AZGhost Posted November 4, 2012 Share Posted November 4, 2012 (edited) Ive decided to get rid of the EFI system for my 76 for the triple weber carb setup. I have purchased a rebuilt high compression motor (p90 w/ F54 block 10:1). However, when it comes to the conversion process I have some questions. In regards to the distributor, it seems like you have to do some special work to this to make it work with the carb setup? Does anyone have experience with this, and can point me to more details as to what exactly needs to be done? To clarify, its an electronic distributor now since the FI system, but with the carb setup, its not going to be. So what do people do in this process? Keep the same distributor but modify it, or do you just go to another distributor all together? I know it seems like a simple question, but I have found way too many answers on this to get a solid answer. I appreciate any help. Thank you! Edited November 4, 2012 by AZGhost Quote Link to comment Share on other sites More sharing options...
z-ya Posted November 4, 2012 Share Posted November 4, 2012 Ive decided to get rid of the EFI system for my 76 for the triple weber carb setup. I have purchased a rebuilt high compression motor (p90 w/ F54 block 10:1). However, when it comes to the conversion process I have some questions. In regards to the distributor, it seems like you have to do some special work to this to make it work with the carb setup? Does anyone have experience with this, and can point me to more details as to what exactly needs to be done? To clarify, its an electronic distributor now since the FI system, but with the carb setup, its not going to be. So what do people do in this process? Keep the same distributor but modify it, or do you just go to another distributor all together? I know it seems like a simple question, but I have found way too many answers on this to get a solid answer. I appreciate any help. Thank you! You don't have to do anything to the distributor or ignition system. Quote Link to comment Share on other sites More sharing options...
AZGhost Posted November 4, 2012 Author Share Posted November 4, 2012 You don't have to do anything to the distributor or ignition system. Well thats a relief... Because this guy had a whole long list of things to setup for the distributor to make it work right. http://datsunzgarage.com/weber/ Quote Link to comment Share on other sites More sharing options...
NewZed Posted November 4, 2012 Share Posted November 4, 2012 The guy in your link is talking about modifying the timing advance curves. The distributor will "work", triggering spark from the coil, but it may not be optimum, depending on how you want the engine to run. Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted November 4, 2012 Share Posted November 4, 2012 This was taken directly from the page "While a stock ignition will work with Webers a high performance ignition is highly recommended to manage the extra fuel mixture they supply. If you have a 240Z distributor I suggest replacing the points with a Pertronix unit paired with a MSD 6A or similar. If you're lucky enough to have a 1976-83 280Z(ZX) distributor these can be easily wired into a MSD to create a full electronic ignition." So yeah your dizzy will work fine. I don't see anything about a list of things needed to set up the dizzy. He actually had a 240z originally with a points dizzy, and upgraded to the 280zx E12-80 dizzy. He does however talk about locking the dizzy to get the most out of the carbs, as NewZed mentioned. That is far different then getting it "just to work". Quote Link to comment Share on other sites More sharing options...
luvemfast Posted November 6, 2012 Share Posted November 6, 2012 I've got triple Mikuni's in my factory EFI car. It's as easy as take off the EFI gear and put on the triples. I have purchased a rebuilt high compression motor (p90 w/ F54 block 10:1) Are you sure its high compression? It would need domed pistons or welded chambers. As the P90 heads have a big chamber, due to being made for turbo application. Quote Link to comment Share on other sites More sharing options...
AZGhost Posted November 14, 2012 Author Share Posted November 14, 2012 yes, flat top pistons with a shaved head. Decided to go another route with an electromotive kit for the ignition. The XDI setup, along with triple 45's properly jetted all from top end performance. Steve is a great guy! Quote Link to comment Share on other sites More sharing options...
AZGhost Posted November 20, 2012 Author Share Posted November 20, 2012 So Im about ready to drop this new setup into the car this coming turkey weekend... But I have a few other questions. Looking at other peoples engine bay pix, there is no "fusable link" area. Before I start cutting the harness (cringe), is the fusable links no longer necessary? I plan on hacking off the coil side cables since its an XDI system, as well as EFI cable off the main cable as well. I did some searching, but really couldnt find anything related to what's no longer needed on the existing efi harness that can be cut off when going back to a carb setup. Also the water temperature housing block has a bunch of sensors on it that I dont think are needed anymore as well that dont need to be hooked back up? Anyone have some references or have gone through this process to know? Thanks in advance! Quote Link to comment Share on other sites More sharing options...
AZGhost Posted November 21, 2012 Author Share Posted November 21, 2012 So asking around at some Z shops, seems this is easier than I thought. Pull cable from ECU, pull ECU out, and then cable harness from ECU comes out. Whatever is attached to the cable harness can go. Piece of cake.... Quote Link to comment Share on other sites More sharing options...
