Thread: TD5 Clatter at low revs

Ok this is a bit weird,
I fitted a snorkel last night and swapped the old MAF with a spare I had lying around - just to test if it was a good one

The Clatter is totally gone, she's very civilised now. The new MAF reads 45 on idle compared to 55- 60 of the old MAF
It certainly wasn't induction noise related, so not sure if the snorkel fitting has any relevance.

EU2 mafless tune on a bastard NNN500250 ECU < but was doing it before on the old msb ecu


*Just went for a long drive, got the engine good and warm, still clatters - but now at a MAF reading of > 50.
old MAF 55 = quiet > 60 = noisy @ idle
new MAF 45 = quiet > 50 = noisy @ idle
So it cant be the MAF causing it - has to be something else. which makes sense as it's an Eu2 tune.

Originally Posted by Discosux

I couldn't do the maths anyway

If you've got time and dont mind, could you shed some light on the whole EGR delete thing with regards to tuning.
I've been reading up on the South African base maps that came out without EGR systems. Not that I could find all that much info.
Not asking for the revelation of any trade secrets or such, just some insight.

If the clatter is no issue, other than making ordering at a Hungry Jacks drive through a total PTSD inducing thing, I can live with it.
if it could be damaging to the engine, I'd like to know.

Cheers

I've got most of my information and understanding of the EGR operation on a TD5 from offtrack, his knowledge on it and all TD5 info is exceptional...

There is a thread on here somewhere discussing EGR operation, search for that.

The lack of EGR won't damage your engine, but it may use slightly more fuel, and also prevent the intake clagging up to a reasonable degree.

The clatter?

I'd forget looking at airflow and check what the rpm is with the clatter, Also check if the clatter stops at a different rpm on lift off than on Accel.

Hope that makes sense.

No EGR will result in less fuel used and better throttle response and your engine will love you for getting rid of it.

Originally Posted by Graeme

No EGR will result in less fuel used and better throttle response and your engine will love you for getting rid of it.

My info would suggest more fuel used due to the non reburn of exhaust gases when coasting, do you disagree with that?

That's a genuine query as well!

No, I don't agree due to the theory and the experience of getting significantly better fuel consumption after EGR was disabled. Lighter throttle is required to get the engine to do the same work because combustion is more effective.

Originally Posted by Graeme

No, I don't agree due to the theory and the experience of getting significantly better fuel consumption after EGR was disabled. Lighter throttle is required to get the engine to do the same work because combustion is more effective.

What engine was that though? Newer ones possibly behave differently due to tighter emissions requirements.

Unfortunately (I guess) I don't have one with the EGR still installed to check fuel demand with EGR active vs not.

I'm not dogmatic on this either way, was just curious as to reasoning.

Cheers
James

Originally Posted by shack

I've got most of my information and understanding of the EGR operation on a TD5 from offtrack, his knowledge on it and all TD5 info is exceptional...

There is a thread on here somewhere discussing EGR operation, search for that.

The lack of EGR won't damage your engine, but it may use slightly more fuel, and also prevent the intake clagging up to a reasonable degree.

The clatter?

I'd forget looking at airflow and check what the rpm is with the clatter, Also check if the clatter stops at a different rpm on lift off than on Accel.

Hope that makes sense.

Hi mate, the rpm does not change at all, rock steady at 740rpm with and without clatter
But the ECU is doing something with the fuelling to cause a higher airflow reading when she clatters.
Crazy how it can suck more air yet retain constant rpm

Light acceleration it clatters if already in a clatter state, Heavy acceleration it's good
Lift off - I haven't noticed

I realise EGR is buried deep in the program and not tweakable.
If it's just an egr issue - I can live with it. But if there's a hack to fix it I'm all in on that
A Toyota mate reckons the injectors are NBG. I doubt it though.

Funnily enough, I haven't tried it yet with the MAF unplugged - From my understanding all the MAF did on eu2 was supply an input the egr control?

Originally Posted by Graeme

No, I don't agree due to the theory and the experience of getting significantly better fuel consumption after EGR was disabled. Lighter throttle is required to get the engine to do the same work because combustion is more effective.

I dont think you can correlate lighter throttle with anything meaningful on a fly by wire ecu.
The computer would have a large say in the actual fuelling.

I do like the idea of feeding an engine waste NOX, but yeah, not with all the other stuff in the exhaust

There's a UK mob selling a mini fuel computer for the TD5, gives instantaneous fuel readings and average and a few other things. Pretty cheap unit as well