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Guest larson

Map Readings When Cranking

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Guest larson

Hi,

 

need your advice here.

 

While waiting for replacement high current ignition drivers to be delivered (from VEMS..) :blush: I am playing with settings and checking basic inputs to Megasquirt.

 

Tried to crank the engine and was suprised to see MAP to drop from 98kPa only to 86KPa. Tach reads ~200RPM while cranking.

 

So the question is if it is not way too high? Shouldn't it be more like 40-50KPa or even lower while starting?

 

Could anyone check his data log for cranking MAP readings please?

Need just this part, cranking, not idling.

I'm just too paranoic at the moment, everything seems to be burning, getting hot, not blinking evently etc. :blush: You probably know what I mean.

 

Many thanks in advance.

 

P.S. Bought my MS of eBay (USandA :)). I would suggest not to buy anything if you will not be able to reach the seller by your hand's fist to argue the quality of the product. :P

Literally re-built MS trying to trace the problem, know a little more about electronic components now, that's not bad though :)

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B1ack_Mi16

Think it's quite normal, wouldn't expect it to drop very much just by cranking it over.

Engine can't consume enough air to make proper vacum until quite a few houndred revs, this of course will vary from engine to engine,so I think your values are just fine.

 

Get it started and idle at 900-1000rpm and you'll see it'll make more vacum.

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cybernck

yep, mine is also 70-85 KPa during cranking :P.

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Guest larson

Perfect.

Thanks guys for your answers.

 

Moving forward a least then. :P

 

cybernck, how your megasquirting going?

Quite some time since last posts from anyone installing MS, it makes me worry a little.

 

 

yep, mine is also 70-85 KPa during cranking :blush:.

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snillet

Min cranks in the 80:s area approx.

 

Nice thing with MS is that´s it´s just getting constatly better and better all the time :P

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jackherer
Quite some time since last posts from anyone installing MS, it makes me worry a little.

 

I'll be instaling one soon hopefully, if time allows, so I'm watching this with interest.

 

Can you post details of your ignition setup please, thats the next thing I need to work out...

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cybernck

i'm running it on the negative coil trigger (fuel only!) at the moment, looking to go to 60-2 soon,

first using the standard dizzy and then moving on to wasted spark dual coilpack. makes it easier

(well, not easier but better) doing one step at a time, than having to eliminate one thing after

another in order to trace a fault :blush:.

 

i'm going to use Haltech Mi16 base map posted by petert recently to get it going and then see if

i can improve it on rolling road sessions :blush:.

 

as for the fuel map, i still have to figure out low-revs hi-loads parts of the table (i seem to be getting

15-17 AFR no matter what values i set, rich or lean :P) and do a bit of tinkering with cold starts

as it needs quite a bit of cranking to start up (helps if i keep the throttle open) when engine is cold.

 

p.s. i'm armed with VEMS WBO2+EGT gauge - a great bit of kit!

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Guest larson
Can you post details of your ignition setup please, thats the next thing I need to work out...

 

Going wasted spark route.

Will use two IGBTs (probably the ones from VEMS web shop) to run coil pack (Bosch 0 221 503 407) dirrectly.

 

Using stock VR sensor as RPM input.

 

Just waiting to receive IGBT ignition drivers from VEMS. 420V 14A instead of 340V 7.5A

It was reported several times on the MS'nExtra board that original IGBTs are not good enough if primary resistance of the coil is low.

Resistance of my coil pack is 0.5ohm, it was suggested to use coil with resistance 2 or 3 times higher.

 

However now I'm pretty sure that one of original VB921 was fried because of fault installation, two wires were mixed when the seller installed second ign. driver.

 

That's it for the moment, spent almost a year collecting parts and planning, drawing wiring diagrams and reading :)

New wiring is routed, old stuff (AFM, Ditributor cap, coil and ign. module) is in the garbage bin just to be sure I will not change my mind and turn back to original. Joking, it just died one day and that was green flag for MS project.

WB O2 is still waiting to be installed too.

 

i'm going to use Haltech Mi16 base map posted by petert recently

 

I was not allowed to download this file.. My status is "passenger" yet, that's the problem maybe :)

Anyway I've installed 24lb(~252cc/min) @ 43.5psi (3bar) injectors instead of original ones, just because these were available, cleaned and tested.

Beauty of programmable EMS, isn't it? :)

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cybernck

can you tell me exactly how are you going to wire the original crank sensor to the MS?

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snillet
can you tell me exactly how are you going to wire the original crank sensor to the MS?

 

I know the questrion wasn´t directed to me, but since i run the 60-2 stock VR sensor...

I copied the VR input circuit from the V3 board and put that on a small protoboard inside the casing. Then just connected the circuits together like on the V3 board and the sensor signal into the VR signal input according to the information on the msns-e site.

 

Works very neatly i must say.

 

Actually, i had to do like this since i have a V2.2 board, but when you buy a new board today you´ll have the V3 board, which already has the space for the ciruit "onboard.

Edited by snillet

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cybernck

errm... my MS1 is V3 and i've installed both Hall/Optical and VR circuits

and currently modified it for negative coil trigger but it's easy to go back

to VR (just a few jumpers / wires).

