Overboost?

sierrafery said:

The best way to diagnose that would be a boost gauge corroborated with live MAP reading cos it can happen to have normal boost shown by the gauge while the ECU to cut fuelling as the MAP reading exceeds the overboost limit which can be due to bad MAP or AAP sensor....the gauge will only show that it's not overboost in reality it would not explain why the ECU cuts fuelling also a quite similar symptom like overboost cut off occurs if the MAF reading exceeds 680 and a boost gauge can't help with that

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your also forgetting the turbo configuration has been changed from stock
regardless of map sensors and any other sensor the OP has changed his turbo and played with waste gate settings he made some slight power but only over boosting on the higher speeds

my point is that a boost gauge can help his situation due to the fact he is just guessing turbo waste gate settings and it apears he has boost creep on the higher the engine load side specially at 70 mph = 112 kph i also once had boost creep from 90 kph and climbing since our speed limits are 110 kph ..this can be a simple fix and bleed off some air via a bleed off considering i also use LPG for extra power

what i cant get my head around is when member eightinavee reckons boost gauges and worry gauges are a waste of time

eightinavee said:

@ozzyboydeano - The OP's question is about overboost, what is actually going on in the inlet manifold is irrelevant to the engine ecu which makes the actual decision about what the boost pressure is.What is relevant is what the map sensor tells it,if it see's more than 230Kpa it will cut fuelling - simple as that.That is what the OP needs to know right now to diagnose his issue,granted a dash full of worry gauges can be useful,but only after the thing is set up and running nicely.Then and only then can you use them as a benchmark of normal operation.

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if i remember correctly the map sensor is located on the manifold and there is a hole for the sensor to read manifold pressures and temps so yes the inlet manifold pressures are important ..to make boost you need fuel and air the more fuel means more heat / kinetic energy this then when A/R ratio comes into pay

as you may of missed the OP mentions he had lots of lag and no boost he then goes on to mention he adjusted rod length now he has some power then mentions he is fuel cutting at higher speeds in top gear while climbing up to 70 mph ..so a boost gauge will detect this as the manifold pressure maybe rising due to boost creep ... or do you still think that every gear and regardless of speed does not have an affect on engine load ?

as for the worry gauges does the td5 tech tools give readouts on fuel pressure and what about EGTs ....also on the td5 dash where is the oil pressure gauge ? on top of that how accurate is the coolant temp gauge on the dash

like i say its a personal preference many add gauges to monitor curtain things or to diagnose curtain issues and a boost gauge is one of them as its helped me many times in the past... diagnosing waste gate issues and fuel pressure issues combined with fuel pressure readings

bankz5152 said:

On me phone wam

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dont let it worry you ..only the weak pick out spelling and gramma mistakes .its the only way for the uneducated to get out of a situation before its gets to heated for them .........wam. stock yeah right this means i should leave my EGR system in place ?

This has become a very good thread It's given me loads of inspiration to fix the boost guage and install a water temp guage on the RS haha!
I'm going to install boost and intake temp guages to the Discovery, I don't drive it that often maybe once a week in the winter so I've turned the actuator back about 4 turns to be safe until the weather picks up. I can't fit the Discovery in the Garage in the dry lol.
I've bought that Nanocom thing now so I'm gonna make use of it and have it dash mounted monitoring everything aswell

RustySkull said:

This has become a very good thread It's given me loads of inspiration to fix the boost guage and install a water temp guage on the RS haha!
I'm going to install boost and intake temp guages to the Discovery, I don't drive it that often maybe once a week in the winter so I've turned the actuator back about 4 turns to be safe until the weather picks up. I can't fit the Discovery in the Garage in the dry lol.
I've bought that Nanocom thing now so I'm gonna make use of it and have it dash mounted monitoring everything aswell

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your nano com will work well but its not a tool to be permanent installed either its a tech tool and you may also find when the tech tool is constantly powered with ignition off due to the diagnostic port configuration

this is when when my worry gauges come into constant play i can start my engine then drive off and read things from get go without pressing a button ,,,,hopefully on your rs the stock coolant gauge is the same to my accurate tdci ford focus coolant gauge also responds well ....but the td5 stock coolant gauge doesn't really tell you much