Ben280 Posted November 21, 2012 Share Posted November 21, 2012 So asking around at some Z shops, seems this is easier than I thought. Pull cable from ECU, pull ECU out, and then cable harness from ECU comes out. Whatever is attached to the cable harness can go. Piece of cake.... That should be about it. The EFI harness ties into the main harness with two "clips" hear the battery. This is the EFI power. That wraps around the engine bay then splits into the ECU output and that is about it! Should be able to pull it all out without any cutting at all! Still totally need the fusible links though, they power the ignition circuit and master power for the fuse block. Post some photos when you drop it in! Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted November 21, 2012 Share Posted November 21, 2012 It IS that easy. Only other thing you'll need is a decent fuel pressure regulator. I'm running the stock EFI pump with an Aeromotive FPR and it works like a champ. I suppose you could go with a low pressure pump, but you'll likely need a regulator for that too - so just buy a regulator that can drop to 3.5psi and you'll be off to the races. Quote Link to comment Share on other sites More sharing options...
Ben280 Posted November 21, 2012 Share Posted November 21, 2012 Aeromotive makes some great stuff! Anybody have a Pro/Con on a "deadhead" setup for delivering fuel to the carbs? I.E. no return line? Quote Link to comment Share on other sites More sharing options...
2eighTZ4me Posted November 21, 2012 Share Posted November 21, 2012 I ran the return line. Just plumbed straight into the stock return line. Not so sure you'd want to run a deadhead setup if you intend to use an EFI pump. Not sure what the ramifications would be, but it would seem to me that it'd burn up the pump. A low pressure pump - not so much - but a high pressure pump.....hmmm - a little leary on that one. Course, I've been wrong before - my wife tells me that all the time! Quote Link to comment Share on other sites More sharing options...
Ben280 Posted November 21, 2012 Share Posted November 21, 2012 Cool! Sorry for the thread-jack AZGhost! Quote Link to comment Share on other sites More sharing options...
AZGhost Posted November 22, 2012 Author Share Posted November 22, 2012 (edited) Ah no worries Ben. I purchased a low volume fuel pump thats supposed to be correct at maintaining the 2.5 to 3 psi so no pressure regulator is needed. Im told volume is needed, not pressure with carbs. Ill be going 'dead head' too. The aeromotive stuff is awesome.... I got the aeroquip fittings in black/silver too, which was a major pain to find, but pierce manifolds sells em along with a direct bolt on kit for triple webers. Kinda pricey tho for the kit. So the fusable links needs to be kept? Every picture I have seen of an engine bay with the triple webers, there is no fusable links assembly anywhere I can see. Are you absolutely sure its necessary?? I guess I will find out soon enough Friday when I can work on everything again. Headers came in yesterday, so I had to mock it up. I got side tracked of needing to take pictures of the linkage.... ooo shiny! Edited November 22, 2012 by AZGhost Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 22, 2012 Share Posted November 22, 2012 Bit of advice on Aeromotive, like Harbor Freight, pull it apart and make sure it's clean & assembled properly. Quote Link to comment Share on other sites More sharing options...
Ben280 Posted November 26, 2012 Share Posted November 26, 2012 So the fusable links needs to be kept? Every picture I have seen of an engine bay with the triple webers, there is no fusable links assembly anywhere I can see. Are you absolutely sure its necessary?? I guess I will find out soon enough Friday when I can work on everything again. Sadly, yes you do need to keep the fusible links (seeing as you posted this a few days ago, you may have already realized this!) The fusible links control headlights, ignition, alternator charging and on the '76 one of them is for ignition and the EFI system. I suspect however, people who go through the trouble of converting the EFI system to carbs take the time to convert the fusible links as per the link below: http://atlanticz.ca/zclub/techtips/fusiblelinks/index.html follow the instructions in that guide and you can turn that ugly fusible link array into a nice shiny new fuse box setup! a good audio shop should have everything you need. Quote Link to comment Share on other sites More sharing options...
AZGhost Posted November 28, 2012 Author Share Posted November 28, 2012 Hey Ben, I found that as well last week, it looks like good info. Ill keep the fusable links on for now. I got a lot of other stuff to worry about and that mod seems simple enough where I can do it later on down the road... Quote Link to comment Share on other sites More sharing options...
Gollum Posted December 1, 2012 Share Posted December 1, 2012 Okay, so I've read through this thread on like 3 different occasions and finally it's bugging me just too much not to ask... ... are you SURE that's a 10:1 compression ratio engine? On a P90 that's a WHOLE lot of shaving, or even welding. OR it's dome pistons, which would require a custom P90 chamber shaped dome. OR.... It's a stroker... No matter which way we're talking about that's a solid 1.5+ of compression bump. That's a wee bit more than just simple shaving get you, and if you shaved a P90 that much I'd be worried about other details. Quote Link to comment Share on other sites More sharing options...
ram75280z Posted December 2, 2012 Share Posted December 2, 2012 Just save the head .080 & shim the towers. that will get you right around 10 to 1 it's described on the Datsun Z garage website Quote Link to comment Share on other sites More sharing options...
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