Im just installing megasquirt into my 89' mk2 8v. I need to connect the megasquirt input to the fuel pump relay so that the relay switches when megasuirt is powered up. I am having a drama trying to find out which wire is the input to the fuel pump relay. Ive read the hyanes to death - no joy. Iv taken out the fuse box and have traced the wires, im happy that i have found the switched power for the fuel pump but cannot find the input to the relay. Iv also read many times the fuse box FAQ but im still no better off. Please can someone tell me which wire it is im looking for. Thanks Tom.
try this, Thanks to rub jonny. http://www.clubgti.co.uk/forum/showthread.php?t=145317 It will be in there
Thats what iv read loads, still no better off, i have even taken the fuse box out and stripped it to find out which pins connect to the blades of the fuel pump relay. Im still have not figured it out. please help if you have an idea
yeah, i have that bit worked out, and i have atteched that wire to the megasquirt pin 37 for the fuel pump relay as is shown in the megamanual. Still does not prime. What does this wire attact to for a normal digi car - looks to me like the ecu. it's a 12v feed so would just grounding this flick the relay? Also when the ignition is primed i get 12v across D13, so the relay has a 12v feed going throught thr' the low voltage side - why does the relay still not switch? cheers tom
Ill try and explain alittle better what i have done and what im trying to acheive. Im installing megasquirt into my 1989 Digifant Golf, I have changed the engine for a 16v and so have removed the Digi ECU and attacted ECU wiring loom. I have built my own loom for the megasquirt ECU and am upto the stage switching the power on Iv had mild success, the ECU powers up and connects to the laptop, the O2 sensor has power and heats up correctly. So im happy that my wiring skills are there. I have been using the this wiring diagram, i have copied it to the tee. You can see that the fuel relay has 4 conecting blades on it. They are 86, 87, 85 and 30. The 86 blade is 12v switched ignition. 85 is the ground that goes to Megasquirts pin 37, 87 is the output to the fuel pump and 30 is the live 12v fused feed from the battery. This is how i have wired up my fuel pump relay but it fails to prime, there is no voltage getting to the connector on the fuel pump, i know the fuel pump is in full working order. So it seems to me that the 87 blade is not receiving anypower becuase the relay has not swsitched. blade 86 is definatly getting 12v as i have messured it, blade 30 is also getting the 12v live feed - measured this too and blade 85 also has a 12v feed measured this too, so im getting power to the right places but the relay still fails to switch. I also seperated my fuse box and decieded to find out what the relay blades feed too, so i got out my ameter and measured each terminal in turn. For the 80 fuel pump relay. Blade Terminal 86 Switched 12v ignition also feeds to... A 8 - blk - ignition switch pin 15 13- blk/blu- hazard switch pin 15 25- blk/yel- fusebox pin L/1 C 20- blk - radiator fan run-on control unit pin 2/15 D 2 - blk - thermal switch for inlet manifold heater (carb models) or fusebox pin R/1 (digifant f/inj) or idle & WOT switches - blk/wht- idle overrun cut-off valve (carb models) - blk - knock sensor control unit pin 5 7 - blk/yel- low coolant level switch unit pin 6/15, idle boost control unit pin 2/15 (K-Jet f/inj) 15- wht/vio- resistance wire -> ignition coil pin 15. NOT present. 