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DavidW
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Posts posted by DavidW
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I've been running the Britpart plastic ended 19J type rad with built in oil cooler with my 3.9 v8 for a few years and it hasn't failed yet.
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On 12/17/2007 at 2:24 PM, Bull Bar Cowboy said:
Close Loop Idle Valve
For me the inclusion of a valve was going to serve two purposes……..
1. Provide a fast idle with a linear degradation to operating temperature.
2. It seemed good idea that if I could get it to work in closed loop mode then in some off road situations it would allow me to idle over obstacles without intervention of the throttle……..
The valves work by applying a PWM (Pulse width Modulation) signal to the solenoid coil of the valve ………….. the true DC (volts) value will depend upon the length of the pulses applied …………… therefore this gives an infinitely variable voltage between 0V and the vehicle max volts (14V). These valves come in two flavours……… rotary or plunger………. the solenoid coils also come in two flavours……… single coil where the valve has a sprung return, or dual coil….. one coil to open and one coil to close.
I opted to use a single coil sprung return rotary valve …………. Taken from a Volvo 940 2.3L turbo . The valve itself has 20mm inlet and the ability of move a large amount of air…..
Installation is easy………. throw away the plenum stepper motor and replace with a blanking plug (thanks HFH) and then plumb the valve between the throttle body air outlet and the plenum EAV inlet. If the valve is mounted just behind the plenum then the valve to plenum pipe can be ETC6370 and the throttle body air outlet to valve can be the same pipe from the Volvo 940.
These valves work in the following sequence ………… @ 0V the valve is slightly open…..@ low volts the valve is closed……..@ low volts and increasing volts opens the valve. The reason for this is if there is an ECU or wiring fault then the default value is a fast idle.
Most documentation about these valves show @0V slightly open …….@ 25% duty cycle, valve closed ………@ 40% duty cycle, normal operating area….
Bench testing the valve on a variable power supply showed this to be true …….. circa 3.5V and valve was closed and it began to open as the volts were increased to around 4V………….so, as 3.5V is 25% of 14V then the 25% duty cycle rule is correct.
You may think this is a lot of faffing around …………. but its important later.
Here I will detail my errors (that cause a lot of head scratching), because I know that others will encounter the same issues.
With the valve plumbed in and unpowered the idle was about 1800 rpm ……….. I decided that was a bit high and reduced that the 1200 rpm by closing the throttle stop a little ………. WRONG ……… but more about this later………
With the valve connected and following the MS (idle valve) tuning info I got a really good and stable idle using the following settings………
One of the reasons for using 100 (arbitrary number to set the frequency) as the PWM frequency is that the duty cycle is only true at 100 and that it gives the valve 1% resolution. At higher or lower frequencies you need to calculate the duty cycle.
DUTY CYCLE% = Lower or Upper dc * 100 / Idle Valve Frequency value
The test of idle stability was to quickly turn on and off the heater and 750Watts of lights…… the idle would take a slight dip from 850 rpm and very, very quickly return to 850rpm ………….
With Meagtune, its best to set up an “idleDC” gauge so that the operation of the valve in terms of % duty cycle can be clearly seen. The operation was very clear……… with no engine load it was running @42% - 44% DC ………. by loading the engine the valve was opening to 58% DC……….. on open throttle it was closing to 25% DC …………..
The only real problem at this stage was the ‘settle’ time from an engine start……. However, the first test drive produced another issue ………. after a decent overrun (say coming up the standing traffic or lights) the idle would dip and an engine stall would occur before the idle control had chance to recover…………..not good…
After a bit of lateral thinking ………… idle control systems must have to rely on a good base idle as the mechanics of the valve would not allow huge quick changes in open/cloe to find the correct idle valve ……….. in this respect a stepper motor would probably perform better and the changes could be more precise, but, without a base idle reference the performance would be far from perfect.
So … to set the base idle I used the following procedure ………… disconnect he valve from the plenum and blank the plenum air inlet. Then set the base idle (using the throttle body butterfly stop) to a value that is just below the required controlled idle ……… I set mine to 800 rpm as I wanted a controlled 850rpm……
Reconnecting the valve and test driving, confirmed that the stalling issue was resolved and the idle was perfectly stable @850rpm………….
The next issue was the settle time from an engine start ………
Even on a hot engine the valve was taking too long to settle, thus giving an oscillating idle for maybe 10 or 20 seconds immediate after an engine start…………….once settled the operation was fine.
