Hi forum,

I've recently come into ownership of a 55 Fiesta 1.4 Tdci, which has just come back from its service.

The mechanic asked me 'what sort of electronics you have under the hood because it seriously is looking ratty'.

He proceeded to pop the hood on my car and pull out the item in the photos.

He showed me that, if he bent the cable whilst the engine was running, the engine would rock wildy and even cut out.

Both of stood there laughing because neither of us have a clue what it is! There is certainly nothing written on it so I am hoping that some more in-the-know types on the board might be able to ID it.

It's pretty clear that a former owner has tried to mod this car as there the remains of a Jap lighting mod are left in the car (that's the thing you can see drawing power with the fuse on it in one of the pics).

Massive thanks to anyone who can tell me wtf this thing is! It looks like a serial cable (?) that plugs into it, but the other end disappears off to the engine and out of sight.

Thanks

Edited February 16, 201313 yr by Stoney871
Swearing removed please don not swear on the forums

Looks like a tuning box to me

Yeh I'd say its a tuning box to it will plug onto the fuel rail sensor which is why the car will run ruff and cut out

It certainly looks like it's been bounced around a bit too.

I believe there should also be a sealing plug for the exposed port too.

Thanks.

I think it is one of these: http://www.tdi-tuning.co.uk/car_and_van_diesel_tuning_boxes/ford/fiesta/14_tdci_67_bhp__68_ps__50_kw/crtd_diesel_tuning_box_ford_fiesta_14_tdci_67_bhp_68_ps_50_kw_P318.html

Thanks to the nice cheesy man in the tight Polo shirt in the video at the end, I think I know what I need to do to lose the magic box.

Once you unplug it it should return to stock power and run as stock no problem

Thanks guys [and apologies to the Mod for the language ;-) ]

I unplugged the box from the port before starting the engine (I left the cable plugged in) and the car started/runs ok but comes up with an Engine Warning Light.

I looked deeper into the engine and it looks like the cable splits into two before going in two different directions.

On the basis of that description would you speculate that unplugging it from the ports would mean that the car returns to stock, or can it not live without the magic box anymore?

I would imagine that it would run ok without the "magic" tuning box, but sometimes people modify their cars and often it is wise to leave well alone, but you can try it with/ without to see what difference it makes

the lead splits in two to connect to the maf and the ECU, if you disconnect it you must reconnect the maf to the ECU

You may have to reset your ECU to recalibrate your ECU/ sensors, (to a change- adding / eg- removing tuning box) you do this by disconnecting the battery for half an hour, (or disconnecting the correct fuse) watch you don't loose your radio code

The dial on the tuning box is to turn it up/ down - the connector looks like a mini - USB connector to connect it to a computer, this may be for the manufacturers to program it for different cars or for different maps, it is probably digital

if you take it off you may find the car "gutless" because these things can often add 30+ Hp/ torques

Tuning boxes have had a lot of bad press - i used one for years - RRP - £400 not a £7 ebay "resistor box" - you get what you pay for (hopefully)

i needed Superchips (the leading/ longest established remappers in the world) to do 2 revised maps (remaps) to match the pickup/ bottom end grunt of the tuning box

I thought they connected to the common fuel rail pressure sensor and worked by overfeuling the engine not putting more air in

I thought they connected to the common fuel rail pressure sensor and worked by overfeuling the engine not putting more air in

They can sometimes connect to the common rail pressure sensor, and modifies the signal so it appears to be a lower pressure than it actually is, the ECU compensates by raising the fuel pressure to a higher level than stock

Often, instead of this a tuning box connects between the MAF (Mass Air Flow) sensor and the ECU, the signal is modified so the ECU "thinks" there is more airflow than there is, the ECU compensates by squirting in more fuel

Tuning boxes can sometimes be connected to BOTH the common rail fuel pressure sensor AND the MAF, or betwwen the ECU and the rotary fuel pump on a TDDI

Tuning boxes may be simple/ cheap resistors, or sophisticated digital microprocessors with multiple maps, ether way they need to be carefully set up/ calibrated and best to get one specifically built or set up for your engine/ car

Some also connect to the turbo actuator for direct control of the boost pressure

Looks like a fleabay special to me. The wheel for choosing the map looks cheap, and the hole for the PC connector isn't even cut to fit the plug, it's just a circle so absolutely no waterproofing whatsoever, you can even see the board...

Get rid of it... They are bad news!!

They do exactl what FOCA says and it's never good in the end lol

Light a fire in your back yard,

Get it burning around 1200 degree's

Then remove the tuning box and throw it in the centre of the fire.

Job done,

Ok chaps, an update on this one.

Took the battery out and found the connector to the Pressure Sensor and red plug. Removed both.

Tried to plug the Red plug directly into the pressure sensor (as I assume it used to be) but the plug doesn't fit?

I am meant to plug the red plug in directly and that is where it originally came from isn't it?

Or can anyone out there confirm a suspicion that not only is the Tuning Box an aftermarket part, but maybe some of these things come with a replacement Sensor with a slightly different plug?

The car is currently stuck in Limp mode :(

Ok chaps, an update on this one.

Took the battery out and found the connector to the Pressure Sensor and red plug. Removed both.

Tried to plug the Red plug directly into the pressure sensor (as I assume it used to be) but the plug doesn't fit?

I am meant to plug the red plug in directly and that is where it originally came from isn't it?

Or can anyone out there confirm a suspicion that not only is the Tuning Box an aftermarket part, but maybe some of these things come with a replacement Sensor with a slightly different plug?

The car is currently stuck in Limp mode :(

I remember reading that some of the rover ron tuning boxes came with replacement (upgraded) MAF sensors, but that was for Rovers, (they make tuning boxes for Fords too, but not sure about different maf sensors)

If you are not 100% sure what it is/ does, it may be better to leave it well alone, connected the way it was, untill you can find out

If it needs to stay on (due to modified connections etc) you may be able to turn it down a bit, sometimes you can turn these things down to stock or even lower than stock, again, best to find out what it is/ how it works

I think we need to see some more pictures If you could take the cover off it and post up some pictures of the insides :)

Forgot to post the conclusion to this one.

So, it was a fleabay tuning box.

Whoever fitted it also fitted a custom fuel rail plug.

I took it to a decent non-dealer I know who got it up on the ramps and confirmed it.

He then rang around Ford and found that they don't do the plug on its own?

Thankfully he recognised that it is a DV4 block so was able to source the plug from Peugeot.

Fitted it, sorted.

Thought I'd put the answer up as I don't think its terribly common knowledge that Peugeot do a fuel rail sensor plug that fits the Fiesta.

Would make sense, seeing the TDCi 1.6 is also the 1.6 HDi in the Pug, and the same for the Citroen :P