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IainM ***
Joined: 08 Jul 2007 Posts: 135 Location: Durham
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Posted: Tue May 27, 2008 22:37 Post subject: Sluggish Engine Response |
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Hi,
I have noticed that my LC has seemed to be getting a little sluggish off the mark. I notice it mainly trying to pull into those gaps that don't exist on a busy roundabout in the rush hour.
Other than this, the motor pulls as strong as it always has.
I decided to try the auto stall test tonight to see what results I got. The manual says it should stall at about 1800rpm. Left foot hard on the brake, box in D, throttle wide open (only for a short time). No response times are quoted for the rpm rise time.
I found that the revs quickly rise to about 1400rpm, paused for what seemed like a second or two, then steadily climbed and stabilised out at about the correct 1800rpm figure.
Is the pause at around 1400rpm normal? Anybody else tried the same test and what results do you get?
Any other suggestions to improve the pick-up or confirm if something is not correct? _________________ 1993 VX 4.2TD UK Model |
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Posted: Tue May 27, 2008 22:37 Post subject: Google Ads keep this community free to join! |
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joinerman *******
Joined: 11 Sep 2005 Posts: 2200 Location: Here & there
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Posted: Tue May 27, 2008 22:41 Post subject: |
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Sounds like the fuel pump needs tweaking a bit.
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ciderman ***
Joined: 20 Jun 2006 Posts: 164 Location: back in derby for now
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Posted: Tue May 27, 2008 22:49 Post subject: |
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now it is funny you should say that mine 92 12v does the same it picks really slow and the mot test read 1.0% and 3.0% is the upper limit but mineis an import so has the altitude boost compensater on the pump (little set screw with lock nut on the diaphram dome) so looks like some tweeking needs to be done as in before and after mot settings _________________ my other toy has tits on |
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joinerman *******
Joined: 11 Sep 2005 Posts: 2200 Location: Here & there
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Posted: Tue May 27, 2008 22:57 Post subject: |
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As below
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Towpack *******
Joined: 10 May 2005 Posts: 1315 Location: Sheffield
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Posted: Tue May 27, 2008 22:57 Post subject: |
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ciderman wrote: |
now it is funny you should say that mine 92 12v does the same it picks really slow and the mot test read 1.0% and 3.0% is the upper limit but mineis an import so has the altitude boost compensater on the pump (little set screw with lock nut on the diaphram dome) so looks like some tweeking needs to be done as in before and after mot settings |
My UK car also has this screw adjuster.It's also called the off-boost injection volume compensator. _________________ Phil
1998 HDJ80 Amazon VX 4.2TD
2004 Yamaha R1 (Sold)
2011 Ducati 1198SP (Sold)
2012 kawasaki ZZr1400
2002 Honda XR650R (BRP)- STOLEN GRRRRR!!!
2010 Husaberg FE570....YIPPEEEEE!!!!
2003 GT XCR3000
1995 Border Collie-Passed away 23-5-2011 |
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joinerman *******
Joined: 11 Sep 2005 Posts: 2200 Location: Here & there
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Posted: Tue May 27, 2008 23:00 Post subject: |
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The other adjustment is the nut to the right & below the nut that says OUT there's plenty on here about it if you do a search
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Towpack *******
Joined: 10 May 2005 Posts: 1315 Location: Sheffield
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Posted: Tue May 27, 2008 23:32 Post subject: |
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joinerman wrote: |
The other adjustment is the nut to the right & below the nut that says OUT there's plenty on here about it if you do a search
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That's the main injection volume screw which governs the top end (and max revs) more than anything.The 1HD-FT also has another adjuster called the 'stock boost compensator characteristic tendancy' adjuster!! It's located by removing a hollow bolt just underneath and to the rear of the top diaphram housing.Not sure if the 1HD-T also has this.This governs the injection volume when the turbo kicks in at around 2K rpm.Using this + the main volume screw + the off boost adjuster the pump is quite tweekable.If you have an EGT & boost gauge you can play around and avoid going OTT and maybe damaging the engine.
1HD-FT pump _________________ Phil
1998 HDJ80 Amazon VX 4.2TD
2004 Yamaha R1 (Sold)
2011 Ducati 1198SP (Sold)
2012 kawasaki ZZr1400
2002 Honda XR650R (BRP)- STOLEN GRRRRR!!!
2010 Husaberg FE570....YIPPEEEEE!!!!
2003 GT XCR3000
1995 Border Collie-Passed away 23-5-2011 |
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IainM ***
Joined: 08 Jul 2007 Posts: 135 Location: Durham
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Posted: Wed May 28, 2008 17:41 Post subject: |
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Thanks for the comments
I tried the stall test a few more times now, in a bit more detail;
Revs rise to ~1400rpm quite fast,
slow and steady climb to about ~1600-1700rpm,
From 1600-1700 it seems to 'get the boost' and revs rise quite rapidly to 1800rpm where it stalls
So majority of time lag is from 1400 to 1600-1700 rpm
Total time to go from idle to 1800rpm stall has varied from ~5 seconds to ~10seconds
Before I start fiddling, i'd be grateful if others with a 12V auto could post results from the same test to get a trend going. Maybe this is normal??
