wiring injectors, efi relay, fuel pump vsv

[Shifty]

hey guys

i'm wiring up my ecu, some questions - pls excuse me if they're simple but i've never been involved in this side of stuff. it's an adaptronic e420c, the engine is an st215 3sgte and the chassis is an ae82 twin cam corolla.

a) the ecu has only one power wire, which is ignition switched. this seemed odd to me but appears to be the case. let me know if this seems wrong.
b) there are a number of earth wires from the ecu. does it matter how long the earth leads are, or is there any convention as to where to/not to earth them?
c) each injector has a coloured wire that goes to the ecu. that's easy. the other wire is black with a red stripe, i assume this is power supply and that the ecu simply grounds via the coloured wire. so... where dose this black/red wire go?
d) there is a VSV that I believe is somethign to do with the fuel pump or fuel pressure. it also has the same black/red coloured wire... and another wire which I can't remember the colour of just at the moment.

[wilbo666]

hey guys

i'm wiring up my ecu, some questions - pls excuse me if they're simple but i've never been involved in this side of stuff. it's an adaptronic e420c, the engine is an st215 3sgte and the chassis is an ae82 twin cam corolla.

a) the ecu has only one power wire, which is ignition switched. this seemed odd to me but appears to be the case. let me know if this seems wrong.
b) there are a number of earth wires from the ecu. does it matter how long the earth leads are, or is there any convention as to where to/not to earth them?
c) each injector has a coloured wire that goes to the ecu. that's easy. the other wire is black with a red stripe, i assume this is power supply and that the ecu simply grounds via the coloured wire. so... where dose this black/red wire go?
d) there is a VSV that I believe is somethign to do with the fuel pump or fuel pressure. it also has the same black/red coloured wire... and another wire which I can't remember the colour of just at the moment.

a) Correct

b) Shorter the better, connect to a good ground.

c) Battery -> fuse -> relay (ignition switched) -> injectors -> earthed by ECU when required

d) Not sure. I have seen some engine use a VSV off the FPR to raise fuel pressure when hot starting (reduce vapour lock), however I didn't think your engine was that new... take a pic

Cheers
Wilbo

[Shifty]

cheers. re: the relay, is that the main efi relay or will the car have a separate fuel pump relay / should i add a second fuel pump relay?

not easy to see but it's the blue connector in this picture, on the 'back' of the engine at the centre of the engine bay. just behind the coolant outlet. two wires, blue connector, one is black and red stripe, other i think is blue of some description, cant' remember.

http://photos-c.ak.fbcdn.net/hphotos...34_15457_n.jpg

[Shifty]

oh and yes i'd read about the same thing. seems gay & unnecessary to me so I am inclined to leave it out and worry about it only if i have hot start issues!

[YLD-16L]

I just installed my e420c and did a lot of research/reading before I did it and I also did the motec ecu installation and tuning course to boost my knowledge as much as possible.

Only thing I'd add to what Wilbo said is with the ECU earth wiring is ground it to the block rather than the chassis if possible.

[Shifty]

I'm sure that the manual said not to earth to the block but to earth to the chassis....?

[YLD-16L]

I'm sure that the manual said not to earth to the block but to earth to the chassis....?

Manual says:

There are five ground wires; three on the 8-way plug and two on the 6-way plug.
· Depending on your application, they may all need to be connected to a solid
earth near the ECU.



9 times out of 10 a GOOD earthing point on the chassis is fine.

[YLD-16L]

One of the dealers for Adaptronic wrote this up to help people installing the Adaptronic ecu's:

Many people do the Adaptronic ECU installation them self and that's OK.
Most problems we have to give support to are based on grounding problems of the ECU and the igniters.
These problems vary from hick ups or staling on idle to blowing up igniters and in some cases even damage to the ECU so grounding these parts correctly is very important.

If we talk about grounding the ECU and igniters we want a clean ground so inductive load will not influence other systems and resistance will be as low as possible.

We recommend that all 5 ground wires from the ECU will be connected to the engine and not to the fire wall or other grounding point as it will be used by other electrical consumers as well.
Also connecting direct to the engine eliminates a lot of resistance and all the current drawn over the ECU ground will travel direct to the ECU assuming most of the ancillaries are on the engine as well.
It also eliminates a lot of EMC from other electrical consumers as the igniters as well.

Igniters:
Modern igniters can be very powerful boosting up voltage over 80.000 Volt easily.
A normal spark is about 20.000 Volt to >40.000 Volt on boosted engines.
It seems not many people seem to realize that this voltage also travels over ground to the sparkplug as well.
It's not hard to understand if you have resistance in the ground between the igniter and sparkplug there is a change that the spark will be weak? Well yes but also the igniter voltage goes up as it will be harder to get the spark going due to more resistance and in some cases the insulation of the ignition coil can not handle this Hi Voltage and because of this blowing up the coil.

Why do we need a clean ground from the igniter to the engine?
I have seen many cases that people connect the igniter ground to the fire wall or some common ground and what will happen if you do this? Well >20.000 volt will travel over ground to the spark plugs and it will find it's way to get there so it can be that a part of the hi voltage will travel over parts that a not very well build to handle Hi voltage coursing problems or even damage.
Most OEM build cars have a ground wire to the engine close the igniter if the igniter is not mounted on the engine. This ground wire can vary from 2.5mm2 to even 9mm2 in size.
So grounding the igniter directly to the engine gets rid of a lot of voltage spikes and EMC as well reducing a lot of problems with the ECU system.
Believe me I have seen more than 100 volt voltage differential on the 12 volt positive and negative feeds indicating hi resistance.

