TD5 lack of power FIXED

Hi People,
new here and new to being a TD5 owner.

I've had my 2006 37k TD5 a month and have never floored it to see the true power. I drove it back from Scotland and it reached 75mph no probs although i let it build gradually and never floored it. It still felt ok though, not lack of power id say.

Upon cleaning my engine i noticed the MAF was full of dirt and the gauze was bent and broken. I cleaned and straightened. This then made my landy not go over 50mph and feel like the turbo wasn't cutting in. I unplugged the MAF and it went like stink.

No warning lights at all with the MAF plugged in our out.

Then after 1 week of running unplugged the power has reduced all of a sudden? Very noticable, the turbo seemed to cut in low revs and now hardly but still does cut in. I have no rev counter.

Anyway the new MAF arrived,

Fitted a Bearmach MAF and I thought it would run better than unplugged but seems held back somewhat, not as bad as not reaching 50mph, it will still do 70-80 no probs but there is not the performance i was expecting.

I really felt the turbo when i put my foot down on my 300TDI.

Being a Scania Master Tech I Know the importance of sensors etc but I have no equipment whatsoever to see what is happening.

The MAP is clean, the wastegate moves, the EGR moves, it looks very clean inside, no pipes appear perished or broken. Air filter, air filter box and trunking are clear.

Am i missing something, is this how TD5's are?

Are they better Re-mapped or defaulted ECU maps when sensors are unplugged?

I have also unplugged the 2 Vaccum valve plugs which didn't bring a light on but did make a little difference in power/turbo cut in at lower rev range with new MAF than when plugged in.

My main query is;

1. Why do no warning lights come on when plugs are unplugged?
2. Why did my TD5 run super with the MAF unplugged but then after a week all of a sudden start to lack power again?
3. With my new MAF fitted, is this power output standard? Will reach 70-80 but just seems lacklustre?

Many thanks to people with more landy experience than myself

Lee

A standard TD5 Defender while not fast should feel lively enough, pulling well from about 1500rpm and achieving an indicated top speed of about 90mph on the flat (where legal).
It should climb any reasonable hill on the road in fourth gear as long as you are doing at least 30mph.

Thanks for the reply lightning.
I have just adjusted the wastegate rod a few turns to 13 threads showing,i read on another forum and the figure was 11-14 threads.
With my new maf plugged in she now runs as what u would say was acceptable. Maybe the wastegate actuator spring is worn/broken/breaking.
My defender pulls well from 30mph in 5th.

Ill road test more tomorrow to check properly across all rev ranges and speeds but as i say just a slight adjustment on the rod and she feels good.

Iirc the td5 turbo actuator shaft that passes through the turbo can seize, well worth a wiggle with some pliers.
Other sensor that causes lack of grunt is the MAP one on the inlet manifold, the correct resistance readings at different temps are on google.
Is your fuel pump running for 10 secs when ign first turned on?

Look on the bright side at least its faster than the P cab 5 banger just!

I would buy a new genuine MAF, the Bearmach one wont last long. I've had two that have failed in less than 2 months. Got a refund and bought a genuine one which has been on for over a year now.

90 is about the top speed for a standard TD5.

It runs better when the MAF is unplugged as it swaps to the default settings, not live s

Thanks for all your replies guys but ive fixed the old girl.
She runs like a dream now, plenty of turbo on lower revs.

So my MAF was def u/s but after replacement and plugging back in i dnt think i was ready for the revert back to standard. After many a thread read ,there was this dead spot called the passion zone?

Whatever my problem was, i adjusted the turbo wastegate rod a few turns to 13 threads, troughs. Peaks n troughs, so 13 troughs.

When i bought this vehicle it was mud ridden, airbox water outlet full. MAF airflow half covered in mud/hay weave (i got from a scottish farmer) which as i believe speeds up airflow (bend a hosepipe) so anyway once i cleaned this, this is when my troubles started. Now right or wrong i have adjusted the wastegate but she feels lovely.
The original green factory sticker was on the wastegate rod but who's to say the spring hadnt weakened after 10 yrs.

Anyway, she's golden now!

Thanks for all ur suggestions