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Bull Bar Cowboy
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Ok………. Although the MS forums are very good, they seemed to be aimed mainly at the fast street car / race motors …………. We tend to drive ours a little differently ……… :rolleyes:

I think that there are enough of us on here now with MS to have decent discussion about issues which relate the use of our trucks.

My biggest problem is heatsoak into the IAT sensor <_< …………. it causes the the engine to hunt badly at tickover ………… checking the IAT shows 41C :blink: , so I guess its trying to lean it out. Disconnecting the sensor brings me back to an excellent stable idle. Trouble is, that the under bonnet temps of a decent V8 are bloody hot, so avoiding heat soak will be a massive problem. I am considering dispensing with the IAT sensor altogether and just fitting a resistor to make it think the air temp is always 15C – 20C

The other issue that has been nagging my poor brain …………….. if the manifold depression is say 45Kpa at idle, then why do we need mapped fuel for 15 or 20 Kpa (some have even rows in there)…….. I can understand putting in may be one row below 45 Kpa (say 30Kpa), but the rest are redundant as the engine will never see those bins. The extras rows would be better used in the higher Kpa range thus almost giving more resolution to the map.

So come guys, lets be having some views on these anomalies ………….. B)

:)

Ian

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Being a Trainee Tart I thought I would have a better heat dumper than steel and go for Stainless, so hence the pipe in 316

Whilst that does seem better, the TIG welding then required meant I had to start stalking Tonk and Jez for a grown up job on it :lol:

While I have driven mine about I can get mine well under 45KPA, mainly on overrun / bascking off - does this mean fuel has then also been cut off in the settings

and also I can get it to do it when engine is 'overstretched' - ie wrong RPM gear foot not on throttle, but its only there for a short time....

Nige

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Get a 300Tdi - no heat soak and no IAT sensor :P:lol::ph34r:

mmmm...diesel.... good for taxi's and tractors ..... did you know Rudolf Diesel invented the diesel engine? The following extract from Wikipedia perhaps sums it up...............

Diesel was something of an unstable character, having several nervous breakdowns, and was somewhat paranoid at times. He defended his priority of invention tenaciously. Diesel toured the United States as a lecturer in 1904, and he self-published a two volume work on his social philosophy.

On September 29, 1913, while in Antwerp, Diesel boarded the SS Dresden ferry to cross the North Sea. The next morning, the steward discovered that Diesel's cabin was empty. Diesel's body was found in the Scheldt river on October 18.

One theory in Diesel's death is that he died by suicide, possibly due to being deeply in debt. His family stated that he committed suicide because his invention was stolen and a cross in his journal on the date he died indicates suicide. Also, a briefcase containing a very small sum of money and a large amount of debt-ridden bank statements was left to his wife, Martha.

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Ok………. Although the MS forums are very good, they seemed to be aimed mainly at the fast street car / race motors …………. We tend to drive ours a little differently ……… :rolleyes:

I think that there are enough of us on here now with MS to have decent discussion about issues which relate the use of our trucks.

My biggest problem is heatsoak into the IAT sensor <_< …………. it causes the the engine to hunt badly at tickover ………… checking the IAT shows 41C :blink: , so I guess its trying to lean it out. Disconnecting the sensor brings me back to an excellent stable idle. Trouble is, that the under bonnet temps of a decent V8 are bloody hot, so avoiding heat soak will be a massive problem. I am considering dispensing with the IAT sensor altogether and just fitting a resistor to make it think the air temp is always 15C – 20C

The other issue that has been nagging my poor brain …………….. if the manifold depression is say 45Kpa at idle, then why do we need mapped fuel for 15 or 20 Kpa (some have even rows in there)…….. I can understand putting in may be one row below 45 Kpa (say 30Kpa), but the rest are redundant as the engine will never see those bins. The extras rows would be better used in the higher Kpa range thus almost giving more resolution to the map.

