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

[Hybrid_From_Hell]

If you have read up to this far then you will have a base idea of what MS is all about, some long ways back when I was talking about "Spark" I posted up my MAP for SPARK and said "DO NOT USE THIS" as it is for a quite highly tuned engine.

OK then, what comes now is a sort of "Told you so"

and that spark is something that can both vary from one engine to another even when they seem the same - ie what appears to be identical engines - ie one 3.9 factory lump vs another 3.9 factory lump.

Add an engine in such as mine ..........and the spark map can be very different again....

I should have listened to myself

I have FINALLY got my mates racer engine to run properly,

when I say properly I mean to go like a scalded cat,

and not as it - was which was firing on all 8 cylinders, - but as dead as a dead thing,

he described it as "Racing towing a loaded trailer"

I won't bore you with what we did,

HUGE amounts of though effort tweaks mods checks and changes were made, none really did it,

all were "Well, yea a bit but still dead".

The engine for those of you curious is a home built V8 3.5 ex carbed the efi'd then MS'd V3 029v MS SnE

with the heads and block both skimmed 'a ludicrous amount'- 60 and 40 thou ,

the cam (whizzy one) also advanced a huge number of degrees, both heads inlet manifold etc ported by hand - prob as big - or bigger than mine,

extractor exhaust and so on, .....and other 'internal mods', its a "Screamer " or should that be "Was a screamer - now a smooth ..but low powered V8"

Then one day an idea hatched, we were desperate and were running out of ideas, and as a non road legal motor logging was tricky too had to be race meetings...

we peered at the old dizzy.

Looked std enough, then we saw the lathe marks on the INSIDE of it, (allows more advance) and the altered bob weights ....and the springs that were different,

- refitting it and closing down MS Spark, so it had dizzy and MS fuel only made it back to its firebreathing old engine.

Some readings in his work yard were then taken in a way to have scared a health and safety manager to death,

........and much burning of grey cells My T20 his and my scrappy notes .............this was produced. "Kin Hell" sums it up nicely

I would say that we will be adding in MORE advance yet, in the meantime its not ONLY waterproof, but back to its firebrething past -

now THATS some advance

Goes to show how V8s can be so very different in the spark dept,

The 2nd bit of the update is around data logging,

Again this was initailly a problem on the above engine where I had a T20 laptop connected to the ecu wedged behind a seat and the racer was screaming around the site logging itself, it was a hugely cold wet day, and the logs we got all seemd to point to an O2 Sensor failure or even bad earth,

again loads of checking and proding did find nothing at all wrong,

even fitted a new sensor, but the logs all showed it as weak, and the O2 as a possible faulty part / readings

I have also been helping a forumeer with some tunning,

I have got his MAP and spark now to a point where its prob close to right,

yet he sent me one log which reminded me of mates racer log,

as it tried to richen up the fuelling massively, again I thought 02 failure / wiring prob, .....then looked at the datalogs in excel

These showed readings for the O2 that were 4 and 5 !!. (should be 0-1)

A call revealled the issue - it was a freezing cold day and wet as hell,

the drive home in torential rain meant the exhaust was being soaked with water (as was mates racer on the race day loggin)

and the water was cooling down the exhaust and even the heated Lamda sensor, .............

thus false readings. ...........I asked Forumeer to relog in the dry - prob gone.

SO beware do NOT go a logging your engine in very wet conditions, EVEN with a heated sensor

Thats all for the mo, thought the aboves would be useful knowledge for some

Nige

[RangeyRover]

Goes to show how V8s can be so very different in the spark dept,

So there goes the conventional wisdom that you cant go beyond 38 degrees on full load!

[landybehr]

Hi Nige,

has there been some kind of aviation fuel used with that ign. map ?? Or LPG or E100 at least ??

Or ... trigger offset in MS other than expected ???

[Hybrid_From_Hell]

Hi Nige,

has there been some kind of aviation fuel used with that ign. map ?? Or LPG or E100 at least ??

Or ... trigger offset in MS other than expected ???

Nope std unleaded and it goes like STINK Trigger offset and all other MS settings normal

Nige

[RangeyRover]

Gents,

Could someone post up a an msq file for a 3.9 V8 on MSnS Extra 029v firmware please.

Got the squirt built but some faultfinding for the Ignition input required.

Don't really want to get into all that before I have a map that makes V8 sense in.

Could someone please confirm the input cct for me?

There is a lot of contradictory information out there.