16- blk/red- reverse light switch (M/T) or starter/inhibitor & reverse light switch pin 15 (A/T) 23- blk - ignition coil pin 15 EDIS Ignition coil G 2 - blk - heated washer jets, spare plug behind fusebox & idle stabilser valve pin 2/15 5 - switched power spare terminal. Megasquirt ECU 12v power supply. Blade Terminal 85 Relay ground also feeds to... D 13- vio/blk- thermal switch for carb heater, inlet manifold heater, auto choke & bypass cut-off valve (carb models) - red/yel- electronic ignition control unit pin 10 (16v) or digifant ECU pin 3 (digifant f/inj) - red/yel- knock sensor control unit pin 10 (16v) Megaquirt Pin 37 Blade Terminal 30 12v live battery feed also feeds to... Permiment 12v feed. B B23 11- gry/red- cig lighter - red - radio power plug pin 7 12- red - digital clock/MFA 13- red/yel- indicator stalk pin 30 (headlight flasher/main beam switch) 23- red - light switch pin 30 28- red/wht- hazard switch pin 30 C 3 - red/yel- brake light switch 7 - red - radiator fan thermal switch & radiator fan after-run relay pin 30 E3 E 3 - red - interior light & boot light K 5 - brn/red- ignition switch pin S or SU (difficult to make out!) P All spare terminals, they are 12v feed with ignition off. - red - battery +, ignition switch pin 30, electric window relay pin 87, headlight washer relay pin B/30 & f/injection relay pin 30 (K-Jet f/inj) Central locking. Blade Terminal 87 Relay 12v Live to fuel pump also feeds to... E 14- red/wht- warm up regulator, aux air regulator & control pressure regulator (K-Jet f/inj) - red/yel- main & transfer fuel pumps N - red/wht- inlet manifold heater - red/blk- f/injection relay pin 86 (K-Jet f/inj) Empty. After writing all that and thinking it over im going to try running terminal 85 stright to ground bypassing the megasquirt pin 37 - ill see how that works.
blimey you didnt need to do that, ive got an 89 diagram which shows all the current paths inside the fusebox Fuel pump socket pins are as follows: 1 - Earth 2 - Live 3 - Output to fuel pump 4 - Ignition live 5 - Pin D/26 & B/19 - Red/black wire from coil (rev counter feed) 6 - Pin D/13 - Digifant ECU pin 3 7 - Pin B/18 - Ignition switch pin 50
Thanks for getting back to me rubjonny, Im understand what you have posted there but I do not know what the numbers 1,2,3 etc refer to, becuase the relay itself only has 4 termials, do you have a diagram? Also would it be possiable to get a copy of that diagram with the fusebox paths? cheers Tom.
The 16v/digi fuel pump is primed via the ecu and hence has a different relay to the 8v kjet (or so i understand it) would potentially account for your lost 12v? now i think about it i cant remember if the digi is different to the 8v kjet can some one confirm?
The 16v relay is different to the digifant relay, you might find a 16v relay works better? As for the pin numbers, they refer to the sockets on the relay board itself, if you want to figure out which is which I believe they are written on the front of the fusebox? Unfortunatly the CE1 pic in my FAQ doesnt show the socket numbers, but the CE2 pic does. If ya want me diagram, pm me your email addy
Every cloud has a silver lining, as i suspected that grounding the relay terminal 85 would switch the realy on. It did and the fuel pump primed continuously and also then when i went to crank the engine the starter turned very happy. Also I had the engine running breifly like this so there is my silver linning. Im very happy, it needs some tunning as it runs breifly then stalls - not a drama as i didn't have any time to play today. But this means that i have a problem with my megasquirt, why does it not earth the 85 pin as it should? Im running Ms 1 extra any help or advice would be greatly appreciated again. Thanks to all those who put input into helping me, it's sometimes just nice to feel like you can sympaphise. And I quite enjoyed taking the fuse box apart and tracing the paths - i learnt so much yesturday it was actually really worth getting stuck.
Success! I emailed the guy a bought the ECU from and he told me to make shaw I had the correct settings switch on, if I did and it still failed to work to send it back to him. I confirmed that I did have it on the correct settings but it still failed to work. I popped it in the post and he received it yesturday and looked over it, here is what he found... He has already fixed the problem for me and has added a thermostat output function all for free, he's popping it in the post on monday also so ill have it back early next week. Very happy with the quick and professional service he has offered. This is a link to the guys website, if you are in need megasquirt ECU i cannot recommend him enough... Here. Top class guy.