Tho the nanocom wont read the ECU with power off but will read the SLABS in ignition stage 2

ozzyboydeano said:

your nano com will work well but its not a tool to be permanent installed either its a tech tool and you may also find when the tech tool is constantly powered with ignition off due to the diagnostic port configuration

this is when when my worry gauges come into constant play i can start my engine then drive off and read things from get go without pressing a button ,,,,hopefully on your rs the stock coolant gauge is the same to my accurate tdci ford focus coolant gauge also responds well ....but the td5 stock coolant gauge doesn't really tell you much

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I won't leave it in the car, only when I'm driving to see what's going on until I have the guages installed.
I have a device that's the same for the RS, I can't remember the name of it though... The logo is VT anyway... But I often dash mount that and have it on the screen that shows oil, intake, water, boost etc... Beause the MK1 RS's didn't have a water temp gauge on the dash, because Ford thought it would be a good idea to put a silly little boost gauge instead.

Anyway, I won't ve leaving the Nanocom in the car while I'm away from it, I won't ever see it again lol.

RustySkull said:

I won't leave it in the car, only when I'm driving to see what's going on until I have the guages installed.
I have a device that's the same for the RS, I can't remember the name of it though... The logo is VT anyway... But I often dash mount that and have it on the screen that shows oil, intake, water, boost etc... Beause the MK1 RS's didn't have a water temp gauge on the dash, because Ford thought it would be a good idea to put a silly little boost gauge instead.

Anyway, I won't ve leaving the Nanocom in the car while I'm away from it, I won't ever see it again lol.

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same goes with the td5 they forgot to install an oil pressure gauge ..and at the same time coolant gauge that is useless ....... but a silly boost gauge can become in handy at times

on the flip side my ford focus has a really good stock coolant gauge

ozzyboydeano said:

same goes with the td5 they forgot to install an oil pressure gauge ..and at the same time coolant gauge that is useless ....... but a silly boost gauge can become in handy at times

on the flip side my ford focus has a really good stock coolant gauge

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I called it a silly boost gauge because it's a dial with nothing on it and 1Bar written at the top. When it was stock it always went to 1Bar so really a completely useless gauge put there for rich people who would have bought the car new and had no idea what 1Bar meant (Not that it was a correct reading).
I'd rather a water temp gauge than a boost gauge anyway, I'd rather know if it was about to over heat before it's too late than if it's low or high on boost. But that's just me lol.

RustySkull said:

I called it a silly boost gauge because it's a dial with nothing on it and 1Bar written at the top. When it was stock it always went to 1Bar so really a completely useless gauge put there for rich people who would have bought the car new and had no idea what 1Bar meant (Not that it was a correct reading).
I'd rather a water temp gauge than a boost gauge anyway, I'd rather know if it was about to over heat before it's too late than if it's low or high on boost. But that's just me lol.

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this is why we install a EGT gauge it more of an early warning indication compared to coolant reading ..then we also have vehicles that run engine oil temp in side the sump this is also another early warning indication over coolant readings

Yeah but it's rare to find those installed factory lol. I think every car running over 150hp should have them. My van has NONE at all! Only diesel! Stupid if you ask me lol.

FFS, I'm just trying to answer the OP's original question from the point of a diagnostic process.Feel free to fit any gauges you like,they may or may not help you,but in the OP's case he needs to see what the ecu is seeing,I can't state it any more simply than that.

RustySkull said:

Yeah but it's rare to find those installed factory lol. I think every car running over 150hp should have them. My van has NONE at all! Only diesel! Stupid if you ask me lol.

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just finished installing a EGT gauge to a jackaroo as this engine is prone to cracking cylinder heads just like the Td5... however the jackaroo runs stock ecu simple mods are exhaust and egr ... the owner needs to change his driving style when towing up hill fully loaded towing his caravan maybe he asking to much out of the 4 cylinder engine... and his coolant gauge is not quick enough to the point of cracking a head ..an egt gauge also comes in handy in case there is an injector compensating or leaking issue ... so regardless of HP and EGT gauge is classed as an early warning device

the stock engines i work on they also have a sensor inside the engine oil sump this does 2 things engine oil level ..and engine oil temps.... the engine oil temps is a very good early warning device

eightinavee said:

FFS, I'm just trying to answer the OP's original question from the point of a diagnostic process.Feel free to fit any gauges you like,they may or may not help you,but in the OP's case he needs to see what the ecu is seeing,I can't state it any more simply than that.