Could you confirm that the mods I need to make to the input and output ccts are as here

MS extra

And not as here

which is from http://www.megamanual.com/ms2/EDIS.htm

V3.0 main board:

* DB37 pin #36 to the SAW pin (#3) on the ignition module

* DB37 pin #24 to the PIP pin (#1) on the ignition module

* On the V3.0 main board:

o use the 'Hall sensor circuit' (step #50.a in the assembly guide) - jumper D1 and D2,

o jumper OPTOIN to TACHSELECT on the bottom side of the PCB, near the DB37 connector, opposite the heat sink,

o jumper TSEL to OPTOUT on the bottom side of the PCB, near the center.

* jumper JS10 to IGN (this uses the processor port for the SAW signal directly),

* jumper XG1 to XG2 on the bottom side of the PCB, near the 40 pin socket,

Thanks

only getting intermittent triggering from Jimstim, when I take the jumper off and on for primary tach. all the rest running though.

[FridgeFreezer]

This is how I usually do it:

(Note this includes PWM idle as well)

[RangeyRover]

Thanks Fridge

Tried to send a PM but your inbox is full.

That looks like the way on MSNS Extra.

There's so many different ways to wire these things up, Its like wading through treacle trying to find the right info.

Cheers

Mark

[bobtail84]

Ok here goes... HFH and myself have been trying to find out why my engine wont pick the revs up when you 'blip' the throttle or come to a halt and dip the clutch. We've played with the valley and PWM settings but it still does it. BUT if i hold the rev's on my heal as im breaking then its ok. Tonight i've changed the PWM to warmup only and it ticks over very nice, no stutter when i 'blip' the throttle. I've checked for air leaks and i dont appear to have any. Since i've changed the settings when i turn the engine off i dont get a 'ticking' which happens about 50% of the time and stops when i put all lights on. I have put the same diode as HFH put into his alternator light wire on the PWM wire as it seems that there is a pulse. It seems to be on the earth side so could i have made a mistake on the MS wiring but why would it pulse on the earth with the ignition off. The main relay ticks as well but on the earth from MS side. What have i done wrong?

Jeff

[FridgeFreezer]

A ticking on the earth side? Can you elaborate on exactly how you're observing that? The diode wants to be in the alternator warning lamp wire to prevent backfeeding. When the ticking occurs, do you have any lights on the ECU or elsewhere?

[pinzi]

More info about feul injection and turbo's http://www.dune-buggy.com/turbo/turbo_fi_basics.htm interesting site

[bobtail84]

A ticking on the earth side? Can you elaborate on exactly how you're observing that? The diode wants to be in the alternator warning lamp wire to prevent backfeeding. When the ticking occurs, do you have any lights on the ECU or elsewhere?

The ticking is coming from the main and fuel pump relays. Under the bonnet you can hear ticking like an injector but i have disconnected all the injectors and it was the PWM valve. There are no lights on the ECU but the battery warning and oil pressure lights are on about 50% brightness when its ticking. If i unplug the PWM it stops. If i pull the main relay out it stops. If i pull the fuel pump relay out it continues. This is all with the ignition off. I i turn it back on then of again it starts ticking with all of the above. The engine turns off as normal.

Jeff

[TomG]

The ticking is coming from the main and fuel pump relays. Under the bonnet you can hear ticking like an injector but i have disconnected all the injectors and it was the PWM valve. There are no lights on the ECU but the battery warning and oil pressure lights are on about 50% brightness when its ticking. If i unplug the PWM it stops. If i pull the main relay out it stops. If i pull the fuel pump relay out it continues. This is all with the ignition off. I i turn it back on then of again it starts ticking with all of the above. The engine turns off as normal.

Jeff

Is the +12v feed to your PWM valve coming from the main relay or a permanent/always on 12v feed?

Are all the earth connections good and tied into to the same point (for all MS related components)?

[bobtail84]

Is the +12v feed to your PWM valve coming from the main relay or a permanent/always on 12v feed?

Are all the earth connections good and tied into to the same point (for all MS related components)?

The live feed for the PWM valve is the brown and orange that was on the end of the Lucas ecu connector. Its 87a on the main relay and it used to feed the AFM as well. All MS earths are separate and go to No1 battery earth. The engine earths to No2 battery.

The wiring diagram is the same as the Haynes Lucas hot wire.

Jeff.

[FridgeFreezer]

Why have you earthed the MS separate to the engine then? Doesn't sound like a great idea to me

[bobtail84]

Why have you earthed the MS separate to the engine then? Doesn't sound like a great idea to me

Erm, I just run separate earths to that battery and all bar 1 earth strap for the engine were on the other side so i connected the earths to the other battery via the chassis. Mistake, possibly?

[FridgeFreezer]

Are the two batteries connected together or on some sort of split-charge affair?

