raywin said:
It's true that any restriction will cause a pressure drop when the air is flowing, but the restriction of the intercooler rad is not excessive and what I have seen comparing the boost gauge to the Nanocom readings while running was more like 1 or 2 psi, also when fault finding like this it is quick and easy to tee into the actuator line, tapping into the manifold is a bit more involved.
Click to expand...

so please explain why do they crimp the discharge boost pipe ? before the intercooler ...if you have played with a garden hose you should know that restricting the flow creates pressure
trying to diagnose boost issues I certainly wouldn't T into the signal line
a mechanical gauge can be easily drilled and tapped into the inlet manifold as I did with mine and if memory serves me correct I had a 4 psi difference between signal line and manifold.....t but then again not every td5 engine is the same
 
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This sounds like a boost leak to me. I had a similar issue on my 04 TD5 110, turns out where I had tapped into the EGR blank to fit the boost gauge line it was leaking there. Normal driving it was fine but a bit down on power, however full throttle and it went mad, power drops off and comes back in the top end.

Check all your pipes boost pipes and intercooler for any splits or oil.

If it was over boost then the engine warning light should come on and put you into limp mode, however in my experience this doesnt happen every time!

It could also be down to a dying MAP sensor, see if you can get another one to test for a day or two, it may improve things. In the mean time try cleaning your current one with brake cleaner or contact cleaner, let it dry and reinstall.

Also check the the AAP sensor is connected, while it shouldn't cause too many issues sometimes they can! its a lil plug on the side of the airbox.
 
Not sure what you mean crimp the discharge boost pipe, quite honestly I have actually done quite a bit more than messed with hose pipes, I have worked on dynamic compressors for the last 22 years, I know a bit about the relationship between flow and pressure. Pressure drop over a restriction (precision orifice plate) is used to measure flow in industrial applications.
But in this case as I said the pressure drop measured at the manifold is relatively small unless load is changing quickly and given that the usual boost gauge is not a lab standard instrument it will give a good indication of what the turbo is doing especially in a case like this where what is needed is to find out is the boost going too high and upsetting the ECU or is the waste gate playing up and loosing the pressure after an initial surge.
 
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ozzyboydeano said:
you will probly find the ecu is in limp mode once it sees a over boost does the power restore if you quickly switch off IGNITION and restart it while moving (BECARFULL OF STEARING LOCK )
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I'll give this a go. What would thus tell me if it does power back on or if Not?

bankz5152 said:
This sounds like a boost leak to me. I had a similar issue on my 04 TD5 110, turns out where I had tapped into the EGR blank to fit the boost gauge line it was leaking there. Normal driving it was fine but a bit down on power, however full throttle and it went mad, power drops off and comes back in the

It could also be down to a dying MAP sensor, see if you can get another one to test for a day or two, it may improve things. In the mean time try cleaning your current one with brake cleaner or contact cleaner, let it dry and reinstall.

Also check the the AAP sensor is connected, while it shouldn't cause too many issues sometimes they can! its a lil plug on the side of the airbox.
Click to expand...

I'm not sure it's a boost leak as today I stayed in gear and gently went up the revs and it still lacked power around the same point it would do if I put my foot hard down. I've just checked the wire that plugs into side of airbox and that looks all solid.
Map sensor sounds like an idea. Just got to Google and find where it is then I'll give it a clean up.
 
MAP sensor is on the left hand side of the engine on top of the inlet manifold. Which is the big silver tube on the left. MAP is in the middle.

Still could be a boost leak, as I said mine ran fine under normal conditions but top end it wasnt happy.
 
raywin said:
Not sure what you mean crimp the discharge boost pipe, quite honestly I have actually done quite a bit more than messed with hose pipes, I have worked on dynamic compressors for the last 22 years, I know a bit about the relationship between flow and pressure. Pressure drop over a restriction (precision orifice plate) is used to measure flow in industrial applications.
But in this case as I said the pressure drop measured at the manifold is relatively small unless load is changing quickly and given that the usual boost gauge is not a lab standard instrument it will give a good indication of what the turbo is doing especially in a case like this where what is needed is to find out is the boost going too high and upsetting the ECU or is the waste gate playing up and loosing the pressure after an initial surge.
Click to expand...

so you should understand that high boost levels doesn't exactly mean more power ..also if the engine its self isn't performing well how does the turbo generate its turning power to make boost or do you still think the turbo just relys on exhaust flow .... here is an ebay link to the intercooler pipe notice it has a restriction been crushed on one end this is the pipe before the intercooler
http://www.ebay.com.au/itm/Intercoo...331660?hash=item2cb130e14c:g:No0AAOSwdGFYtMh3
 
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I'm going to clean the MAF and MAP. I read conflicting articles. What would you recommend to clean both? Will electrical contact cleaner from Halfords or maplin do the trick for both?
 
For the MAP use carburetor cleaner and for MAF there is dedicated cleaner though cleaning the MAF can't improve much, unplug it and drive it so then if it runs better with it unplugged you need a new one
 
I I'm plugged the maf and it ran the same to be honest. Thought I'd might aswel clean it if I'm doing the MAP.
 