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no mate it seemed like you wanted to be clever
some times its not as simple as you think
i love your diagnostics skills though
FFS it apears you never read the OP diagnostics and findings
FFS you also missed when he has added in a larger turbo now changing the A/R ratio
FFS you missed the point when he re adjusted rod lengths
FFS you missed the point he now has boost but not as good as the original turbo more lag
FFS you missed the point when he has issues ie climbing up to 70 MPH in 5th gear

i also have to ask why did he not over boost while only to find up to high speeds ? ( love your diagnostic skills by the way )
i have even thought about it my self grabbing a turbo from a truck only to install it on a 2.5 litres engine but what would be the side affects ?

lets be real mate playing with turbos without any readings ? is asking for trouble

Not trying to be clever,I have nothing to prove to anyone.Just trying to help someone with a problem.Rustyskull asked a question - What is considered overboost and is that what his truck is suffering from.He stated that the only change to his Disco is the turbo,its still running a stock ecu tune. I answered that question for him,stating that he needs to see what the ecu can see to ascertain what is causing his juddering/power loss under full throttle/load conditions.As James Martin stated this is classic TD5 overboost symptoms.This is very easy to prove via live data from the ecu,and is how I and all of the 60 odd garages I work with would prove the issue.No extra padding or complications need to be discussed or argued over at this stage.Further on when ecu boost values can be seen and recorded it will be the time to suggest other tests or addtions to the car.Diagnostics need a clear and orderly approach,one step at a time.
Luckily Rustyskull has a Nanocom on the way and seems happy with the way forward.Your childlike rantings offer no extra help to him.

I must start off by saying I totally appreciate ALL of you and your posts.
I started this thread to indeed find out what happens when this TD5 goes into Overboost mode because I suspected that is what mine was doing. That question was answered so thank you.
But most of you also offered additional help, which is fantastic. None of you know me, I rarely post on here so none of you know the extent of my knowledge so you just assume I know nothing and tell me from the basics which again is great I must thank you all so much!
I do however know messing with boost without gauges, data and temp readings is dodgy, but I won't lie I am probably one of the biggest bodge jobs you'll ever meet when it comes to my own stuff. I found myself in a situation where I had a new turbo and no boost or power so I tried to do what ever I could to get it drivable. Risking damage to the engine, I know. I do agree manual gauges are very handy and sometimes a must, but I do also agree that seeing date as the ECU sees it is very helpful because there could be a sensor that's gone faulty and giving a funny reading etc...

What I'm trying to say is, all of your help means a lot to me and whether you agree with eachothers help and advice or not it's all givien me different ways of looking at how to move on and work out what the issues are with my Engine.
Than you all and I hopw you are all having a great new years day!!!!

eightinavee said:

Not trying to be clever,I have nothing to prove to anyone.Just trying to help someone with a problem.Rustyskull asked a question - What is considered overboost and is that what his truck is suffering from.He stated that the only change to his Disco is the turbo,its still running a stock ecu tune. I answered that question for him,stating that he needs to see what the ecu can see to ascertain what is causing his juddering/power loss under full throttle/load conditions.As James Martin stated this is classic TD5 overboost symptoms.This is very easy to prove via live data from the ecu,and is how I and all of the 60 odd garages I work with would prove the issue.No extra padding or complications need to be discussed or argued over at this stage.Further on when ecu boost values can be seen and recorded it will be the time to suggest other tests or addtions to the car.Diagnostics need a clear and orderly approach,one step at a time.
Luckily Rustyskull has a Nanocom on the way and seems happy with the way forward.Your childlike rantings offer no extra help to him.

