Well, I never would have believed it would come to this. Hippo was fitted with a Tunit box when I bought the car. Their kit is listed here

Diesel Tuning by Tunit Diesel Performance With Over 2500 Applications

This box, which is the size of a match box, with a 9 pin 'D' type connector at one end, is listed for £422 pounds. For all that money, the power output is raised from 97bhp to 120bhp and the torque goes up from 156 foot/pounds to 181 foot/pounds.

The car goes well, but it was clear to me that others on here were getting 500 old miles to the gut full of dozel, where as I am only getting 400, if I'm lucky.

Now that its costing me £70 quid to fill the tank, steps had to be taken.

So I've unplugged the box. I left the loom that came with it that is spliced into the ECU. It seems its quite simple. No box = 97bhp, fit box = 120bhp. Its that simple that the difference is astonding. It makes it a different car, without it it drives like a lorry. On the plus side the engine is quieter and a lot smoother to drive in lower power mode.

I took the car out on the dual carriageway and was dissapointed that I was being passed by virtually everything. Plug the box in and it jumps light speed and its me doing the overtaking. However, with the normal trundle to work and back I don't need this performance, so the box is unplugged. Got to be done to save some fuel.

I don't have any of the paperwork with this box. Analysis of the wire loom shows that there are four wires. Two are power and ground, the other two are spliced into the two of the several connections between the ECU and the fuel pump. It doesn't obviously seem to be playing with the engine temperature as I was led to believe. Hanyes doesn't identify the function of the two wires so I can't say what this box is actually doing. Whatever, it does works, that I can say.

I wish! i'm only getting ain the low 300's on a tank.

Something wrong somewhere

i reckon i could get 0 mpg on a gallon of fuel for that...

When i fitted my go faster Gizmo [carnt remember its name] it improved the mpg. . . . . .carnt you make it switchable ?

Thought about that Ming. The thing is I don't know what would happen if the unit was connected or disconnected when the engine is running. If it would allow that then a simple switch and a relay would be employed.

I'll see how it goes but I see it this way. To get more power required more fuel burn per second. Unless the 'chip' is modifying the fuel mapping then I can't see how it could save fuel. Lets see what happens next time I have to take Hippo to the watering hole.

try rigging up a switch in the power ;line - see what that does?

Beast o Bodmin said:

i reckon i could get 0 mpg on a gallon of fuel for that...

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I wonder how many of those 10,000 odd posts you've made just say 'Burn it'? I'm sure a simple script to search and delete those posts would save so much disk space on the server. Tis getting a bit boring now Bob.....

pardec said:

I wish! i'm only getting ain the low 300's on a tank.

Something wrong somewhere

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Ere, check your injector bleed off pipes aren't leaking. It looses loads if they are....

Was out at the weekend. Went out in the sticks with daughter and in-laws for a walk and a bit of fresh air. When it was time to come home I pulled out on the main road straight onto and up a hill. About half a mile down hill was a lorry hoofing his way up. I pulled out, floored it and shifted through the box. By the time I got to the top said lorry was on the verge of pushing me.

Wouldn't have happened with the box fitted!!

We stopped again on route at a pub. Before leaving there I fitted said box.

"Watch this then!!"

There were three green faces after that as me and Hippo had some fun.

Darmain said:

Ere, check your injector bleed off pipes aren't leaking. It looses loads if they are....

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Had a fuel leak just before christmas. Think it was the return pipe from the injectors,Landranger in stockport did the job.

Wha else could be causing low mpg?

pardec said:

Had a fuel leak just before christmas. Think it was the return pipe from the injectors,Landranger in stockport did the job.



Wha else could be causing low mpg?

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Well, if your engine is over fueling then there would be black smoke evident from the exhaust. For a guide, mine only smokes for a few seconds during cold start up and no more. If you have a diesel leak then you will smell it. Diesel doesn't vapour off as badly as petrol so you will find the leak as well.

