 | Home > Td5 > Surging and hesitations |
 
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| Dexterdog Member Since: 23 Jun 2018 Location: gloucestershire Posts: 108  |
Hi Blackwolf,
Is the throttle position sensor the little box on the side of the throttle pedal that comes with the pedal itself ? If it is then yes changed that and made no difference. If it's something else can you direct me to where it is pls Thanks for the help[/s] |
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3rd Apr 2020 1:07pm |
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| blackwolf Member Since: 03 Nov 2009 Location: South West England Posts: 17443  
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Yes, that's it. Rules that out then.
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3rd Apr 2020 1:57pm |
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| Dexterdog Member Since: 23 Jun 2018 Location: gloucestershire Posts: 108 |
Hi Chaps,
I have made some progress and I have now found a way to reproduce the problem consistently. Previously the problem would only be present on light acceleration and intermittently. Happens when cruising say at 50mph but also when slow in low ratio off road. Sometimes slight hesitation (usually when cruising but can be kangarooing when driving slowly. Drive it hard and no problem. However reproducing was hit and miss and sometimes would drive fine for miles I have now found that if I back off the wastgate actuator all the way, the problem becomes easy to reproduce and is present in more of the first part of the accelerator pedal travel (once the turbo gets going the problem disappaears), wind it back to normal position its less obvious and only for less of the pedal travel, wind it on another thread, it goes away more and for less of the pedal travel. That says to me the problem is off boost because backing off the actuator makes it present more and its more obvious? I think that once the turbo is coming into play earlier (which I am doing by adjusting the actuator) the problem disappears. I cant get rid of it completely by adjusting the actuator but I can influence it and make it more or less obvious and more persistent What I need help with is interpreting what that could be other than the long list of things I have already gone through already ...see below. Any help gratefully received ! (all usual main culprits checked and changed, EGR delete, MAF, FPR, Injector seals, injector harness, loom now dry and no oil at red plug, fuel filter, no fuel leaks anywhere in system that can be seen, fuel temp sensor changed, turbo no play, intercooler pipes all ok, been remapped and map checked, wastegate actuator moving freely, tps on pedal ok) |
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16th Jun 2020 3:43pm |
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| rallysteve Member Since: 10 Feb 2014 Location: Cumbria Posts: 2237 
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Have you checked and cleaned the MAP?
Steve 02' 110 TD5 Double Cab Rebuild Thread |
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16th Jun 2020 3:56pm |
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| Dexterdog Member Since: 23 Jun 2018 Location: gloucestershire Posts: 108 |
MAP was in hell of a mess but from what I can see thats not unusual until EGR delete done. Now cleaned up.
In terms of testing, I have disconnected for short drive and the problem still persists. Not sure if that is telling me its not the MAP or the MAP is dead ??? Is there any other way of testing it ? |
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16th Jun 2020 4:05pm |
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| achuakh Member Since: 12 Apr 2012 Location: Singapore Posts: 158  
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at this point, there's not much you can do than to use a diagnostic tool that can log the system request when taking it for a drive and look for any anomalies vs randomly changing parts on the vehicle.
