darrencnz 10 Report post Posted October 20, 2014 Hey guys, I've now made an amatuer mistake.... When i sold the old m20b20 motor out of my E30, i got rid of the entire loom as well and forgot (didn't know) i'd need to relay box that attaches near left front suspension strut for the DME and the fuel pump. I went to start it on Saturday and realised my fuel pump was turned on as soon as i attached the battery, i knew at this point something was up, i turned it over anyway and did nothing at all so i did a little research and it appears i am missing that relay box which i should've kept. Please let me know if anyone has one they can sell me, i understand it has 3 relays, can anyone tell me if i need all 3 or just the main DME and fuel pump one? i am assuming this is my problem... PM me Darren Quote Share this post Link to post Share on other sites
e30ftw 396 Report post Posted October 20, 2014 It won't be. It's part of the m20 engine loom. The m52 loom is different and has it's own relays in various places. Fuel pump should prime when key is turned to ignition. Was the key at ignition when you connected battery? Quote Share this post Link to post Share on other sites
darrencnz 10 Report post Posted October 20, 2014 It won't be. It's part of the m20 engine loom. The m52 loom is different and has it's own relays in various places. Fuel pump should prime when key is turned to ignition. Was the key at ignition when you connected battery? Na, that's the thing... It's on as soon as the terminals are connected, key off... I don't recall the old setup from the m20b20 so I don't really know, my mate suggested there may be some kinda relay which made sense but we were just guessing... The m52 loom does have 2 relays on it but cos I never saw it connected to anything when I bought it, I have no idea what they are for and I can't really find anything online that has any info about that specifically... Quote Share this post Link to post Share on other sites
darrencnz 10 Report post Posted October 20, 2014 Here's a pic of the relays, there's also a red wire that you can see poking out at the top that has been cut so I need to look at that. Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted October 20, 2014 M20 fuel pump wire is green/purple from memory, I assume the M50xx system is the same. Can't recall locations of parts on the M50xx though Lack of relay will not allow the pump to work, not work all the time. Your best bet is probably to give it to a sparky to check for you Quote Share this post Link to post Share on other sites
e30ftw 396 Report post Posted October 20, 2014 Is that other wire a ground? Have you made sure all the loom grounds are grounded? That is super weird though, sounds like ECU is getting power from somewhere. Which wiring connector did you use / diagram. Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted October 20, 2014 ^^^^ Looks like OEM wire. If so - being red wont be ground Quote Share this post Link to post Share on other sites
darrencnz 10 Report post Posted October 20, 2014 I'm not really sure, I'm not connection up things that I'm unsure about. I thought it could be a ground too but not 100% Yeah everything's ground correctly, the wiring diagrams I've looked at all say the same thing and all the wire colours were exactly as the wiring diagrams said they were. C101 pin 13 purple/red to x20 pin 13 green/purple Will get everything else sorted first and then send it to someone to sort out, it won't be much, I'm sure, just someone that's familiar with it... Electronics just ain't my thing and my time is more valuable spent elsewhere, I'll leave it to the pros. Quote Share this post Link to post Share on other sites
polley 916 Report post Posted October 20, 2014 Brown is ground. Purple / red dosent sound right. All the ones I've done have been green/ purple on both sides. Quote Share this post Link to post Share on other sites
darrencnz 10 Report post Posted October 21, 2014 Brown is ground. Purple / red dosent sound right. All the ones I've done have been green/ purple on both sides. Ill post the diagram i used, i have found a few others as well and they all say the same thing so i assumed this was correct as all the wires and colours they say were correct to the pins etc... I just dont have them with me at the moment but be interesting to see what others think... Quote Share this post Link to post Share on other sites