Also it's better to split the positive feed to the ECU and igniters as well as the igniter positive feed comes from the ignition and the main ECU positive feed comes from the main relay in most cases.

Also one thing to notice if you are installing an aftermarket ECU on the OEM wire loom and cutting of the OEM ECU plug that you still get all the grounding points to the ECU.
I have seem some installations running low impedance injectors on one 1,5mm2 cable pulling 6 amps hold and 25Amp peak current wondering why the engine runs with hick-ups.

Sorting all these things out will clear a lot of things and adding things like suppressors to dampen voltage spikes will not solve most of the problems as it will only mask the problem until conditions chance like cold and worm weather making a big difference on the hi voltage side of the ignition system.

The bloke is from the Netherlands so thats why the english is a bit odd in a couple of parts.

[Chrisso]

I just installed my e420c and did a lot of research/reading before I did it and I also did the motec ecu installation and tuning course to boost my knowledge as much as possible.

Only thing I'd add to what Wilbo said is with the ECU earth wiring is ground it to the block rather than the chassis if possible.

Hi Leigh. I've earthed my megasquirt to the intake manifold, which is where the factory earth point is located. It was previously earthed on the chassis and wasn't up to snuff. As long at the earth is good I don't think it matters, but if you do get odd feedback in your datalog check your earths first and your comms from the ecu to handcontroller/laptop next. Both caused issues for me.

BTW - I'll call you about the exhaust. I've got a free weekend if you're around.

It's for a ST205, not 215, but here's a link to the EWD.
http://www.celicatech.com/imagearchi...5ewd/95ewd.htm

Chris

[timbosaurus]

a) Correct

b) Shorter the better, connect to a good ground.

c) Battery -> fuse -> relay (ignition switched) -> injectors -> earthed by ECU when required

d) Not sure. I have seen some engine use a VSV off the FPR to raise fuel pressure when hot starting (reduce vapour lock), however I didn't think your engine was that new... take a pic

Cheers
Wilbo

a) agreed

b) agreed. In addition, there are two types of earth... signal and power earth. Power earth is for the ECU, the coils, etc, while signal earth is for things like TPS, coolant temp etc. My experience, and what I do, is to run a seperate wire for each earth (regardless of type) all to meet at ONE SINGLE EARTH POINT. If that is too many wires, you can join all of the power earths into a heavier guage wire... but make sure that the signal and power earths don't meet until the common earthing point, as this creates ground loops. It doesn't reeeaaally matter whether this is the block or the body, as long as you link the two with a good earth strap.

c) agreed. In addition, it is worth noting that each injector might average 1-5amps depending on type, since they don't run all the time you'd want to plan for ~10amps for four. This current will flow through the injectors, to the ECU, and through you're aforementioned ground wires... so make sure you consider that when you are think about how much current the power earth sinks.

d) VSV is a vacuum solenoid valve, and can be used to describe lots of functions. I'd suggest on your car it is either the charcoal canister vent valve, EGR valve or if you're car is OBD2 compliant it could be the evap solenoid on the tank. Sorry I can't help more without schematics.

[YLD-16L]

b) agreed. In addition, there are two types of earth... signal and power earth. Power earth is for the ECU, the coils, etc, while signal earth is for things like TPS, coolant temp etc. My experience, and what I do, is to run a seperate wire for each earth (regardless of type) all to meet at ONE SINGLE EARTH POINT. If that is too many wires, you can join all of the power earths into a heavier guage wire... but make sure that the signal and power earths don't meet until the common earthing point, as this creates ground loops. It doesn't reeeaaally matter whether this is the block or the body, as long as you link the two with a good earth strap.

Not to confuse this too much but with the e420c (and most modern ECU's) convention is that ALL the sensors feeding into the ECU are to be grounded internally via the ECU to minimise noise.

The e420c loom is already setup to acheive this with the addition of one extra ground wire for one of the sensors.

[Shifty]

ok so:

all the sensors ground via the ECU
all the ground wires from the ECU ground to the block

[Shifty]

ps: fuck I hate wiring. fucking nerdy fags with their resistance and ohms. i just want to do skids.... does anyone want pizza/beer/cash to swing by my place and wire it up for me? i can look over your shoulder and/or get in your way if you like

haha

[YLD-16L]

ok so:

all the sensors ground via the ECU
all the ground wires from the ECU ground to the block at a single point if possible as Timbo pointed out

Correct.......

[timbosaurus]

Not to confuse this too much but with the e420c (and most modern ECU's) convention is that ALL the sensors feeding into the ECU are to be grounded internally via the ECU to minimise noise.

The e420c loom is already setup to acheive this with the addition of one extra ground wire for one of the sensors.

Oh, that is handy

So there is one wire out of the ECU for combined sensor ground, and another one (or more) for power grounds? Nice.

I've never worked with adaptronic or autronic. FYI, I've actually just bought a Wolf V500 to play with, and it's bloody great!