Miked5

I have decided to go with the extra relay as per the photo in my previous reply, everything seems to be getting voltage as it should so happy with that. Now to wire my gauges & column switches up! 

Reg - R53 FGC

mk1 1997 1.8

Thanks Simon, so I think my main problem is that the MX5 ME221 ECU works differently to the Emerald that GBS use (guess who's wishing he bought an emerald now!), it does not have power supply pins which can be earthed etc. I'm guessing because it's a plug&play ECU. 

Looking at the mx5 diagram it has 3 power supply wires:

Main Relay - Wht/Red - goes to ECU & every engine sensor apart from the 2 below

Engine Fuse - Blk/Wht - 12v supply to coil pack (ECU activates the coils with 2 separate wires) 

Meter Fuse - Blk/Yel - 02 sensor heater supply & check engine light 

Let me know what you think but the only way I can think about making it work is grounding pin 3 to chassis or battery to activate Pin 2. I was then thinking of adding another relay into the mix because I wasn't sure running everything from pin 2 was the right thing to do. Something like sketch in the link. 

https://imgur.com/a/cq5wZUf

Thanks that explanation has helped me to understand it better. I've connected pin 1 to my ECU and confirmed all sensors are receiving correct voltage, the sensors left are O2 sensor and coil pack which on the Mazda are powered from a different wire compared to other sensors. 

I'm still struggling with pin 3, do I connect this to my coil pack and O2 sensor 12v supply? Basically these are my last 2 sensors I need to supply 12v to. But when I connect my coilpack wire I am reading 6.8v at both coilpack pins which is confusing me.

Hi Guys I'm hoping someone can help me make some progress with my gbs wiring, I'm a bit stuck on the engine plug which spurs off from the chassis harness to my MX5 ME221 ECU.

It's mainly the top 3 pins I need to figure out where they go, the others should be ok. 

1. Which pin do I use for main 12v ignition to the ECU? (On the OEM diagram it comes from the main relay to most of the sensors except coils and to ECU Pin 4B), I'm a little confused because Pin 2 sounds like the one but I'm measuring no voltage here. I've put a link to the schematic of the relay.

2. Pin 3 main relay control (coil, injection, lambda) I'm planning on connecting the ignition coils here but the notes state "emerald switches to earth" but I'm using an ME221 will this also switch to earth? I don't want to blow anything inside the ECU.

If there are any mazda builders that can confirm which pins they used for what that would be a great help. 

https://imgur.com/eRrk20Z

https://imgur.com/se8BFkq

Not sure why it won't let me add a photo from imgur I'm sure I used this method last time. 

Removed from my GBS to fit smaller motorcycle ones, I believe these are used to pass IVA for the spacing, height criteria. CV boot to hide extender bracket. Fully working order. 

£25 inc delivery. 

A battery can read 12v but have no cold cranking amps which is the power/load it needs to turn the starter. I've seen this before. Sounds like new battery time

Cheers Alan, I will keep my eye out for the next meet itll be good to meet up with local owners. 

Hi guys I currently have the mx5 mk1 alloys fitted to my Zero (fitted when I bought it) so looking for something to replace them. The inside of the alloys are currently about 5mm away from the wishbones

I'm struggling to find any 2nd hand alloys in the ET15 required for the zeros, now I've found some TD pro race 1.2's on eBay but they are ET25. The question is how close will these be from the wishbones? Could I run a 10mm spacer to bring the alloys close to a ET15 fitment? Is anyone else running ET25 with no issues? 

Mike 

Spliced into the HP Pump wire and starts perfect every time now.
 

First issue sorted now to move onto the fuel gauge not working, mine has a mx5 cluster and aftermarket sender from JG supplies according to the receipts. I think the ohms range for the sender is different to the mx5. Just reading empty all the time. 

As per title looking for a set of alloys for my Mazda GBS Zero, ideally team dynamics pro race 1.2 15" ET15 4x100 in Mazda fitment.