Rufiopb said:
I I'm plugged the maf and it ran the same to be honest. Thought I'd might aswel clean it if I'm doing the MAP.
Click to expand...
also check the plug on the wire harness (for the map sensor ) ..mine come loose once ..the female pins on the electrical plug one of them decided to open up a fraction when warmed up resulting in no power
I used a sowing needle and re compressed the pins so when the plug was fitted to the sensor the female had a better grip

as for MAF and ambient sensor the engine can still be ran with out them ie if your trying to diagnose boost issues

I noticed you mention about the EGR being blanked but not deleted but have you disabled any vac lines to the actuators and electrical plugs on the solenoids ..could it be possible that the butterfly flap is sticking closed creating a restriction in the air intake as the EGR still thinks its active

remove the egr vacuum actuators make sure they are not stuck closed ..at the same time drill and tap a nipple into the intake manifold.... with the actuators removed this makes it easy to catch the drill shavings and tap in a thread ready for a boost gauge
 
Although my issue wasn't same as yours (mine was just bloody slow through all gears and struggled to get to 30), it turned out to me my MAP. Many people said they never go wrong... but mine was dead as a dodo. So, sometimes simply cleaning it doesn't work. If you get to the hair-pully-outy stage, I can send you a known good working MAP to test.
 
Well low boost levels certainly reduce power, it's easily checked, try winding your exhaust gate back and take it for a spin, the mass of air ingested by each cylinder on each stroke depends on the air density and the pressure.
My turbo is powered by exhaust gasses, I looked and there is no other source of power so yes I believe the turbo relays on exhaust flow, which would mean as the gas flow falls back then the turbo has less power to compress the intake air. turbo compressors are not linier in their output that's why they suddenly pick up at a certain speed level and you feel the boost kick in, that's turbo lag.
 
raywin said:
Well low boost levels certainly reduce power, it's easily checked, try winding your exhaust gate back and take it for a spin, the mass of air ingested by each cylinder on each stroke depends on the air density and the pressure.
My turbo is powered by exhaust gasses, I looked and there is no other source of power so yes I believe the turbo relays on exhaust flow, which would mean as the gas flow falls back then the turbo has less power to compress the intake air. turbo compressors are not linier in their output that's why they suddenly pick up at a certain speed level and you feel the boost kick in, that's turbo lag.
Click to expand...
well since you have worked on different compressors for many years
I actually work on turbos on vehcles for many years
turbo works on kinetic energy as those hot exhaust gasses expand this pushes the turbine
........how you can make boost down low in the RPM range no fuel no heat etc we will get to the inducer and exducer size of the turbines a bit later
as for lower boost pressures you can make more power with less boost and colder air is more dense

its actually a well known fact learn the basics first the vid talks about black smoke over fuelling and intercoolers etc
 
I've cleaned the maf and map. Although car feels better it still has the flat spots. I gently put the accelerator on and whether info or hard or gentle it still has the same spot. Wouldn't a boost leak or collapse hose not happen if I was very gently accelerating. It makes me think it's a mapping or sensor problem. Limp mode. Would limp mode just stop the lr going over a certain boost. As if I'm gently accelerating then limp mode shouldn't cut in?
Thanks for all your helps. I'm learning a lot!
 
sierrafery said:
There's no such thing as ''limp mode" for manuals, that's soecific for autos... from this point a tester is the way to diagnose
Click to expand...
Agree the nanocom allows you to log all perameters as you drive and can tell you an awful lot about what is happening or what the sensors think is happening. Maybe there i's someone local to you who might offer help. I have nanocom for TD5 buti aM in North yorkshire
 
sierrafery said:
There's no such thing as ''limp mode" for manuals, that's soecific for autos... from this point a tester is the way to diagnose
Click to expand...
disconnect the MAP sensor and go for a drive in a Manuel let me know if the engine has no power ?
i don't own the manuel version but the Td5 doesn't have oxygen sensors so the last map is the manifold.... if this sensor is breaking down sending wrong reading to the ecu this is also called limp mode
if the map sensor doesn't send any signal how does the ecu then tell the injectors to send a curtain amount of fuel for that curtain boost load

like i say turbo rely on heat for kenitic energy to push the turbine .. the map sensor controls this heat by telling the ecu how much fuel should be used are you saying the the manuel version will bunny hop all day long from over boost without going into limp mode ?
 
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Rufiopb said:
I've cleaned the maf and map. Although car feels better it still has the flat spots. I gently put the accelerator on and whether info or hard or gentle it still has the same spot. Wouldn't a boost leak or collapse hose not happen if I was very gently accelerating. It makes me think it's a mapping or sensor problem. Limp mode. Would limp mode just stop the lr going over a certain boost. As if I'm gently accelerating then limp mode shouldn't cut in?
Thanks for all your helps. I'm learning a lot!
Click to expand...
like I asked above is the EGR actuators still active even though the blank plate stops egr gasses but the actuators may still think its active and the actuators work as normal
the main butterfly flap that restricts the in coming charged air might be still working to a point that it isn't returning home creating a restriction or a dodgy egr soloniod holding a signal for to long

please explain how the egr is disabled on this engine

boost gauge will help ..... to see if your making boost down low in the rpm range
 
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