Jump to content

** MegaSquirting a V8 - "Basics of How to" ... The A-Z Saga


Recommended Posts

Need to have a good study of it but 1st lokos are

1 - The CTS is always below the threshold of 72 degrees, this means it is always on WUE - ie choke always on, engine is not getting hot enough

most likley thermostat issue ?

2 - TPS doesn't seem to give full rnage - but unsure what the log represents until I have a good look

3- MAT also on the cools ide ? will not help, could just be a cool day

Will look more when I get a chance

Others will I'm sure look too, and prob beat me to it !

:)

Nige

Link to comment
Share on other sites

Aside from Nige's points and a couple of glitches (@644 secs for example) I can't see much wrong with that. How was it behaving when you did that log?

O2 is always zero, presumably because of the problem with the sensor, but EGOCORR (correction based on O2) stays at 100% (open-loop), presumably because of always being too cold for it:

ego_control.png

For the time being (dead O2 sensor) you may as well leave O2 correction disabled (authority 0%) or it'll wander off into the weeds.

There are three thresholds for engine temperature:

- Warmup enrichment (WUE) which knocks off once the temperature goes past the last cell in the warmup table

- Fast idle, which switches off (if you're not using PWM / closed-loop) at a set temperature (engine constants 1)

- O2 threshold, as seen above, which is often higher than the end of warmup.

Link to comment
Share on other sites

The log was done after the land rover was parked for 2-3 hours so water temp wouldn't have been right down, it was after 8pm in the evening so the air temp would have been cool and was slightly raining.

The temp on the dash rose and held at operting temp and the guage on megatune was showing in the 80's, the temp rises quickly then maintains so I would be surprised if the stat wasn't operating properly I am surprised the datalog shows the temp so low.

The landy sounds fine at idle except for a bit lumpy. when it is cold it sounds as though it has a slight knock at idle but smoother, when warm this knock goes and is more lumpy.

when cruising at constant throttle ok.

when you go on or off throttle you have this trough in rpm when it goes down then backup and it will then splutter and cough at the bottom of the trough (it is almost as though you loose 1/2 the cylinders), if you are too savage with the throttle it will try to stall, this is there all the time but more noticable/worse when it is cold. You cannot pick the revs up from idle without this dip in rpm and it stumbling. This can be quite frightening as you start to pull out of a junction and it tries to stop, or you are in the middle of the junction without any power. Also when in traffic it is spluttering and buggering about as you crack the throttle just open to ease it along as you are not able to hold the throttle in one position due to the low speed.

You cannot start the landy from cold without it starting then stopping, 2nd time start then revs drop stumble then stall or pick backup and away she goes,it will stall 2-3 times from cold depending on how cold it is, leave to warm up a few seconds then rev it a couple of times through the stumble area to help with the dip in revs then off you go. When warm starts everytime doesn't stall.

The datalog shoulld have the 02 sensor switched off as it wasn't working which is how I have been running prior to the o2 sensor being added, interesting it is showing 0volts for the 02 sensor in the log when it is displaying this residual volts on the guage.

My helper isn't coming today now and as it is torrential rain here it isn't going to get looked at today, will have to be later in the week when the weather is better. But suggestions on what to do and what to look at then greatfully received.

Glenn

Link to comment
Share on other sites

Think I've spotted something:

At time 315 seconds(ish), the MAP is coming up, presumably because you have pressed the throttle. However, TP is still at zero. The revs at this point dip to 600 ish.

It is in fact unusual for the TP to read zero at all - at idle, normally it sits around 10-15% = 30 something in raw form I think.

Take a peek at your TP sensor: With the engine switched off, but ignition on, you should have a reading above zero on the megatune gauge. This should vary to near 100% with foot flat on floor. It doesn't matter if it doesn't get all the way there, but definitely over 90%.

Adjust it to achieve the above - I think it's loosen two screws then rotate it relative to the throttle spindle.

Edit: You got there first. This would account for your spluttering throttle when you use your right foot. It'll play havoc with the acceleration enrichment.

Link to comment
Share on other sites

Ok, I'll add a little more in response to your post above:

The MAT looks fine. It starts below 20, but rises to 30 something by the end of the log. This is pretty consistent with what you'd expect on a cold damp day. It is plenty close enough anyway.

As for coolant temperature - this log was taken without any load. I wouldn't expect it to get hot very quickly when idling away. Providing it gets to full temperature when you are driving this, we can discount this for the time being. There might be a thermostat problem - but that isn't the source of the problems you are describing.

Link to comment
Share on other sites

  • 3 weeks later...
  • 4 months later...

Hello all!

What an Impressive thread! Thanks for all the good info by all on this site. It gives me inspiration to start my conversion. I feel confident between all the great info here, the diagrams shown, the logs and programing shared and the manual I should have no problem getting mine to run. But at least I know where you are when it doesn't... :D Thanks again all!

Eric

Link to comment
Share on other sites

  • 4 weeks later...