5 hours ago, nelmo said:

If you have a LP pump, you must have a swirl pot, no? Or is that built into the tank on a Mazda? (I have a Ford). I can't hear my LP pump either, except when low on fuel and it starts struggling. The Emerald ECU only runs the pumps for a few seconds if you just put the ignition on and then switches them off if it does not detect any attempt to start the engine. Maybe your ECU does the same, so by the time you go to measure the voltage, the pump is already off, hence 0v?

If the engine is starting and running, the LP pump must be working otherwise how is petrol getting to the swirl pot? Can't imagine the HP pump has enough oomph to suck fuel from the tank, through the LP pump? 

To check, disconnect the pipe after the LP pump (inlet to swirl pot if it is separate) and switch on the ignition - see if any petrol comes out. 

If I'm talking crap then, yeah, splicing from the HP pump should be fine, I'd say

Thanks for the reply

Yes I have a low pressure pump > swirl pot > high pressure pump, I have the multimeter already attached to the wires ready for when I turn the ign on so definitely getting 0v all the time. 

The engine doesn't start first time this is why I suspected the LP pump, now I'm getting no power to it it kind of confirms it. Funny you say that because that is exactly what I have done ha I disconnected the swirl pot fuel inlet and put into a bucket  , ignition on and nothing at all came out. 

1 hour ago, marlin said:

Miked5, I’m running  a Haltech Ecu and had to run the LP pump via a wire to HP pump even though using GBS loom. Just use the wire in the loom and run it to the hp pump. Works fine. 

Thanks Marlin I will give this a try, guessing you spliced into the HP pump wire after the relay?

Should the low pressure pump run continuously when ign on and engine is running? Could I splice into the wires that go to the high pressure pump? So both will run together 

42 minutes ago, blue said:

Are you running the factory wiring loom ?

the low pressure pump is run by the emerald ecu on the factory loom BUT the wire for it comes from the ENGINE loom plug and just needs to be put to earth it will then come on with the key 

I have the wiring dia somewhere and will let you know the colour 

Yes factory Mazda loom so there is a spiders nest behind the dash Is emerald an aftermarket ecu? I still have the Mazda one. It is a blue with red stripe wire currently going the the pump and ground which goes to the chassis but when reading with a multimeter I get 0 volts  

43 minutes ago, theduck said:

Hi, I assume you didnt build the car originally? Do you know if the builder used a GBS supplied loom? Its possible to buy other off the shelf looms, or of course they could have scratch built it.

No it was already built when I purchased it, he said he paid someone to do the wiring side of things. 

Had my Mazda zero a few days now and realised it never fires first time round, normally 2nd or 3rd time. I can here the high pressure pump whining when I put ignition on but nothing from low pressure pump. 

Ive had a multimeter on it and I'm ready 0 volts to the pump, the question is does anybody know where the power to the pump is fed from before I have to rip everything apart to trace the wires? For example which fuse or pins etc. Is there a wiring diagram I can get from GBS which will help me? 

Mike

9 hours ago, nelmo said:

Welcome to the club - good looking car - what sort of price, may I ask?

 

£6600 - new to kit cars but most that I saw for sale were 8k+ for finished articles. 

3 hours ago, Andrew Howe said:

Hi Mike i will be nearest to you i would think, i am in penrith area. Not a good time to be meeting up at the moment  with all this going on, but keep in touch we will meet up and have a run out . All the best happy tinkering.  Andrew.

2 hours ago, Allan Royds said:

Hi Mark.

Welcome to the club I might have one up on the location your car looks very nice and look forward to get the chance to see it soon.

Regards Allan

Looking forward to attending some local meets once covid calms down 

Hi guys,

Bought my first kit car last week and just got delivered today I am over the moon with it, can't wait to get tinkering over the winter. It's a Mazda GBS Zero which was IVA'd in 2019 and has only done 400 miles since, and bought at a bargain price may I add! 

Found a few small issues today that I can crack on with right away but the previous owner has done a great job the car is in great condition. 

The plan is to get used to driving it first (its my first kit car) then hopefully fit a td04 turbo which will get it to the bhp/ton of my previous car r35 GTR. 

If there are any owners in the north east near Barney then feel free to get in touch. 

Mike