cygnusx1 Posted September 22, 2004 Share Posted September 22, 2004 Does anybody remember a few years ago there was a website where some mad scientist dissected the 280Z fuel injection system and actually documented each resistor and function on the ECU board. He showed how to "recurve" the factory ECU by swapping resistors on the ECU mainboard. He tested it all with a scope on a bench. Well, I don't know if that website still exists but I did print it out and found the information in my closet the other day. Would there be any interest here for that info? I should be able to scan it. Let me know. Quote Link to comment Share on other sites More sharing options...
Guest 2slo4u Posted September 22, 2004 Share Posted September 22, 2004 I would be curious. I've noticed some of the resistors are mounted up away from the main board, like they are made to be removed easily for some type of modification. Quote Link to comment Share on other sites More sharing options...
zcarnut Posted September 23, 2004 Share Posted September 23, 2004 This site has some interesting info: http://users.exis.net/~audserv/Injection.html I don't think the author used a Nissan ECU, but maybe the resistor references are the same. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 27, 2011 Author Share Posted May 27, 2011 (edited) Hey do I get a follow-up award with this one? http://forums.hybrid...post__p__896858 Post#14 Edited May 27, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
rsicard Posted May 27, 2011 Share Posted May 27, 2011 Hey do I get a follow-up award with this one? http://forums.hybrid...post__p__896858 Post#14 "The article was written about the generic L-Jetronic system". The L-Jetronic is a BOSCH fuel injection system! This discussion is FAR from where it needs to be. Most EFI systems have an embedded computer system wherein the fuel and ignition curves are contained in memory devices in binary form. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 27, 2011 Share Posted May 27, 2011 The JECS is BOSCH licensed technology. As the Japanese say "The Same, But Different!" Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 28, 2011 Author Share Posted May 28, 2011 (edited) "The article was written about the generic L-Jetronic system". The L-Jetronic is a BOSCH fuel injection system! This discussion is FAR from where it needs to be. Most EFI systems have an embedded computer system wherein the fuel and ignition curves are contained in memory devices in binary form. I don't get what you are saying? EDIT: Oh I see, you are saying that the info only applies to Bosch systems not the early Datsun systems. But oh, it does. These are solid state. Not much RAM ROM in here http://en.wikipedia....trol_System_Co. Edited May 28, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
rsicard Posted May 28, 2011 Share Posted May 28, 2011 The JECS is BOSCH licensed technology. As the Japanese say "The Same, But Different!" Tony: You are quite accurate. "Japan Electronic Control System Co., Ltd. ("JECS") was formed in June 1973.[1] It was a joint venture between Robert Bosch GmbH, Nissan Motor Co. and Diesel Kiki Co., Ltd.. It enabled Nissan to use Bosch's engine control technology, and gave Bosch access to the Japanese market. JECS later expanded to manufacture many other automotive parts besides EFI systems." Quote Link to comment Share on other sites More sharing options...
KunoZ Posted May 28, 2011 Share Posted May 28, 2011 Didn’t think 280Z/ZX's ECU's were reprogrammable. Not sure on the reason why just so I was told. I do know the Z31 ECU’s are though. The 88-89 Z31 ECU w/nistune is a good alternative for the L28 as well. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 28, 2011 Author Share Posted May 28, 2011 (edited) The early ECU's work by charging and discharging caps through resistor and diode circuits...old school stuff that I am not versed in. You can talk to them all you want but you can't program them. What you can do is change the way electricity flows around the boards to ultimately change the way the injectors pulse. You make these changes with a soldering iron and resistors. I have not tried it but I am sure it works. It would be fun to try but ultimately a modern EFI system has way more flexibility and is simpler to add bells and whistles too. Edited May 28, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 28, 2011 Share Posted May 28, 2011 If I opened a JECS box to do soldering, it would be to breadboard a MEGASQUIRT inside it and that would be the end of it! This electronic experimenter mentality is OK to a point, but for christs' sake the box is 1968 technology! It works to a point, but that point is so rigid and inflexible, and takes so much work to change why bother? The biggest downfall to a machinist coming into the field is that they think they can 'fix' everything. It simply doesn't make sense to spend $2500 to fix something that can be replaced for $68! Same for E-Sparkies and the JECS box---the reality is you can put that MS into your box, have it look just like stock, but FUNCTION on a par with at least mid 80's if not early 90's fuel loop correction and have an overall performance increase...not to mention self-adjustment via twin BARO sensors and an O2 loop. Unless I was restricted by class rules to use the JECS box, there is no way it'd use it for anything other than a STOCK car (and even then....that retrofit to Megasquirt makes for a BETTER DRIVING CAR! And it STILL passes smog out the tailpipe!) Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 28, 2011 Author Share Posted May 28, 2011 Come on Tony!!! Let's rig up a tractor trailer to haul this thing behind a Z with an umbilical cord running the injectors! Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted June 24, 2011 Share Posted June 24, 2011 (edited) While Managing Blue Streak, I had a 30,000 sq. foot warehouse full of ecus. I compared every bosch ecu sorting by connector and found many to be near identical to the nissan ecu from 1975 to 1983 non-turbo nissans with minor component differences from S30 to S130 applications. Of course, the tunes on the rom are different for each application but I ran a 1984 maxima with turbo bits bolted on at 5psi for about 30,000 miles without any issues on non-turbo injectors but I did use a 1982 280zx ecu and air flow meter which might have allowed for more fuel flow as it was intended for an engine .4 liters larger. The 280zx turbo ecus were the first in the newer nissan specific ecus that later ended up in the z31. This doesn't mean you can put a datsun ecu in a bmw 530I but many of the components such as injector and coil drivers are similar (darlington...etc). Edited June 24, 2011 by HowlerMonkey Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 25, 2011 Share Posted June 25, 2011 I know of at least one person who used BMW 3.0 liter engine ECU and all related components in his 240Z... for everyone looking on from the outside it looked like a Datsun System. Hell, I was the guy putting JECS ECU's into CORVAIRS in the late 70's and onwards. This was a VERY popular swap in the Corvair world to get EFI and remove the hassle of carburettors! But the technology is dated. The way I would put it is 'Apollo Technology'... Today you can buy 'Space Shuttle Technology' and directly attach it. So why bother with the older stuff? I mean if you are DEAD SET on using OEM components from some misdirected reliability thought...then this is all really old news. Guys who have been playing with EFI since the 70's (yeah guys, VW started mass production in 68, Datsun in 75... it's technology FAR older than most people think!) none of these parts swapping stories is anything new. STANDALONE (and more importantly MEGASQUIRT) changed the aftermarket world forever. No longer do you have to approximate and guess. You can tailor it EXACTLY. A Megasquirt V1.0 running the fuel only 8X8 tables will give superior drivability and equivalent emissions performance as a JECS box (with the added advantage of closed-loop operation which the first-gen JECS boxes didn't have!) The later versions incorporating 12X12 tables, fugabaoudit! Quote Link to comment Share on other sites More sharing options...
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