View previous topic :: View next topic |
Author |
Message |
Red Robbo Lifetime member
Joined: 17 Feb 2008 Posts: 4129 Location: Where ever I happen to be in my imagination but mainly Far East Sussex
|
Posted: Thu Jun 04, 2015 9:40 Post subject: |
|
|
From a Landy Site _________________ Khotso........... |
|
Back to top |
|
|
Google Sponsor
|
Posted: Thu Jun 04, 2015 9:40 Post subject: Google Ads keep this community free to join! |
|
|
|
|
Back to top |
|
|
Gribble *******
Joined: 11 Oct 2007 Posts: 8448 Location: Holset H221W
|
|
Back to top |
|
|
eithan h Moderator
Joined: 11 Dec 2005 Posts: 8195 Location: oxfordish
|
Posted: Thu Jun 04, 2015 19:06 Post subject: |
|
|
on idle a 3.0 is about atmospheric so about 14psi and at full chat they go to somewhere between 26-29psi, thats measured at the manifold pressure sensor.........when it's unblocked
those figures are obviously manifold absolute pressures so knock off the atmospheric pressure to get turbo pressure |
|
Back to top |
|
|
JP ***
Joined: 31 Dec 2006 Posts: 157 Location: Christchuch, NZ
|
Posted: Thu Jun 04, 2015 23:14 Post subject: |
|
|
Gribble wrote: |
With deference to the previous posters I would not say your EGT readings are high,a little Internet research will bear this out. |
Those readings are cruise speed temps. Acceleration is a lot slower than my previous diesel Bighorns and EGTs spiked to 960C when accelerating before quickly backing off _________________ 93 3.1 LWB Auto |
|
Back to top |
|
|
JP ***
Joined: 31 Dec 2006 Posts: 157 Location: Christchuch, NZ
|
Posted: Thu Jun 04, 2015 23:19 Post subject: |
|
|
Gribble wrote: |
Is the turbo in good condition ? |
It is a brand new turbo install 6 days ago. I checked oil flow before several times before taking it for a spin.
My original question relates to boost readings pre and post intercooler, and if this was the cause of the low (9psi) reading compared to the factory 12ish.
Low boost relates to the EGTs as there could be a leak or restriction (intercooler?) _________________ 93 3.1 LWB Auto |
|
Back to top |
|
|
JP ***
Joined: 31 Dec 2006 Posts: 157 Location: Christchuch, NZ
|
Posted: Thu Jun 04, 2015 23:29 Post subject: |
|
|
Thanks for this, I have been using very similar guideline for running diesels in the past - hence my discomfort seeing 950C+ when accelerating. _________________ 93 3.1 LWB Auto |
|
Back to top |
|
|
JP ***
Joined: 31 Dec 2006 Posts: 157 Location: Christchuch, NZ
|
Posted: Thu Jun 04, 2015 23:38 Post subject: |
|
|
Gribble wrote: |
With deference to the previous posters I would not say your EGT readings are high,a little Internet research will bear this out. |
You say here my EGTs are NOT high (950C+), then you post this as a follow up:
http://www.itocuk.co.uk/forums/viewtopic.php?t=32853&start=0&postdays=0&postorder=asc&highlight=
and it goes on to say people are getting 600C MAX on "full chat" with standard fueling.
You have a wealth of knowledge from what I have read (I love reading your posts as they have helped me immensely....many time more than I can count) , could you clarrify this? _________________ 93 3.1 LWB Auto |
|
Back to top |
|
|
Gribble *******
Joined: 11 Oct 2007 Posts: 8448 Location: Holset H221W
|
Posted: Fri Jun 05, 2015 18:24 Post subject: |
|
|
Yes , the links were to some other posts that related to your problem and the suggestion from me was based on info off other sites . I hope it was not misleading
If we go with the assumption (leave it robbo) that the pressures and temps are accurate then you have to look elsewhere for the fault such as a restricted exhaust ( the famous 3.1 exhaust flap) or fueling issues.
Now many diesel tuning websites will give you different facts and figures but from my own experience you can get a reading off a turbine housing after a hard pull of about 550 to 680 c so the exhaust gas temp must have reached that or gone higher . Many site will talk about egt's up to 1250c as a spike temp and some petrol forums even higher .
From Garrets site -Turbine wheels flowing highly-boosted exhaust gas can reach 1800°F (980°C) and higher in typical turbo vehicles, and in top-level motorsports such as WRC they can regularly get up to 1950°F (1050°C).
I'm just doing the same thing as you with a EGT sensor as i want some figures for the Hitachi turbo an then the Variable vane Garret thats replacing it ,as you know I prefer to post on something I have actually done or seen so I will have some real time data soon granted its a Mazda 3.5 engine but its pretty similar to the Isuzu . _________________ 2 New Troopers ! |
|
Back to top |
|
|
JP ***
Joined: 31 Dec 2006 Posts: 157 Location: Christchuch, NZ
|
Posted: Mon Jun 15, 2015 1:39 Post subject: |
|
|
Thanks for the clarrification, Gribble.
UPDATE: I've had the pump and injectors looked at by professionals. Injectors are about 90-95% of new injectors, and the diesel pump was shot - Timing was out a lot and the pump had some leaks etc.
Hopefully when I pick up Dan the boost issue will be resolved somewhat now the fuelling is back to factory spec. _________________ 93 3.1 LWB Auto |
|
Back to top |
|
|
JP ***
Joined: 31 Dec 2006 Posts: 157 Location: Christchuch, NZ
|
Posted: Mon Jun 15, 2015 1:42 Post subject: |
|
|
.......now to remove the cap covering the fuel screw _________________ 93 3.1 LWB Auto |
|
Back to top |
|
|
JP ***
Joined: 31 Dec 2006 Posts: 157 Location: Christchuch, NZ
|
Posted: Tue Jul 07, 2015 1:59 Post subject: |
|
|
Truck is back - injectors and pump rebuilt.
Now I'm stuck with 7-8psi max. I will be adding a 2.5" exhaust shortly and will look at getting the intercooler flushed to see if this helps with the boost. After that I will be looking at a boost controller - any suggestions? _________________ 93 3.1 LWB Auto |
|
Back to top |
|
|
yzfandy Newbie
Joined: 14 Jul 2015 Posts: 7 Location: Burnley
|
Posted: Wed Jul 15, 2015 7:19 Post subject: |
|
|
i am not really that clued up on tuning diesels but having owned a skyline for 4 years i have found the greddy profec b to be a good boost controller but it is a bit fiddley to set up. |
|
Back to top |
|
|
JP ***
Joined: 31 Dec 2006 Posts: 157 Location: Christchuch, NZ
|
Posted: Wed Jul 15, 2015 8:53 Post subject: |
|
|
I've gone with a Dawes Device manual controller _________________ 93 3.1 LWB Auto |
|
Back to top |
|
|
Rhanagar Lifetime member
Joined: 12 Jan 2010 Posts: 4861 Location: Preston, Lancs.
|
Posted: Wed Jul 15, 2015 12:51 Post subject: |
|
|
You have got an intact boost compensation line haven't you? _________________ 1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition
Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS
|
|
Back to top |
|
|
Rhanagar Lifetime member
Joined: 12 Jan 2010 Posts: 4861 Location: Preston, Lancs.
|
Posted: Wed Jul 15, 2015 12:53 Post subject: |
|
|
Also you have made sure the flap on the inlet to the intercooler isn't jammed shut. _________________ 1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition
Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS
|
|
Back to top |
|
|
|