AuthorTopic: disco 300 tdi flat spot  (Read 2092 times)

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Offline latchy

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disco 300 tdi flat spot
« on: May 15, 2008, 09:08:48 »
Hi can anyone tell me how to get rid of the 300 tdi flat spot under 2k revs

Offline Disco Matt

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Re: disco 300 tdi flat spot
« Reply #1 on: May 15, 2008, 10:20:11 »
There are a few things - assuming you've given it a service (oil change, etc) and there are no underlying problems like collapsed hoses or a knackered fuel lift pump?

I found that getting rid of the centre silencer helped a lot with this problem, you can buy a replacement pipe or replace the whole exhaust. If your front downpipe has a Cat then it'd probably be worth swapping for a plain one or just cutting out a section then welding a new one in, as front downpipes for these aren't cheap. Also may be worth giving your intercooler a flush out, I'm not sure if that would affect low revs but it'll make the engine much perkier. Blanking off the EGR valve may also help, certainly your engine will thank you for it.
1996 Discovery 300TDI. She's got it where it counts...

Offline Disco-Ron

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Re: disco 300 tdi flat spot
« Reply #2 on: May 15, 2008, 19:47:43 »
Simple, go and visit Allisport, like i did today!!!

Full frontal intercooler, ITG filter, silicone hoses, EGR removed, all fitted and set up properly, £546 all in..... and i can tell you the low donw torque is amazing..... i can go down to 1200 revs in top and still pull away cleanly, admitedly not rediculously fast, but it pulls cleanly all the way to 60mph...;)
gone from 200tdi.... to 300tdi... still with loads done to it, in fact, even more than the last truck...LOL!!!

Offline SteveGoodz

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Re: disco 300 tdi flat spot
« Reply #3 on: May 15, 2008, 22:03:27 »
The reason it's flat below 2000 rpm is that the turbo doesn't generate any usable boost below 1800. This isn't a fault ~ Land Rover designed it that way because it helps with traction when pulling away on really slippery surfaces: less torque less wheel spin.

You can improve things by tweaking the turbo, pump and inter-cooler or maybe removing any cats in the exhaust as previously suggested. Cheapest remedy of all is to give it some revs  :lol: :lol:
Regards

Steve G
"Paddy" a 1996 3.9 V8 ES Auto Discovery
A re-imported Japanese model running on LPG

Offline Disco Matt

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Re: disco 300 tdi flat spot
« Reply #4 on: May 15, 2008, 22:50:20 »
Do silicone hoses make a huge difference, and would it be worth replacing 12 year old hoses anyway? They don't seem to be leaking or collapsed, just wondering if it's worth spending £50 on a set?
1996 Discovery 300TDI. She's got it where it counts...

Offline Disco-Ron

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Re: disco 300 tdi flat spot
« Reply #5 on: May 16, 2008, 17:22:51 »
replacing the hoses does very little, if anything, but whilst i was having the intercooler done, it seemed wise... also, the top hose doesn't now have that sillt egr thing in it...!!!

I still have the cat in my exhaust, but not for long!!  and even with it, i can still drop the revs right down and still accelerate...!
gone from 200tdi.... to 300tdi... still with loads done to it, in fact, even more than the last truck...LOL!!!

Offline Timi

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Re: disco 300 tdi flat spot
« Reply #6 on: May 17, 2008, 15:16:29 »
Hi can anyone tell me how to get rid of the 300 tdi flat spot under 2k revs

I just noticed all the threads took into account the tuning mod changes that could be made,

Another point is do you have large tyres as this can also result in a large flatspot as well as reduced performance.

I think my 300tdi has a flat spot around there as well (when it is wearing its mud terrrains) but not as obvious when
wearing its road tyres due to the reduced rolling resistance of these tyres.

I have fitted large intercooler and have tweaked diesel pump and recently rebuilt turbo which has helped things

Does your engine rev out easily to 4000rpm? as it could be an injection timing issue.

Timi  :cool:
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Offline Disco Matt

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Re: disco 300 tdi flat spot
« Reply #7 on: May 17, 2008, 18:11:11 »
To be fair, mine on standard size A/Ts always had a tendency to bog down when pulling away, still will on hill starts. It revved perfectly, but was just a bit gutless at low revs.
1996 Discovery 300TDI. She's got it where it counts...

 






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