Greetings from the south pacific everyone !

I am taking my time, but I am gathering the most possible parts and informations before jumping in the megasquirt 1 & EDIS world :-)

I have read the saga thread which is really interesting, and quite a few others, but I have yet a few questions for the MS experienced users :

1°) VE and timing maps wise, are there some adjustments more sensible/specific if the standard 3.9 is with an autobox rather than a manual ?

I remember in a thread someone asking for a map, and Nige asking if manual or auto ?

I would be very gratefull if someone could send me pics of both maps with req_fuel and/or a MS1 029v with EDIS msq for a standard 3.9 with AUTOBOX then, or tell me what I should take care when adjusting maps if with an autobox.

2°) It was very interesting to read Ian and Nige explanations on their PWM closed loop idle.

With autobox, A/C and a winch, closed loop idle is definitely needed I think.

Now, I am missing a few things.

- as these informations are now close to 4 years old, Ian's post #180 / #186 are missing the posted images, so we do not know the settings used to try understand and compare with Nige's pwm post #221.

If someone have them at hand somewhere, it would be great .

- in the same idea, after nearly 4 years using pwm idle closed loop settings, Ian, Nige and others, how is it going ?

Have you tweaked the settings more than in the posts above ?

With nowadays knowledge, what would be your recommended settings for PWM closed loop idle for a standard 3.9 with AUTOBOX ?

and what is your updated understanding of the related PWM CLI settings and their effects ?

3°) I have no ability to do welding on the manifold, so I have made a little bracket out of aluminium angle, and plan to mount the IAT sensor on this inside the square type airbox, above the air filter, just at the mouth of the output of the airbox.

Doing this will be quite easy for my skills, I hope this will also save me a bit of heatsoak, and it will measure the air which is indeed leaving the airbox to enter the old AFM and the engine. SHouldn't be too wrong ?

(oh, and the Wire output form the airbox will be done with a PG7 waterproof gland.)

What you guys think of this idea ?

4°) In a near future, I plan to add a snorkel also... do you think it would affect the tuning ? If so, maybe would it be a good idea to install the snorkel before tuning ??

Sorry for all these questions, and thank you in advance for your help.

I will not have anyone around me here to get a help on all that, so your feedbacks will be a must !

I hesitated to open a new thread just for asking these questions and decided to add my post here. If not the correct thread, I am sorry.

Cheers

Erik.

Willing to megasquirt a V8 in New Caledonia :-)

Link to comment
Share on other sites

  • 3 weeks later...

1) VE and timing maps wise, are there some adjustments more sensible/specific if the standard 3.9 is with an autobox rather than a manual ?

I remember in a thread someone asking for a map, and Nige asking if manual or auto ?

I think there are suitable maps posted for most engines, to be honest any of them will get you up & running and then the (fine) tuning process is down to you & your engine.

2) Ian's post #180 / #186 are missing the posted images, so we do not know the settings used to try understand and compare with Nige's pwm post #221.

Sorry I can't help with that one.

3) What you guys think of this idea ?

Sounds fine to me, IAT measurement is not too critical.

4) In a near future, I plan to add a snorkel also... do you think it would affect the tuning ? If so, maybe would it be a good idea to install the snorkel before tuning ??

I don't think it makes a big difference.

Link to comment
Share on other sites

Hi Erik.

2°) It was very interesting to read Ian and Nige explanations on their PWM closed loop idle.

With autobox, A/C and a winch, closed loop idle is definitely needed I think

I have Nige's setting some where but you might be better using the PWM valve just for warm up on an auto as you might have trouble stopping the PWM trying to give you a flying start when you put it in gear.

Jeff

Link to comment
Share on other sites

I have Nige's setting some where but you might be better using the PWM valve just for warm up on an auto as you might have trouble stopping the PWM trying to give you a flying start when you put it in gear.

Could you post these settings here please, Jeff?

I'm about to start converting my RRC from carbs to MS and would love to try the closed loop idle control.

Link to comment
Share on other sites

Could you post these settings here please, Jeff?

I'm about to start converting my RRC from carbs to MS and would love to try the closed loop idle control.

Rob, these are my settings but mine is a manual. You could try these and see how it works.

PWMsettings.jpg

Jeff

Link to comment
Share on other sites

Hi Jeff,

thanks again for your feedback on the PWM closed loop idle matter. I understand what you mean.

When the autobox engage in drive, the rpm will drop, and then closed loop will rise them...

Anyone around here running closed loop idle with an autobox could jump in with his experience and if successfull, settings to fiddle with in PWM closed loop idle to be compatible with the autobox specific way of life :-)

Deadband maybe ?

Thanks again

Erik.

Link to comment
Share on other sites

Erik,

Actually the differences between a Manual and a Auto are minimal on PWM settings to maintain a solid tickover.

The key thing to remember is the TPS Setting, ie the accellerator movement - often measures

between say 10 as low and say 300ish as high.

