'fitting my decat and straight through' Becomes 'wtf have i done to my engine?!'

ok, if you have read the thread ive put up recently, you should know ive fitted my defender 110 td5 with a straight through stainless centre pipe and a decat downpipe.

Im delighted with half the result , it sounds great. But heres the problems and my informed and personal analysis...

1: When reaching top end speed between 60-70 mph, the engine jumps slightly as if it is struggling to get fuel.

2: What i can only describe as the flat spots in the acceleration curve through the gears seems to be lasting longer than usual.

3: MPG has dropped seems to have dropped dramatically but ive no figures.

4: She goes into limp mode, at about 70mph (the odd time i get it there) and it takes real easy/slow increase of acceleration to get it to this speed.

Im not using ****ty fuel, fuel filter changed yesterday, 140000 miles on the clock, bought it 10000miles ago, havent serviced it except this is my second fuel filter.

The history:

The limp mode problem has been there always but was easy to overcome by slow accelerating and ive reached speeds of 80 odd mph easy, but it has suffered since the exhaust replacement.

The fuel filter had to be changed as i let the tank run almost dry, causing ****e to be sucked into the filter, after changing i had 'crap in the filter' symptoms again for a day once or twice in the space of 3 mths. its replaced again since then.

if anybodys got any ideas or has had the same issues, help would be great.

Thanks

-Defender110- said:

The limp mode problem has been there always but was easy to overcome by slow accelerating and ive reached speeds of 80 odd mph easy, but it has suffered since the exhaust replacement.

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Has to be said .. why bother changing anything knowing you already have an issue?

Personally, I'd put everything back to standard and trace the source first, get it running correctly, then mod it. Nothing fecks an poorly engine up worse than 'go faster' bits ...

Have you thought of giving twisted performance a call and asking thier advice? they're TD5 tuning guru's and may be able to give you a few pointers. Twisted Performance - Diesel Land Rover & Range Rover Tuning And Styling Products - Defender, Discovery, Freelander, Range Rover Sport, TD4, TD5, TD6, TDV6, TDi

well to be honest, when i had the problem beforehand i didnt even consider it a problem as such because it hardly ever happened...

There's an object lesson here...

If you have a problem, sort it out before you do anything different or before it becomes a big problem.
A problem that goes away by itself can came back by itself too...

Get a specialist to check it out.
It's probably a sensor or something simple - check all the connectors are connected and secure - but don't go guessing.

Check all the service items are up to date (Your original posting says that you haven't serviced it in 40,000 miles - I hope this isn't the case...)- is the air filter clear? Are all the breathers clear? etc etc..

sorry, the way ive worded it is a bit confussing tbh, ive only had it for 10000 miles give or take, but aswell, i have changed the air filter how do i check the breathers???

-Defender110- said:

sorry, the way ive worded it is a bit confussing tbh, ive only had it for 10000 miles give or take, but aswell, i have changed the air filter how do i check the breathers???

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Bearing that in mind .. put it back to standard then get it serviced and checked properly .. has to be worth the money.

I'd look for a good independant Landrover specialist rather than a main dealer.

Bearing that in mind .. put it back to standard then get it serviced and checked properly .. has to be worth the money.

I'd look for a good independant Landrover specialist rather than a main dealer.

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I think your probably right, ill have to have a look around for a specialist so, if anyone knows a good one in the limerick (ireland) area let me know please

I'm betting it's your MAF (Mass Airflow Meter), if you unplug it and it makes no difference to the running of the car then it's very likley to be shot. Do a quick search on google TD5 MAF

you might be onto something there dazz... i dont suppose this would cause my turbo to take forever to kick in after starting the engine (first 20odd seconds down the road) ??

probably, it will run like **** and be down on power, does'nt always put engine management light up either, but it can usually be diagnosed on diagnostic machine, I've had it on a VW Golf in the past, a friend of mine who is VW independant service technition (18yrs trained and former workshop foreman at VW) told me the easiest check was to unplug the Maff and see if ther was any difference, if there was no difference then the maff was knacked, you can sometimes get away with cleaning the sensor with brake cleaner, but this is usually just a short term fix.

thanks for that, ill try unplugging it tomorrow so, its the cable plugging into this yea?? http://media.teilesuche24.net/parts/vdo/bmp/500/5WK9607Z.jpg

Yep.

And the winner is...... DAZZ!!! congratulations...... i disconnected it this morning, drove her to college, no E.M light, no difference in the engines ability... i foookin hate lectronics so what do i do now?? is it as easy as replacing the MAF unit on the intake pipes or do i need a diagnostics check to root out the origin of the problem??

Just unclip the MAFF unit from the inlet piping and replace it. Simple. Should take all of 30 seconds. Assuming it was the MAFF playing up you should see instant improvement. No need to reset anything.

just cleaned off the connection with some sand paper, stuck it back on, instant fix
Thanks for the help guys

Good stuff No need for all the pointless silly electronics though. A 200Tdi has nothing it doesn't need in terms of electrical bits and bobs and they can still wipe a TD5 in the face when it comes to emissions and fuel economy

Yea im seeing the light now, pity its too late, ah, sure ill stick a v8 in it at some stage sure

Glad to hear you got it sorted eventually. I have a TD5 110 DCPU which has had a few sensor problems. I have replaced the MAF sensor and the accellerator potentiometre (spelling??) Now that was a worry! Driving along and wham, no accelleration and an engine warning light! luckily i was only 1 mile from home on a back road and i managed to limp home in 2gear low ratio with just the engine ticking over! Gotta love diesels!

I wouldn't skimp on a major service though! Especially on a 140K engine. So now it's all sorted....Does the exhaust make much difference? I have fitted a stainless decat pipe to mine and i was thnking about a centre section replacement this summer.

pos said:

Good stuff No need for all the pointless silly electronics though. A 200Tdi has nothing it doesn't need in terms of electrical bits and bobs and they can still wipe a TD5 in the face when it comes to emissions and fuel economy

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Yeah but they dont go as quick and have less torque and power than a TD5 - especially a tuned one like wot mine was/is once new engine in and running