If the first start sequence is carefully watched ………… the valve opens to the cranking duty cycle, then closes to the ‘closed value’ as the engine fires & runs (provided the throttle is open….which it will be) and then as the throttle is released, it goes back to the cranking duty cycle value and steps down from that to try and find the correct idle………
Where as …………. Once the engine has been started and idle has been found, then following that point the software uses the minimum duty cycle setting to find the correct idle value …………. big difference
So ………….. to over come the start issue I tried setting the cranking value to be much closer to the minimum value ……….. in that way the valve has a much smaller operating range in which to find the correct value ……… as the operating value is 42% - 44% (@ normal operating temperature) and the minimum is set at 40% …………… setting the cranking value to 45% means the valve only has a small window in which to ‘find’ the correct idle. On a cold start the value opens up to 52% (dependant upon IAT).
This setting has now completely cured the start up issues on both warm and cold starts………….
megatune shots..................Warm engine
Cold Engine................
It seemed to me that the engine / software responds better to the valve opening, rather than closing from a high open value …………. I guess that makes good sense if you think about.
Its not absolutely 100% perfect to my liking (probably about 98% perfect) as there is a very slight overshoot on load variation ………… I can see it because I am looking for it, but I guess it wouldn’t be noticeable to anybody else driving the truck. However, I am reasonably sure that this can be resolved with a little bit of fine tuning of the settings.
The final test was to go up the farm and see how it performed in low range 3rd without any throttle input ………….. it behaves just like a diesel driven in the same manner, only maybe a little more controlled ………..it took a very steep slope to stall the engine and literally walks over obstacles that would have need to have been ’driven’ previously.
Have fun !
Ian
I don’t suppose anyone has the images from this post? I’m struggling get get my valve and idle working nicely.
Alternatively, can anyone share their settings. I have a standard 3.9 with Nige’s kit bolted on.
Thanks
David
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21 hours ago, western said:
I fitted 2 -2 jet front screen units to my 110, moved the original to the right hole [rubber bung in it normally] & got a 2nd to fit to the left side, existing pump has more than enough power to apply 4 jets of fluid to my screen even at motorway speeds.
I've also done this. It's like having a normal car!
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Dailysleaze, thanks for posting the photos.
It would be good if these could somehow get linked back the technical archive post to make that thread useful again?
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Does anyone know where I might find a copy of the how to photos missing from this thread?
Thanks
David
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3 minutes ago, Bowie69 said:
A supplier name may help the OP
Fair point....
This is the one I bought
The seller is called autosiliconehoses_outlet
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Hopefully the attached photo will work and show how I've just got around a similar problem.
The bend after the the manifold is a reducer from Ebay for about £20. The supplier seems to have pretty much every combination going.
All the best.
David
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I had a single with a 200tdi but have swapped to a double fan for the v8 as it probably moves more air and actually seems to be shallower in the engine bay.
My Ebay Ebay link didn't work but they are mark 3 mondeos. Just cut the legs off and they fit well.
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I've installed the seat box ends and battery box from YRM on my 90.
I think it helps to do one end at a time to stop the whole thing going floppy.
I did the joints with sikaflex and rivets so it's strong and waterproof.
Overall it's a great repair/mod and I simply don't understand why they didn't make them like this to start with.
D,
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I've used the fan from a Ford Mondeo for years and they've always been reliable.
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I've spent a lot there while rebuilding my 90 and generally prices and delivery and great.
It's just when you have a problem or need a return a part it all goes wrong.
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I've been trying to do contact them for weeks about a return. Very poor.
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Are they just the side pieces, or is the complete outer wing available in abs?
They are the the side outer skins.
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I've got some from Paddocks.
The holes took a bit of tweaking to fit my 1986 wings but they are now painted and look great.
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My galvanised bulkhead has holes as you mention at the bottom of the a pillars. In theory it will be galvanised inside although I filled the hole up with sikaflex before sticking the gasket down.
David
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The way these seem to be appreciating, I'd go original.
Wish i had one....
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My D3 is insured through Tesco. I've not claimed from them yet so have no idea how them will perform.
They couldn't cope with the Defender due to it being non standard so that is insured with Flux.
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So when I build up my new doors, do I need to get some of these wedges?
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I'm just jealous of your v8 brackets!
Where did you find them?
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I bought an L reg 3.9i for the engine.
It was too good to break really...
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I asked them about the price increase when I ordered - they said it was down to a supplier raising its price.
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I've just had two of the galv doors from SP delivered. They're not painted yet but look good quality.
Looks like I will need to make a bracket to hold the bottom of the winder mechanism which is a bit annoying but given the price compared to second hand on eBay and the fact that they will last, they seem good to me.
Service from SP was good.
David
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I think that the V8 early defenders (if standard) will become the 90 to have/become collectors items. If your going to pay a fortune in the futore to own a 90/defender, which would you choose? It would be a V8 every time for me - provided it's a secondvehicle and limited milage.T
They can only go up in value
This is already happening. I've a friend who has just bought one and we've been watching the values.
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Has the OP done this yet? - I'm interested to know how it went!
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Land Rover defender 3.9 v8 radiator with oil cooler
in Defender Forum (1983 - 2016)
Posted
I've done this. It works fine.