You MUST calibrate the TPS for the PWM to be accurate, this way you then set the tps 10 units

above as a start the lowest value it holds, then start the engine and when warm, right click

on Megatune and select the TPS Gauage, this will show you where the throttle is when warmed up

and in neutrail and running at the right RPM, the TPS value that it shows should be HIGHER tahn

in the PWM settings - TPS threshold,In simple terms the PWM will only work if the TPS THreshiold

in the PWM settings is higher than what the TPS is reading in Megatune, if the actual value

is lower than TPS Threshold then PWM is switched off.

Once you have the 2 vlaues with the engine running warmed up in neutral, engage drive and see what

happens, sometimes the TPS moves, if it drops and switches PWM off (which it

does for some odd reason on autoboxes enageing but only sometimes) you'll have all sorts

of issues. again make sure than even though the revs drop, and prob then raise again the

TPS on the ecu is higher than actual.

This way the PWM will work when warmed up both in neureal and in drive.

See how this then runs and report back, too many tweaks in other boxes will just have you

ending up confused and probably running worse, with the setting process above I have found

I have sorted out many tickover probs, what Jeff is using may be one on my older base

settings, which he has then over time tweaked here and there to suit his engine and

requirments, mine on my daft 4.5 JED V8 are only a few numbers here and there different - ie

startup I hold for 250, and cranking I have at 94 ! other than that the numbers are dmaned

similar, as at the end of the day we are all running V8 Rovers of one sort or another

Hope this helps

Nige

Link to comment
Share on other sites

Hi Nigel :-)

thanks for your feedback and knowledge.

Sorry to repeat differently what you said, but this is just for me to try and see if I understand your explanations... as I am not a native english speaker and I might have misunderstood something.

Ok, so we need to be very carreful about the TPS calibration.

When idling, right foot off, TPS calibrated, I should look for the lowest TPS value read in realtime in megatune, engine warm, in neutral and also with gear engaged.

(in theory should be the same, as no one is touching the throttle... but your trustfull field experience shows this could happen not to be true)

Then the TPS threshold should be set about 10 pts higher than that for a start.

As I understand that the closed loop is only active if the real TPS value in realtime (with other conditions) gets below the TPS threshold set in PWM closed loop settings.

So for some reason, engaging drive on an auto might make the TPS move up (?) then de-activate the closed loop if moving higher than set threshold ...

Am I right in thinking that ?

Many thanks again

Cheers

Erik.

Link to comment
Share on other sites

So for some reason, engaging drive on an auto might make the TPS move up (?) then de-activate the closed loop if moving higher than set threshold ...

This bit sounds wrong, the TPS figure is taken directly from the sensor on the throttle butterfly, and is therefore ONLY linked to the throttle pedal position, the fact there is an auto box behind it makes no difference at all, it cannot interfere with the TPS reading.

Engaging drive in an auto will of course increase the load on the engine, and this is what takes the time to get right, after a LOT of tweaking I am still not really happy with mine, which is a shame :( The problem comes when you are trying to provide a reponse to a change in RPM in various different conditions, all of which have a different natural frequency which you need to try an iron out.

The 4 different situations are:

  1. Cold start
  2. Warm start
  3. Cold running after ASE has finished
  4. Warm running

This can then be doubled to 8 when in N/P or in D, as each has a different natural frequency.

This makes tuning it very difficult, you can get it perfect when warm running but have it hunting all over the place when warming up, or after a restart for example. My advice would be to get it operating on warm up only, get it right and then take a backup of the settings. Then once you have this, try tinkering with the closed loop stuff, and waste hours(!)

Calibrating the TPS is easier than you seem to make it sound, in Megatune, just go to Tools -> Calibrate TPS, lift foot off the pedal, hit get current for closed, then mash foot down, hit get current for full throttle. Job done.

Hope that helps somewhat :)

Pete.

Link to comment
Share on other sites

Pete

Your right - it shouldn't, but what I think happens on some is the autobox

"Clunks" in drive, and the shock makes the butterfly open a tad, which moves the TPS

up a bit

Normally this happens so quick its not noticed, but, if the "Clunk" moves the butterfly / VE / Spark

cells slightly - and then the TPS moves out of range, the PWM switches off.

Then the engine has no PWM Control, and the engine changes RPM/Spark?VE trying to settle, when the

engine rpm / tps drops again low enough then PWM Control switches itself back on and moves

the settings again and so on.

This is why I have found some Autos are rock steady on tikover, then jump and move about shortly after selecting drive,

this could even be the efect I am thinking right now of powering the Torque convertor ?

As I said not all do it, but some defo do, and setting TPS Value in PWM a tad high solves it pretty much

if the TPS Value of the TPS Itself doesn't give as lower reading too this can have an effect. Some GET TPS = 10 some 22

hence my point of looking to see what your TPS GET VALUE is and then add a bit for the PWM TPS Settings

Hope this makes more sense ?

Nige

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy