March 2007, 01:34 PM

Okay, some of you may have heard me rant about this before in various related threads but I have a simple question (with some back groud info) which will help me understand what can and can't be done to my car

The Car
'99 Manual TD5 D2 with 156K on it, 4.11 diff gears, 33" mud tyres, Bruce Davis remapped ECU, straight through factory exhaust (muffler and resonator removed) New MAF sensor, throttle sensor, EGR valve, crank angle sensor, clean air & fuel filters etc etc.

The Problem
To get my car to move off from stand still I very often have to slip the clutch to get the thing moving and on hills, this is near impossible without the occasional stall. It seems the throttle when pushed does not want to rev the engine freely and when lifting off the clutch, the car just seems to die and bog down no matter how hard I then press the accelerator. I am aware of turbo lag but it feels like when the chip was reprogrammed all the torque etc was stolen from down low and thrown at the top of the rev range so nothing down low and then full on up top - but not that crash hot if you know what I mean - a lot of noise but not much go. There was one week a few years ago when it was first fitted when it went like a rocket ship and drove superbly.......but sadly that was for one week then start of problems.

The Research
At the weekend I was lucky enough to drive another '99 manual TD5 D2 with a standard ECU and this pulled so much better than mine and the throttle response was instantanious - also was not too far off the performance of my chipped D2

I also drive a standard (zero mods) 2004 TD5 Defender 90 occasionally and this also drives much better than mine with zero fuss and complete throttle response and control - often no accelerator needed to pull from lights or off from small hills and will out perform my chipped D2

The Question
Can my throttle response/mapping/timing/what ever you want to call it, be reprogrammed at all either through the ECU itself or by some other means? It is since I have had my ECU remapped that my problams have arisen and the ECU has been replaced and checked 2-3 times by BD himself each time resulting in no difference to performance.

I JUST WANT SOME LOW DOWN SMOOTH TORQUE/POWER DELIVERY TO PULL AWAY FROM THE LIGHTS WITHOUT STALLING

Any and all comments/input appreciated, Mick

**Phoenix** · 28th March 2007, 02:01 PM

Sounds like a problem with the ECU mapping to me.

Ruslan · 28th March 2007, 02:01 PM

Read somewhere don't remember now... possibly something to do with Anti-Stall programm in ECU.

What's happen if you do ignition start, I mean put on gear and turn key without touching accelerator?

**MickG** · 28th March 2007, 02:23 PM

Originally Posted by Ruslan

What's happen if you do ignition start, I mean put on gear and turn key without touching accelerator?

Car lurches forward and would start and keep going, so, would do what you would expect.

**discowhite** · 28th March 2007, 03:02 PM

sounds like one of them famous BD chip upgrades!

there was an update on the throttle sensor, something like one was a 2 wire and the other was a 3 wire witch was supposed to address the surging fault...(any time now scouse can chime in)

but ide look at borrowing a test ecu(std) and see if your problem dissapears.. bet it dose.

The Question
Can my throttle response/mapping/timing/what ever you want to call it, be reprogrammed at all either through the ECU itself or by some other means? It is since I have had my ECU remapped that my problams have arisen and the ECU has been replaced and checked 2-3 times by BD himself each time resulting in no difference to performance.

hopefully tombraider will answer this one.

cheers phil

**stevo** · 28th March 2007, 04:49 PM

is there a switch on the clutch pedal like the TD5 defenders?? I think a couple of people on here have disconnected their ones with better results

**dmdigital** · 28th March 2007, 05:25 PM

Originally Posted by discowhite

sounds like one of them famous BD chip upgrades!

there was an update on the throttle sensor, something like one was a 2 wire and the other was a 3 wire witch was supposed to address the surging fault...(any time now scouse can chime in)

but ide look at borrowing a test ecu(std) and see if your problem dissapears.. bet it dose.

hopefully tombraider will answer this one.

cheers phil

This is from Rovacom's help file:

Throttle 1 volts: This shows the output voltage from driver throttle pedal potentiometer 1 as read by the TD5 ECU. The voltage reading increases as the throttle pedal is depressed. A fault will be recorded if the sum of the voltages of throttle 1 and throttle 2 do not add up to the throttle supply voltage + or - 10%
Throttle 2 volts: This shows the output voltage from driver throttle pedal potentiometer 2 as read by the TD5 ECU. The voltage reading decreases as the throttle pedal is depressed. A fault will be recorded if the sum of the voltages of throttle 1 and throttle 2 do not add up to the throttle supply voltage + or - 10%
Throttle 3 volts: This shows the output voltage from driver throttle pedal potentiometer 3 as read by the TD5 ECU. The 3 Track Throttle Potentiometer configuration is not used on all vehicles and was introduced at VIN Number YA288371 on a Discovery and 1A605426 on a Defender. The selection may be configured in the settings section.
Throttle supply volts: This shows the regulated supply voltage for the driver throttle pedal potentiometers. The sum of the voltages from driver throttle pots 1 and 2 at any throttle position must add up to within 10% of this voltage or a fault will be recorded.

Pot: The TD5 ECU has been designed to work with a wide range of possible fitments and options. Many of the input sensors and output controls can be omitted giving many vehicle option, model or market variants. This value indicates if this TD5 ECU has been programmed to use a 3 track or 2 track throttle potentiometer. The three track configuration was only introduced after VIN number YA288371 in the Discovery series II and 1A605426 in the Defender. Failure to set this value correctly may result in the ECU being unable to see the application of the accelerator pedal.

**Graeme** · 28th March 2007, 05:45 PM

Has another MAP sensor been tried? They can get damaged by excessive boost whereby they become insensitive to lower pressures.

I've got much the same problem with my upgraded 2003 D2. It had the problem rather badly when standard and its improved somewhat with the ecu upgrade but its still a problem. Try taking off uphill from lights - lots of tries, eventually lots of revs and clutch slipping. I'd hate to have to do it with a 2 tonne trailer in tow.

I tried another MAP sensor after no change was felt with a new MAF. The new MAP sensor seemed to make a vast improvement initially but then the improvement dissapeared. I retried the old MAP sensor and couldn't pick any difference, but re-installed the new sensor anyway. I'm suspicious of my MAF even though it was replaced.

Please post if you get it fixed - I'm very interested.

**MickG** · 28th March 2007, 05:47 PM

Originally Posted by dm_td5

This is from Rovacom's help file:

Well mine is definitely the earlier ECU but going by what Rovercom say I would suggest that the throttle programming is where my problem lies........which is what I have thought for some time. There is no reason IMO why a modern TD5 engine with a remapped ECU should have such little low down torque that it stalls when pulling away

I know Tombraider has been working on the earlier TD5 ECUs and man am I hanging out for the results

Appreciate all the input and will report back as i go.

**dmdigital** · 28th March 2007, 06:10 PM

Let's hope Tombraider can add to this thread. It does sound like an incorrect throttle map's been used but I'm very new to all this map file stuff.

I suppose you could just think of it as really bad Turbo Lag until you get it fixed

Thread: Drive by wire throtlle tuning?

Thread Tools

Drive by wire throttle tuning?

Bookmarks

Bookmarks

Posting Permissions