 

my only concern is that there are three pins on the pug crank sensor (iirc)

while MS only has positive and negative inputs for the triggering sensor :).

 

it can't be hard, but i haven't looked into it yet and just want a quick reply :).

 

thanks.

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madspikes

I finished putting my MS in last weekend, and she started up fine and idles great albut a little high. I'm running 405 coil packs, an Mi flywheel and a pug crank sensor. I cant exactly remember how I wired the crank sensor, but I'm sure I grabbed the pin outs from somewhere on the forum. Should be +ve, -ve and shield.

 

My pug cranks at around 200rpm as well.

 

Mad.

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Guest larson

I'll be able to answer your question only after start up and tuning a little. Need higher revs to answer your question for sure.

In case I have "can not rev higher" situation, this could indicate that signal and ground wires should be swiched over on the sensor 1<->2 pins.

 

Used this picture as a reference:

photo.13997154.jpeg

 

However it works with pin 1-sig, 2-ground for me also, at least when starting MS is reading RPM.

Also it depends on how your VR circuit jumpers are set on MS V3 board.

Both VROUTINV-TSEL and VROUT-TSEL will work as indicated in MSnS Extra manual but wires on the sensor should be changed over for every case to work properly.

VROUT-TSEL is the correct way though.

 

Used two core shielded microphone cable.

For the moment I've connected TACH Signal (MS pin 24) wire to pin 2 of the sensor, and ground (any MS ground pin, one of 15-19 in my case) to pin 1 of the sensor.

Pin 3 is shield. Since I was not sure if this is not grounded on the sensor's side I have left this unconnected.

Also I have connected shield and ground wires to the same Ground (any ground pin) on MS side.

Shield should be grounded only on one side, MS preferably.

 

 

I better stop talking now, need to start the engine first. Theory is nothing without practice :)

Just received IGBTs from VEMS (excellent service), let's have some fun soldering.

Will try to spin the engine tomorrow hopefully. Fingers crossed.

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Richie-Van-GTi
I finished putting my MS in last weekend, and she started up fine and idles great albut a little high. I'm running 405 coil packs, an Mi flywheel and a pug crank sensor. I cant exactly remember how I wired the crank sensor, but I'm sure I grabbed the pin outs from somewhere on the forum. Should be +ve, -ve and shield.

 

My pug cranks at around 200rpm as well.

 

Mad.

 

 

which ms are you using? Id be interested in steling your map if its the correct version for my engine Im using ms1 with pcb3.0 and two vb291 coil drivers for wasted spark and the 60-2 flywheel pick up. Also what intake are using? is it running map sensor, temp sensors, lambda etc?

Edited by Richie-Van-GTi

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madspikes
which ms are you using? Id be interested in steling your map if its the correct version for my engine Im using ms1 with pcb3.0 and two vb291 coil drivers for wasted spark and the 60-2 flywheel pick up. Also what intake are using? is it running map sensor, temp sensors, lambda etc?

 

The map isnt vrey tunned at the moment, but the car starts, revs and idles.

 

I'm running MS I, v3.0 board, two vb921s, 60-2 flywheel, 405 wasted spark coil packs, standard inlet manifold and throttle, standard injectors and standard pug temp sensors (two coolent sensors, one for air, one for coolent), innovate wideband lambda.. Oh on a 8v.

 

Should have a better map after the weekend, but your welcome to have what I've got, for use as a base map only!

 

Mad.

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Richie-Van-GTi

yeah sounds ideal, some similar stuff to mine so would be a great starting point. I will be using wasted spark coil, standard temp sensors and same MS setup. Will just have to rescale for fuel and change the TPS parameters as mine is from an R1.

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Guest larson
The map isnt vrey tunned at the moment, but the car starts, revs and idles.

 

Is your VE table generated by MegaTune based on displacement, power and torque figures?

Or you use one of default maps for 4cyl engine?

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snillet

The "screen" on my VR sensor cable is only connetced at ECU side to the casing. The VR sensor mounted to my engine doesn´t even have a PIN where the screen would have been connected. Just +/- connections from the sensor coil. I´ve actually reused the stock loom VR cable which is a double foil screened thing that seems to be fairly good. Tried to put a separate cable using a very expensive microphone cable but it didn´t do anything better then the stock one so i contiuned to use that one.

 

Although i DID have an isue of the resistors in the first stage of the VR circuit being a bit to large to get a decent signal into the first transistor, so i switched them from the "new" MS schematic value to the old one, belive the new was 10kohm and i´m now using 1kohm resistors there instead. Made things work like they should for me.

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SPGTi
The map isnt vrey tunned at the moment, but the car starts, revs and idles.

 

I'm running MS I, v3.0 board, two vb921s, 60-2 flywheel, 405 wasted spark coil packs, standard inlet manifold and throttle, standard injectors and standard pug temp sensors (two coolent sensors, one for air, one for coolent), innovate wideband lambda.. Oh on a 8v.

 

Should have a better map after the weekend, but your welcome to have what I've got, for use as a base map only!

 

Mad.

 

 

This is more or less exactly the same as I will be running apart from a 36-1 crank mounted wheel with a a ford VR and a Nissan TPS.

A base map would be great, if you don't mind.

 

chers

 

Steve

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