MS3X Starting Problems - MPi Trigger Wheel Sync (Now Working)
Turbo Mini Forums

Evening,

So i've been busy building up the mini with fuel injection. (Hence no post updates as been far to busy building) I'm currently running the mini mpi engine and hardware with an MS3X, before putting on my turbo manifolds etc so that i can run the engine in and check for bugs

I can't get it to start. Looks to me like I have no cam signal. Below is a plot of the composite log.
It's the mpi cam input so I'm pretty sure it's a VR sensor. Therefore i have not jumpered the pins on the extra board.

I'm not sure if the the relevant chaps still use the forum but we'll see. I'll also post on msextra forums

Edited by dan187 on 25th Jun, 2013.

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

You're right there is no cam signal reaching the MS3.

How many wires does the sensor have and how is it connected to the MS3? Also, have you tried adjusting the pots on the MS3X?

http://www.jbperf.com/

Thank you for the response. Good point... it has 2 wires so yeah a VR sensor. It has one wire plugged into the MS3x extra card and the other (and shielding) plugged into V3.0 board. I'll check tonight that i've connected it to the correct pin (32). However, i think the problem may be the polarity. When wiring it up i think i just guessed based on the colour of the wires (i think black and blue, & red and yellow) So i made the one with black in go to ground. Am i right in saying that it needs to be the correct polarity?

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

Possibly a silly question but, as you say you're about to put manifolds/turbo on, has it got the MPI camshaft installed still ?

I ask as it wouldn't be a normal choice for a turbo build.

The MPI cam is the only one that will work the MPI VR pickup.

Can't help with MS3/MS3X wiring as I use MS2 but yes, the VR circuits are sensitive to polarity.

Do you have access to a scope (easiest way to check signals).

Schrödinger's cat - so which one am I ???

Could have the MPI cam reground to another profile I guess?

If something is worth doing, it's worth doing half of.

Or modify any turbo friendly cam to accept the MPI sensor.

Basically what Leyland/Rover decided to do was use the fuel pump lobe on the cam to be the VR cam input (as no mechanical fuel pump was req'd) but VR sensors don't like curves, they prefer squares (like all your MJ 36/1 wheels), so they machined a big groove through the fuel pump lobe and the VR sensor sits in this groove and picks up off the edges of the lobe rather than the top of it.

So it's easy enough for a decent machine shop to replicate the groove on any cam that has the fuel pump lobe.

Schrödinger's cat - so which one am I ???

Interesting

If something is worth doing, it's worth doing half of.

I've found my Rover pirate CD and the MEMS wiring diagram doesn't show which wire colour is +ve/-ve.

Very annoying because it does for the crank sensor and the O2 sensor. Maybe the MEMS input circuitry wasn't sensitive sensitive to polarity on the cam sensor ?

Anything with black is usually a good start to assume negative but not with Rover - the IAT sensor +ve is green/black :)

Schrödinger's cat - so which one am I ???

I'll check wiring this evening and also see if i can borrow a scope from work to test polarity (failing that i'll just swap it over).

wrt cam... it is by no means the best camshaft for a turbo application but should be adequate for a low boost daily. Perhaps when funds allow I'll get something more appropriate machined. I'll let you know how well it works once the turbo additions are up and running. (will be a few months yet). Want to cement my efi knowledge first

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

but the main colour is green, so it says it's power is controlled by the ignition switch, which comes close. the secondary colour only helps to identify the wire

i guess it depends if rover used rising or falling edge. That'll dictate what they call the earth wire.
i'll check tunerstudio to see if i can invert the cam independent of the crank (which looks to be working)

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

Yes i moved to the darkside

Instagram @jdm_brett

http://www.jbperf.com/

ok, thanks for points guys.
I checked for sensor resistance 1250 ohm - good
checked for sensor voltage 20mV - good

so played with pots some more - now better - i have cam signal. (obviously too tired to get them correct last night)

However, still no start....

first image shows my composite log without sparks plugs in (no errors)

second shows me trying to start the engine (lots of errors)






edit: added images

Edited by dan187 on 21st Jun, 2013.

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

what should the rover #2 plot look like? where does the cam trigger sit in relation to the flywheel?

so i gather... With the engine at TDC on number 1 cylinder, the first missing tooth is at 30 degrees.

Missing teeth at 30, 60, 210 and 250

There are 2 teeth between 30 and 60, 14 teeth between 60 and 210, 3 teeth between 210 and 250, 13 teeth between 250 and 30. 0 being TDC on #1/4 cylinder, 180 being TDC on #2/3 cylinder

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

bit more tuning makes it look better



however, still get drop outs when spark plugs are in (whether electrically connected or not)

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

Must read first.

Edited by Paul S on 21st Jun, 2013.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

it's an mpi wheel 36-1-1-1-1 (in an mpi engine)

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

How have you set up the fueling? Are the spark plugs wet?

Edited by Paul S on 21st Jun, 2013.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

i think so
msq can be found here if you have time to look for me?

https://dl.dropboxusercontent.com/u/1566128...tTune%20(1).msq

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

oh and yeah plugs are a little wet

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

It's been a couple of years since I did this. No time to read the .msq.

How have you wired the injectors? How have you calculated REQ_FUEL?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Also, how have you set the tooth angle? Are you getting a spark now that the cam signal is working? Is it in the right place/phase?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

i've used the test functions to show spark and injection are good. Req_fuel is based on the msq you sent me x1.275 for my larger engine.

tooth angle may be the culprit. i'm not sure what it is because of the crazy rover wheel. i'll see if i can find out.

itstrugles to sync so sometime does't turn on the fuel/ spark relay

1275 N/A Sprite, 998 T2 Turbo Mayfair
1275 EFi Turbo

Have you wired the injectors to channels A & C ? You may have to change them to B & D as you can't adjust the cam sensor angle.

EDIT: Of course adding 180 degrees to the injection timing will have the same result.

Edited by Paul S on 21st Jun, 2013.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."