So come guys, lets be having some views on these anomalies ………….. B)

:)

Ian

Re heatsoak, I moved mine from being more or less in the plenum, to a plastic pipe on the side (flapper type cold start extra air pipe) settled the tickover rpm instantly, so assume little heat soak with reasonable reading.

I really cant see putting a resistor in line would cause any problems at all during normal running, but is this temp considered on cold start settings during warm up? Or does the MS ignore untill warm up markers have been reached? Potential for weak cold starts on the winter morns?

After our telephone conv today, I double checked my Kpa, on a tickover of 600rpm Im at 41Kpa, so better than I remembered.

My current project is to get to atmospheric press. during WOT, Im nowhere near at the moment, double plenum here I come!

Get a 300Tdi - no heat soak and no IAT sensor :P:lol::ph34r:

And of course - No throttle response :ph34r:

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Heat soak - not caused me a noticeable problem yet. My IAT on the RR is cable-tied to the mouth of the air filter :rolleyes: the 109 it's in the 9th injector hole, whilst it does read hot sometimes it's never noticeably given any issues. We'll see how it does off-road I guess. You could always make the IAT settings less aggressive.

The stuff down to 15kpa or so is engine braking/over-run, so IMHO worth keeping on an off-roader or even expanding as you can tweak it for better hill descent. Top Secret Dave was talking about using that area of the ignition map to give very aggressive engine braking, putting a big advance number in to almost slow the piston down as it's rising towards TDC - potentially a risky one to get right but could be very effective.

Similarly, tricks like that in the area around & below idle can give very aggressive idle stabilisation for those running winches - either electric or engine-driven.

The "loss" of the space on the table doesn't really bother me, MS interpolates the values anyway so I'm more than happy with 12x12. I think MS-II will give you huge table resolution if you so desire.

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I've not had a much of a problem problem with heatsoak either, my IAT is tapped into the the plenum, just upstream of the butterfly (in heinsight it was a bit of a bodge job to get it running). The idle is fairly stable but can go lean when hot starting. I've got a GM IAT sensor and sealed connector (from diyautotune) and will be fitting this into an aluminium link pipe as part of the feed from the raised air intake.

Incidentally, the water jacket stuck to the bottom of the intake on the plenum.. im guessing it's there to stop the throttle plate freezing up in cold weather but do we need it in the UK climate?

Ian - How much is your IAT fluctuating (celcius wise) to cause the hunting? mine changes slowly

I think you can change the MAP values against each row of the VE table to give more resolution at the high KPA values (but think you'll need to re-tune VE after doing this)

I did have a problem with the engine bogging when deaccelaring back to idle after blipping the throttle in neutral, turned out those 20kpa bins had very low values, MS interpolates / averages values from upto 4 nearby bins to get the fuelling values. If you do this while recording a log then play it back through a new version of MegaLogViewer you'll see it in action.

Tickover on mine is 850 rpm and about 35 kpa.

Also, WOT at any RPM sees at worse 2 to 3 KPA less than atmospheric pressure, i don't run an airbox or conventional filter, 70mm pipe from plenum straight up to snorkel which has a K&N & prefilter thing stuck on top.

(whats with the restrictive cone shaped inlet on the Range Rover Classic airbox? :unsure: )

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Incidentally, the water jacket stuck to the bottom of the intake on the plenum.. im guessing it's there to stop the throttle plate freezing up in cold weather but do we need it in the UK climate?

Mine isn't connected and seems no worse for it. Two less pipes to worry about :P

I think you can change the MAP values against each row of the VE table to give more resolution at the high KPA values (but think you'll need to re-tune VE after doing this)

You can change the RPM bins and the MAP bins, there is probably something out there to re-scale your fuel map to fit, have a look on the MS website.