[bobtail84]

Are the two batteries connected together or on some sort of split-charge affair?

Connected together with an alternator to each battery and no split charge.

[FridgeFreezer]

Just so I can understand your setup - you have two alternators and two batteries, so what's running what here and what's connected to what?

[bobtail84]

Just so I can understand your setup - you have two alternators and two batteries, so what's running what here and what's connected to what?

From the front of the car looking to the bulk head the left hand alternator and battery are the original fitment supplying the normal 12v systems on the car. This is also supplying the new loom that is fitted to the 3.9 that I've dropped in. The car is an 84 RRC originally fitted with a 3.5 on carbs. The right hand alternator and battery supply winch, cooling fans and spots.

[bobtail84]

A ticking on the earth side? Can you elaborate on exactly how you're observing that? The diode wants to be in the alternator warning lamp wire to prevent backfeeding. When the ticking occurs, do you have any lights on the ECU or elsewhere?

If i put the multimeter on 85 which is the MS earth and 30 which is the main 12v on the fuel pump relay with the ignition on I have 12.8v till the MS pulses then 0v till cranking.. When I turn the ignition off it shows between 2v & 6v and a "ticking" as if the relay is trying to complete a circuit. If I remove the relay the "ticking" is coming from the PWM valve, if I disconnect the valve the "ticking" stops and when I reconnect it does not start again. I've tried shorting the alternator warning lamp wire to see if the "ticking" stops but it doesn't. The alternator warning and oil pressure lights glow dimly. I'm going to check the earths again but do you think I'm getting resets??

I prostrate my self at the trotters of the fridge..

Jeff.

[Hybrid_From_Hell]

I'm going to check the earths again but do you think I'm getting resets??

Connect Lappy and go driving, switch on Megatune, switch on logging too as you need to ping me it now air leak identified and sorted ?

look at the bottom RHS of the screen "RESETS" should equal zero for as long as you drive........ ?

Nige

[bobtail84]

Connect Lappy and go driving, switch on Megatune, switch on logging too as you need to ping me it now air leak identified and sorted ?

look at the bottom RHS of the screen "RESETS" should equal zero for as long as you drive........ ?

Nige

I only show resets if i turn ignition off then on again.. and i want to sort this out so I can send you a proper MSQ..

[FridgeFreezer]

I only show resets if i turn ignition off then on again.. and i want to sort this out so I can send you a proper MSQ..

Well turning the ignition off and on again counts as a reset - if you get more than one, or get them when you haven't done anything, then you have a reset problem. It sounds more like a backfeeding issue.

If i put the multimeter on 85 which is the MS earth and 30 which is the main 12v on the fuel pump relay with the ignition on I have 12.8v till the MS pulses then 0v till cranking.. When I turn the ignition off it shows between 2v & 6v and a "ticking" as if the relay is trying to complete a circuit.

OK, so something is backfeeding into your ignition live, the ticking is the relay & PWM valve trying to actuate (probably because the MS will be trying to power up too, it uses very little current to wake up), as they try to move they load the circuit enough to drop the voltage and knock them off again, so they cycle like this. Did you short the alternator warning lamp across itself or to ground?

[bobtail84]

Well turning the ignition off and on again counts as a reset - if you get more than one, or get them when you haven't done anything, then you have a reset problem. It sounds more like a backfeeding issue.

I'm not getting resets at any other time.

Did you short the alternator warning lamp across itself or to ground?

I pulled the wire off of the alternator and earthed it on the alternator body.

[bobtail84]

I'm not getting resets at any other time.

I pulled the wire off of the alternator and earthed it on the alternator body.

I've shorted the warning lamp wire on the battery -post and it still ticked... also had a good listen and the PWM doesn't appear to be the source of the ticking, it 'sounds' like an injector so I removed each connector but it still ticked. If i feel round the back of the plenum where the fuel pressure regulator lives I can 'feel' the ticking vibrating the fuel rail... So, the fact that I took the live for the PWM valve from pin No2 of the luc@rse plug which is the brown & orange that used to feed the AFM and is also the live feed for the injectors is probably a bumstear because if the MS is feeding back through the earth then any pulsing through the PWM would also pulse the injectors. Would that indicate that there is a live short to the chassis but with a small voltage, just enough to wake the MS and i've noticed that the oil pressure gauge rises to 60 psi which is top of the shop but when I turn the ignition off and the ticking starts the gauge stays at 60 but when I pull the wash wipe switch the ticking stops and the gauge returns to 0. If the ignition is off there should be no power to the wash wipe stalk so what am I looking for?

Jeff.