if you can get hold of the fuel map from the ECU, you can reference the data from the log to those values to see if there's anything that's causing it, like hard limiting due to a particular value caused by the sensor data or the map requires a certain cheat circuit (as you mentioned it's a "stage 2" map). i've seen a lot of remap which will ramp up the "torque limiter" and then it's becomes very jerky due to it referencing the "driver demand" map directly. these are my own view and you are welcome to disagree. From the land of the most expensive land rover defenders on planet earth. At �125k for a XS 110 csw and you get to own it only for 10yrs! Please find me a good reason to stay on this island. |
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19th Jun 2020 10:26am |
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| Dexterdog Member Since: 23 Jun 2018 Location: gloucestershire Posts: 108 |
Hi Folks,
Well I am a long way down this route. I promised to update as I found the issues. I had oil in the loom which was throwing various fault codes that would not clear. Loom now changed but still have the hesitation and stutter. I am fairly sure I have got to the root cause but could do with a wee bit more help if poss. By adjusting the wastegate actuator I could increase the amount of pedal travel that the stutter / hesitation lasted for. Once the turbo spooled up the hesitation went This led to more investigation around this area and I have now found that the wastegate spring is broken (I think). My understanding is that the wastegate should spring back into position. Mine flaps around with no resistence, . I am hoping this is the cause of my problem which is why just as the turbo comes on boost I get a hesitation but can then "drive "through the problem and the car drives fine. Would stutter / hestitation be a symptom of the wastgate spring being broken ? Can you rebuild the spring? or is it a new turbo ? Thanks for any help |
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28th Jun 2020 12:13pm |
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| mk1collector Member Since: 17 Sep 2009 Location: West Yorkshire Posts: 6769  
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Unplug the MAF and drive it around for a day and see if it feels better. Ray
My build thread http://www.defender2.net/forum/topic17615.html |
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28th Jun 2020 12:30pm |
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| Dexterdog Member Since: 23 Jun 2018 Location: gloucestershire Posts: 108 |
Hi, thanks for reply but I am way past unplugging MAF in terms of investigation. Def narrowed down to when turbo just coming on boost and as said wastegate appears to be broken
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28th Jun 2020 12:50pm |
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| roel Member Since: 08 Aug 2009 Location: Lelystad Posts: 2039  
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The actuator has indeed a spring. the turbo pressure pushes against the spring and at the adjusted pressure it will compress the spring and the bypass will open. It is hard to pull enough on the actuator rod to get it moving. So if the rod that comes out the actuator is moving freely the actuator is broken.
As a test you could adjust it as short as possible so it won't move. But note that the bypass will not open so you could get high turbo pressures and the ecu will reduce power. As I read you problem is at low rpm so I assume below 1800 rpm. As you stay below that I think you will be safe. Roel 1984 90 2.5 na Diesel - RR V8 (1994-2001) 1997 Camel Trophy Discovery 300TDI (2001-2009) 2005 G4 Discovery III 4.4 V8 (2008-2018) It's gone but it still hurts. 2003 90 Td5 (2009-now) |
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28th Jun 2020 7:49pm |
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| custom90 Member Since: 21 Jan 2010 Location: South West, England. Posts: 20446
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Try replacing the MAP & MAF. I know it’s not a cost you’d like to hear but I found cleaning does not always work.
Eventually, service life comes to an end and performance is jeopardised. Also, have you had a look at the clutch switch? I believe on a TD5 you can simply unplug it. (Puma is not as simple.) Then there is the turbo actuator is it free and moving correctly? If it was a Puma the VCV can be very similar in these problem you’ve described when it’s not working correctly too. I do t know much about the TD5, but these things I’d look at. Definitely sounds fuel or air metering related but things like the clutch switch can cause odd issues. Make sure grounding points and battery clamps are all clean and tight too. No Guts, No Glory. 🇬🇧🏴🏴🏴🇮🇪🇺🇸⛽️🛢️⚙️🧰💪 |
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29th Jun 2020 11:21am |
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| Dexterdog Member Since: 23 Jun 2018 Location: gloucestershire Posts: 108 |
Thanks, MAF replaced. MAP swapped for another (lent by a mate) and made no difference. Actuator is moving freely as is wastegate arm (now realise there is no spring but it must drop back into hanging straight down to be truly freed off)
Any other suggestions ? Clutch switch - will try disconnecting next as not tried that yet  |
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29th Jun 2020 11:34am |
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| custom90 Member Since: 21 Jan 2010 Location: South West, England. Posts: 20446
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Anything free is worth a shot.
No Guts, No Glory.
🇬🇧🏴🏴🏴🇮🇪🇺🇸⛽️🛢️⚙️🧰💪 |
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29th Jun 2020 1:45pm |
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| Dexterdog Member Since: 23 Jun 2018 Location: gloucestershire Posts: 108 |
Hi Chaps,
Sorry to ask for yet more help. Any turbo gurus out there ? I had an idea today. I took the bonnet off and drove down the road watching the actuator. It does not move at allno matter how much the turbo spools up. The wastegate is free (I have diconnected the arm and freed it off) I am guessing (hoping) the actuator is knackered. If the diaphragm or spring in the actuator is broken would that cause stuttering just as the turbo starts to spool up....poss through pressure being pushed the wrong way through the actuator ? and then once the turbo really gets going it drives fine ? I am guessing it would also explain why it goes like a rocket once you have it wound up because the turbo pressure is not being released ? |
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30th Jun 2020 9:28am |
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