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Wow ………………….this is all good stuff …………… Apart form El boggo in the Islas Malvinas :ph34r: ............ who I seem to remember has a V8 discofairy as well as the 300 fat fryer 90 :rolleyes: ……………..that’s because every now and again he needs to drive a real truck to get away from tractors and other agricultural land rovers………………… :lol:

IAT …………………. Having checked the calibration, mine is fine at start up and reading correctly. Heatsoak only occurs when I have been stationary, or slow moving for a while……………..it just slowly increases temperature, usually to between 30 and 40C…………………. but once I start moving on the open road again the temperature soon comes back to normal within a mile or two, however, slow moving off road and the temperature is reluctant to come down.

Currently the IAT is mounted on a short steel link pipe from the air filter to the samco hoses. Its position is at the rear of the engine against the bulkhead. Having had a probe around, I might well use the air box as the next location as this does seem a lot cooler.

Having read the MS forum extensively on this subject, and also looked at the calcs, it does seem that MS performs quite an aggressive calculation for the pulse width in conjunction with the IAT input (one of many).

Manifold Depression …………………. Yesterday in order to see certain tuning parameters, I gave mine a quick burst of WOT for a few seconds ( from the logs, 9 to be precise)………………. and I get atmospheric @ 99Kpa………………… also it goes frightenly well……… B)

Going back to the fuelling below idle Kpa …………….. if idle is 45Kpa then anything below that will be a closed throttle, and I guess that all of us will be running with fuel cutoff (after 1 second) enabled to give better engine braking……………. I might try a map with just one line (say at 30kpa) to see what happens.

Manifold depression at idle is dependant upon the state of tune …………. long before all the handy electronics we have today, I used to tune my A series race engines by firstly swinging the dizzy at idle to give max depression (this sets the ideal static)……… then set up the carbs to give max depression ………..the actual numbers depend upon a lot of factors ………. mainly cam overlap, fuel / air ratio, & timing……………..

A good example is yesterdays first startup on the rebuilt engine ………….. the idle was sh!t even with the butterfly gap set at 8 thou. A quick check showed the manifold depression to be 58 to 60Kpa and the WB O2 sensor was reporting an AFR of almost 19:1 ……………… bringing the AFR back to 14.5:1 increased the depression to 46Kpa ……… further fine adjustment of the spark map has now got the depression to 43 Kpa, a number that I am very happy with as the cam is not exactly standard.

:)

Ian

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Wow ………………….this is all good stuff …………… Apart form El boggo in the Malivno’s :ph34r: ............ who I seem to remember has a V8 discofairy as well as the 300 fat fryer 90 :rolleyes: ……………..that’s because every now and again he needs to drive a real truck to get away from tractors and other agricultural land rovers………………… :lol:

It was tongue in cheek cos I love my V8 as much as the next man :)

Where is the "Malivnos"? :unsure:

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Stephen .................. you seem to have spelt it wrong :rolleyes: ..................... my post spelt it correctly ;) .................... I understood that the Islas Malvinas were those little bits of rock in the south Altlantic owned by the UK .......... strongly contested by Argentina, and now the subject of proposed ownership by Venezuela :rolleyes:

Yes, I know to well enough to understand your humor :P .... sorry if my post seemed a little scathing and aggressive . :unsure: ........... I wasn't meant that way..... ;)

:)

Ian

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Stephen .................. you seem to have spelt it wrong :rolleyes: ..................... my post spelt it correctly ;) .................... I understood that the Islas Malvinas were those little bits of rock in the south Altlantic owned by the UK .......... strongly contested by Argentina, and now the subject of proposed ownership by Venezuela :rolleyes:

Ah the joys of editing posts :)

Now where is the Altlantic? :P

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After lots of careful measurements today the ‘after a run’ & very slow moving heat soak is mainly caused by the engine heating the air in the intake system, rather then general heat of the pipework ………….obviously this is much worse when stationary after a run ……. I guess the hot air is trying to rise so is eventually expelled from the snorkel.................. so I guess its no going to be possible to eliminate the heatsoak completely ........

Different sensor positions give very different results ……… I have found the best place to be in the inlet end of the air filter box………… here, once the engine is running, it seems to cool very quickly.

:)

Ian

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