If you're handy with the spanners then take the engine cover off (if you have one, I took mine off to the help air flow round the engine) and look for anything that is wet. Basically it shouldn't be. The little flexible inter injector pipes are the bleed off pipes that take excess fuel back to the fuel take via the fuel cooler. These little beggers perish and leak for a past time. All these pipes should be dry. If not then replace them (Don't muck about with them to make them stop leaking, it ain't worth it). Thay can easily be taken off and replaced by cutting new lenghts of pipe to suit. You can get this pipe in most auto factors, even Halfords if your desperate. When complete you will need to reprime the fuel system by giving several squeezes of the fuel bulb up in the back corner behind the battery.

Other things to try are to replace the air filter and run some injector cleaner through the system.

Report on how you get on and good luck.

Darmain said:

Well, if your engine is over fueling then there would be black smoke evident from the exhaust. For a guide, mine only smokes for a few seconds during cold start up and no more. If you have a diesel leak then you will smell it. Diesel doesn't vapour off as badly as petrol so you will find the leak as well.

If you're handy with the spanners then take the engine cover off (if you have one, I took mine off to the help air flow round the engine) and look for anything that is wet. Basically it shouldn't be. The little flexible inter injector pipes are the bleed off pipes that take excess fuel back to the fuel take via the fuel cooler. These little beggers perish and leak for a past time. All these pipes should be dry. If not then replace them (Don't muck about with them to make them stop leaking, it ain't worth it). Thay can easily be taken off and replaced by cutting new lenghts of pipe to suit. You can get this pipe in most auto factors, even Halfords if your desperate. When complete you will need to reprime the fuel system by giving several squeezes of the fuel bulb up in the back corner behind the battery.

Other things to try are to replace the air filter and run some injector cleaner through the system.

Report on how you get on and good luck.

Click to expand...

Same here, with the few seconds of smoke on start up.

Pretty sure i've not got a fuel leak, replaced air filter,crankcase breather and cleaned EGR valve last week.(nothing wet under engine cover).

I'm doing the rest of filters and engine oil at the weekend.then IRD auto box and rear diff.

Edit: i use millers all the time,usually at double dose.

pardec said:

Same here, with the few seconds of smoke on start up.

Pretty sure i've not got a fuel leak, replaced air filter,crankcase breather and cleaned EGR valve last week.(nothing wet under engine cover).

I'm doing the rest of filters and engine oil at the weekend.then IRD auto box and rear diff.

Edit: i use millers all the time,usually at double dose.

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How does the car drive? Is it lively and fast or slower than a stunned slug? If it isn't leaking fuel then its got to be burning it and burning it right. Therefore, either you've got some kind of tuning module fitted or something else is wrong. For example, if the engine coolant sensor to the ECU (Tis a different one that feeds the gauge on the dash) was reading low then the ECU will increase fueling to the 'cool' engine. This is a trick some of these cheap tune up modules performed as I understand it.

If all else fails then it might be worth getting the ECU onto the compter and see what is going on.

Darmain said:

I wonder how many of those 10,000 odd posts you've made just say 'Burn it'? I'm sure a simple script to search and delete those posts would save so much disk space on the server. Tis getting a bit boring now Bob.....

Click to expand...

Trouble is, this would bump him back down to junior member status.

Darmain said:

How does the car drive? Is it lively and fast or slower than a stunned slug? If it isn't leaking fuel then its got to be burning it and burning it right. Therefore, either you've got some kind of tuning module fitted or something else is wrong. For example, if the engine coolant sensor to the ECU (Tis a different one that feeds the gauge on the dash) was reading low then the ECU will increase fueling to the 'cool' engine. This is a trick some of these cheap tune up modules performed as I understand it.

If all else fails then it might be worth getting the ECU onto the compter and see what is going on.

Click to expand...

Thanks for your help so far.

It seems to drive ok i wouldn't say it was lively and fast, but i have nothing to compare it to. There's definately no tuning module fitted.

Could it be the MAF? i was planning on getting a new MAF and a synergy 2 soon.

Will i have to go to a LR main agents to get it checked further?