Low Rev Throttle Response, at a loss now!

sierrafery said:

??? are you sure?

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Typo....more coffee required - 235/85R 16

tweedandbriar said:

Typo....more coffee required - 235/85R 16

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Though so...

A couple of questions if I may to potentially round this off.

Could the lack of top end speed be down to the re-map? I asked for a less aggressive one, and they did that so no more jerking and jumping, but it takes an age to creep up to 65/70mph, the upside is fuel consumption it markedly improved!

There is very little (or no) throttle response at low revs' - could this be the clutch switch playing up? I have to rev it up to around 2000rpm to move off in 1st gear.

There are a couple of other issues that I am looking into, but they're not performance related - maybe another thread if I can't suss it out myself.

Thanks again!

tweedandbriar said:

it takes an age to creep up to 65/70mph,

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you didnt mention this symptom untill now... it happens with the non-remapped chip too? ...

tweedandbriar said:

could this be the clutch switch playing up?

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you said it works checked with nanocom ... watch it's live input while accelerating to rule it out

sierrafery said:

you didnt mention this symptom untill now... it happens with the non-remapped chip too? ...

you said it works checked with nanocom ... watch it's live input while accelerating to rule it out

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Hi, I didn't mention it as I wasn't sure if it was just a foible when running from cold. Also, I'd not been on a longer drive that facilitated driving at speed

I'll keep an eye on the clutch switch when driving - good plan

Interestingly, when I bought the vehicle the clutch switch was disconnected!

Re' the 'non-mapped' chip. I can't say for sure that it's a purely stock chip, just different inline with my request for a less aggressive, potentially overfueled drive. I haven't tried the other chip in since its running better. I wonder if its worth trying that again? I mean if the black smoke and jerking was down to it under/over boosting and thats getting sorted now (according to the Nano Log) maybe the mapped chip might work?

tweedandbriar said:

A couple of questions if I may to potentially round this off.

Could the lack of top end speed be down to the re-map? I asked for a less aggressive one, and they did that so no more jerking and jumping, but it takes an age to creep up to 65/70mph, the upside is fuel consumption it markedly improved!

There is very little (or no) throttle response at low revs' - could this be the clutch switch playing up? I have to rev it up to around 2000rpm to move off in 1st gear.

There are a couple of other issues that I am looking into, but they're not performance related - maybe another thread if I can't suss it out myself.

Thanks again!

Click to expand...

You should be able to set off it first without using your throttle in many circumstances.

tweedandbriar said:

Hi, I didn't mention it as I wasn't sure if it was just a foible when running from cold. Also, I'd not been on a longer drive that facilitated driving at speed

I'll keep an eye on the clutch switch when driving - good plan

Interestingly, when I bought the vehicle the clutch switch was disconnected!

Re' the 'non-mapped' chip. I can't say for sure that it's a purely stock chip, just different inline with my request for a less aggressive, potentially overfueled drive. I haven't tried the other chip in since its running better. I wonder if its worth trying that again? I mean if the black smoke and jerking was down to it under/over boosting and thats getting sorted now (according to the Nano Log) maybe the mapped chip might work?

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My clutch switch was unplugged also, plugging it back in makes little difference as far as I can tell so far.

Anaconda said:

You should be able to set off it first without using your throttle in many circumstances.

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You'll have to elaborate

More or less any car should be able to move off without throttle. Decent injection control will let it drive up slopes without touching the accelerator as it maintains revs.

boguing said:

More or less any car should be able to move off without throttle. Decent injection control will let it drive up slopes without touching the accelerator as it maintains revs.

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Blimey!

tweedandbriar said:

Blimey!

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That's how I taught my kids clutch control!

tweedandbriar said:

You'll have to elaborate

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I set off with no throttle and then accelerate once clutch is up.
Low range 1st you can start the engine in gear with clutch pedal up and off you go.

@sierrafery

Quick Update:

Seems to be driving well now. Much more response low-end revs and climbs up our hill in 3rd gear without much effort. Could the Depression Valve have been the problem all along? I'd value your thoughts on the Log below? I am tempted to turn in the wastegate a half turn to see if it improves even more - what do you think?

23_07_24

It's only one moment of higher boost in that log but lower than in the last one, the rest is irrelevant, i dont know if the DCV was the problem or not, you can tighten te wastegate as much as possible but if it doesnt go to overboost it's still not OK... the sensors are working well, any other power issues are not management related but something else which i explained in an earlyer reply at a time.

sierrafery said:

...any other power issues are not management related but something else which i explained in an earlyer reply at a time.

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Thanks....Are we talking injectors, fuel pump, I think I have gone as far as I can with the Nanocom then...where should I be looking now?

I dont like to repeat things, it was covered in some earlyer post

sierrafery said:

I dont like to repeat things, it was covered in some earlyer post

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I know, I know you don't......

....and I did note what you said in post #181. But then again, your suggestion re the Depression Valve was an afterthought so before I start booking it in for a TD5 mechanic to dig in further, I was wondering if there was anything else I might be able to look at/for with my relatively limited experience, in my own garage with my own tools. Checking the Turbo Cartridge is on the cards.

You mention, "....measure the fuel pressure with a gauge inserted instead of the FT sensor in the FPR..." - those acronyms go over my head too.

FPR - fuel pressure regulator, the FT/fuel temp sensor is in it

Can you just satisfy my inquisitive nature please.
I know I suggested a look at the anti surge switch fitted to the clutch master cylinder. Now this switch on the Defender is the opposite to that fitted to a manual Discovery. A Defender at rest the switch is in the "make" position so a multimeter across the switch will show continuity. Clutch depressed switch "open" no continuity. Can you check this with a multimeter by taking the plug off the switch and checking just the switch.
If a previous owner has had issues by replacing the switch with a new one but the wrong one will still have the same issues.

So, I think we ('I') have gone as far as we can now....it's booked in to a LR specialist to go through it with a fine tooth comb whilst we're sunning ourselves on a beach. He's a top chap with a sterling reputation and been working with Land Rovers for nearly 40 years. He'll sort it - fortunately I have the £'s to get it up to speed - pun intended.

Thanks for your help to date everyone. I will of course give an update when its done.