If the 24V also stalls at around 1800rpm, maybe this would give some indication of the talked about difference in response time between 12V and 24V.
It's ideal if you are stuck in traffic and bored. Just keep your foot on the brake! _________________ 1993 VX 4.2TD UK Model |
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joinerman *******
Joined: 11 Sep 2005 Posts: 2200 Location: Here & there
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Posted: Wed May 28, 2008 19:52 Post subject: |
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Not something i'd want to do unnecessarily, puts a lot of strain on the torque convertor.
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IainM ***
Joined: 08 Jul 2007 Posts: 135 Location: Durham
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Posted: Wed May 28, 2008 20:41 Post subject: |
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Fair comment.
I suppose I am doing it unnecessarily - truck does everything I want and runs fine, just trying to understand if it is not quite right.
Not sure about excessive strain though. I wouldn't do it if I thought it would do any damage.
It is listed as a standard check in the Toyota service manual.
I thought that the applied torque was OK / acceptable but only to do this for a short duration to avoid excessive temperature rise. _________________ 1993 VX 4.2TD UK Model |
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Spanners ***
Joined: 20 Jan 2006 Posts: 150 Location: Stafford
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Posted: Wed May 28, 2008 23:11 Post subject: |
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Had my cruiser almost 9 years now. It has always been slow off the mark with noticeable turbo lag but then so have the two other 1HD-T engined vehicles I have driven. Some years ago I played around with the pump settings I also changed the injectors some time ago.No change. I just learned to live with the delay since in all other respects performance / economy is great.
However on a 15 year old automatic with 165K on the clock I would NOT undertake a stall test unless essential.
Cheers
Martin _________________ Landcruiser HDJ80 Auto 1993 |
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Towpack *******
Joined: 10 May 2005 Posts: 1315 Location: Sheffield
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Posted: Thu May 29, 2008 0:26 Post subject: |
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I reckon my 80 is quite quick off the mark for what it is,a 2.5 ton truck with @160hp.Compared to a hot hatch it's dog slow.Compared to my R1 it's practically nailed to the floor! Such comparisons are meaningless of course.Everything is relative.I accept the LC for what it is.It's strength is it's torque and the way it delivers it. _________________ Phil
1998 HDJ80 Amazon VX 4.2TD
2004 Yamaha R1 (Sold)
2011 Ducati 1198SP (Sold)
2012 kawasaki ZZr1400
2002 Honda XR650R (BRP)- STOLEN GRRRRR!!!
2010 Husaberg FE570....YIPPEEEEE!!!!
2003 GT XCR3000
1995 Border Collie-Passed away 23-5-2011 |
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IainM ***
Joined: 08 Jul 2007 Posts: 135 Location: Durham
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Posted: Thu May 29, 2008 22:10 Post subject: |
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Thanks for the comments.
We've had this truck since new and I wish I'd done this test when it was newish so I had some solid data to compare against.
What would be different due to age that would make the test risky?
Compared to new, lower capacity, common rail diesel trucks I've tried I would say the the low rpm performance is poor (for similar peak horsepower and truck weight), but I quite like having a robust mechanical injection motor and for now paying relatively low road tax!
I'm pretty sure the gaps in roundabouts in the rush hour were much bigger 15years ago, so maybe it just feels like it's got slower over the years as the traffic around is accelerating quicker!
The biggest problem for me is trying to pull out into a busy road with a heavy trailer - this is where the lack of low rpm torque (lag) really shows and in busy traffic using low ratio to boost torque at the wheels is just a non starter.
No fiddling for fiddlings sake with pump settings, so I'll leave alone.
Cheers _________________ 1993 VX 4.2TD UK Model |
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ih895 **
Joined: 24 Feb 2007 Posts: 114 Location: S Essex
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Posted: Thu May 29, 2008 22:20 Post subject: |
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My 95 24V has poor pull below about 1800 and next to nothing under 1200. Our previous 12V had loads more low down torque. I also have found this a pain in the a** when pulling a laden trailer. I have not been inclined to fiddle either but has anyone improved performance and what are the consequences on fuel consumption. It pulls OK at 2000+. |
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Towpack *******
Joined: 10 May 2005 Posts: 1315 Location: Sheffield
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Posted: Thu May 29, 2008 22:29 Post subject: |
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ih895 wrote: |
My 95 24V has poor pull below about 1800 and next to nothing under 1200. Our previous 12V had loads more low down torque. I also have found this a pain in the a** when pulling a laden trailer. I have not been inclined to fiddle either but has anyone improved performance and what are the consequences on fuel consumption. It pulls OK at 2000+. |
Click on the link in my post above.The tweeks work. _________________ Phil
1998 HDJ80 Amazon VX 4.2TD
2004 Yamaha R1 (Sold)
2011 Ducati 1198SP (Sold)
2012 kawasaki ZZr1400
2002 Honda XR650R (BRP)- STOLEN GRRRRR!!!
2010 Husaberg FE570....YIPPEEEEE!!!!
2003 GT XCR3000
1995 Border Collie-Passed away 23-5-2011 |
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