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firstly asking or naming a member for help like james martin this is a weakness as your forgetting the type of issue the OP has has in the first place
it certainly not a ****ing contest either . i would just like to know how a boost gauge wont work in fault finding ?
i never said an electronic reading isn't the way to go either and yes a nonocom is a useful tool to have... and the OP will be to discover other issues and run other tests along the way forward

but i still ask why wouldn't a boost gauge see a boost spike or over boost or boost creep? hopefully james martin backs you up on this . ........ and like i said my boost gauge works well touch wood ... i have used my boost gauge also to diagnose over boost as well as loosing boost scenarios and some small boost spikes ...also its a nice feature to have you can become custom how the engine responds and drives while comparing boost levels in each gear with rpm/ road speed as well as towing specially at higher speeds when the boost gauge works more than the tacho does ie engine load
like i said your diagnostic skill lack. and when they do you cry out and named members ... yes one step at a time i agree but many people miss a few steps and jump to far ahead start the end and finish at the beginning
you need to start with the basics first along with the information provided

the over boost has cured while the larger turbo was fitted .... as there was no mention about over boost with the stock turbo... and he isn't over boosting either while driving through other gears with the larger turbo .....but only noticed this in 5th gear while slowly climbing up to 70 MPH like i said you boost gauge can move more than the RPM reading
i can concur and relate with this issue even with the stock turbo set up ..... as our freeways /motorways are 100 kph now slowly accelerate due a speed limit change or over take to 110 kph zone .... i would over boost on the stock turbo as i had boost creep due to waste gate issues .... and this was with out an electronic reading ps do the math an work out KPH to MPH

now that he has changed the A/R ratio to a larger turbo his issues has appeared...now that the inducer an exducer of a turbo impellor play a big roll in how that turbo spools up to make power as well as when the turbo makes power under load ie more heat . for kentic energy means efficiency .... now if the waste gate isnt set correctly or to small for the job he will notice boost spike and or boost creep .... a simple boost gauge reading will detect this as long as the boost gauge reads the correct area like the manifold

RuskySkull has a fair idea what needs to be done as he was asking about a map earlier ... whether it was to tone it down or waken it up in curtain areas... this depends but this depends on his set up and information provided also

a simple bleed off may work.... but who knows because a simple boost reading is just to hard

i have a few turbos laying around in my work shop from 16.1 litre engines.good to go as well as a few VGT turbos from smaller engines .. you do get the newbies who mentions why not install this on your 4wd it would be a beast .... . hence i dont want to wait 3 weeks before it kicks in and when it does its to late

Ozzyboy, I have nothing to prove,no intention to upset anyone,just like to help if I can. Your last post is difficult to read,as if it was typed in a rage. I'll happily delete it all if you wish.

eightinavee said:

Ozzyboy, I have nothing to prove,no intention to upset anyone,just like to help if I can. Your last post is difficult to read,as if it was typed in a rage. I'll happily delete it all if you wish.

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i do apologise for for punctuation and my typing skills

if this is more basic for you
i ask
why wont a boost gauge work ?
its very simple the only reason why we are having this conversation is because you mentioned that a boost gauge wont work

eightinavee said:

The way to see the boost is not through a boost gauge,but as the engine ecu see's it, so a Nanocom or similar is the way forward.More than 230Kpa is overboost as the Storm ecu see's it.

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now its entirely up to you to delete your mistakes so yet again why wont a boost gauge work and help in fault finding

Because quite simply it won't tell you what the ecu is seeing - as the ecu is responsible for fuelling the engine therefore making the decision of when overboost is occuring, can you not see that this is the FIRST part of the diagnostic process to give an answer to Rustyskull's original question in his first post.(Which is all I have tried to help with) Until you see what the ecu thinks is happening you have little idea of what is going on.So in this instance a dash mounted gauge may tell you the actual boost pressure which is nice if you need to know it,but not necessarily what the ecu thinks is going on.I can't make it any more simple than that, a dash mounted boost gauge will tell you boost pressure,(Within terms of its own accuracy) but NOT tell you what the brain that has control of the fuelling is thinking or doing.If it was an old 200TDI with a Bosch VE mechanical pump which Rustyskull was working with, a boost gauge would be a great help. But its not, a boost gauge will be of help further on when he has seen some live data from it and set the boost to its correct limit.