TrumpetRhapsody Posted September 2, 2008 Share Posted September 2, 2008 I searched around quite awhile looking for talk about doing this, but I probably wasn't wording it right. Didn't find much. I have a 280zxt wiring harness coming in this week, and as such I've been reading and re-reading the 280zxt to S30 wiring swap, and it seems to cater more towards a swap into a FI 280z. I have a carb'd L28 260z, of course with the stock transistor ignition system. My question: Is there a way to bypass the ignition functions of the turbo ECU, and just have it run fuel to the injectors. This would leave the stock transistor ignition system to control spark. This would allow me to run this setup on my non-CAS early L28 much more easily. Otherwise, I have to get the turbo coil, a turbo dizzy for the CAS or swap in my L28ET block, etc. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted September 2, 2008 Author Share Posted September 2, 2008 http://forums.hybridz.org/showthread.php?t=83971&highlight=FI+transistor+ignition Found this old thread talking about installing a MSD igntition system on a 280zxt motor, which is along the same lines as what I'm trying to do. AKA use something other than the ECU to control spark, but keep the ECU working. That gets me closer, as it sounds like this is possible. Now for how to go about doing it... Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted September 2, 2008 Share Posted September 2, 2008 Why don't you want the ECU to control spark? Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted September 2, 2008 Author Share Posted September 2, 2008 Because I'd need to either swap to an engine with a CAS on the crank, or find a (often expensive) CAS dizzy, AND get a turbo coil. This is supposed to be a cheap holdover till I can afford megasquirt. Don't want to buy twice. I just happened to snag a turbo wiring harness for a killer price. Hate to leave it laying around, but I don't want this to get any more complicated than it already is. My 260z controls the spark just fine. Bypassing the ECU's spark control would take alot of headache out of wiring it up in my case. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted September 2, 2008 Author Share Posted September 2, 2008 Doing more reading... Looks like I'm at the very least going to need a turbo igniter to send the coil signal to the ecu so it knows when to fire the injectors. Anyone have some input? I feel like I'm talking to myself here . Quote Link to comment Share on other sites More sharing options...
RDusel Posted September 2, 2008 Share Posted September 2, 2008 Chris, The turbo "igniter" is just a switch to interrupt the power to the coil and create the spark. It gets it's signal from the turbo ECU, it does not feedback to the ECU. Unfortunately I can't think of any way that you can do without the CAS as this is what creates the pulses that tells the ecu when to fire the injectors and trigger the igniter for spark. The ECU is looking for a particular pulse train and uses the speed of the pulse train to determine engine speed and combines with air flow reading to calculate the required fuel. The older style transistorized ignition just gives one pulse when each cylinder is going to fire and the N/A ECU averages this to determine engine speed. If you tried feeding the output of the tranistorized ignition into the ECU I'm not sure what would happen, might work or it might over-inject or under-inject the motor. It would be far easier to just get a CAS dizzy then spending hours testing to see what would happen. Hope this helps. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted September 2, 2008 Author Share Posted September 2, 2008 Ah, good, thanks for the info. Yeah I was wondering what would happen if I used the transistor as the input. I might try it, but you're right I should just plan to get a turbo dizzy I suppose. If anyone else has any ideas along these lines i'm open. Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted September 4, 2008 Author Share Posted September 4, 2008 Bump. Still not ready to buy a dizzy. Wiring harness is in the mail, so I guess I can always just try it. Any help or suggestions would be great though. Quote Link to comment Share on other sites More sharing options...
Zeerari Posted September 5, 2008 Share Posted September 5, 2008 Another Arkie l28et swap, yeah! I just glanced at the service manual and it says the turbo dizzy outputs 1 pulse per degree and has a TDC detection circuit so it sounds like you are attempting the impossible short of building a custom circuit to multiply the pulses AND somehow detect TDC (crank sensor). Certainly possible and would be a good design project but even my EE brain says it would be easier to build Megasquirt You can get $150 on ebay for your harness and ECU (and maybe something for the 260z dizzy and controller?) and that about covers the cost of the MS2 kit. You'd still need a few more items (speaking from no experience here) but I think that'd be a better investment than a zxt dizzy. I'm planning to head that direction soon after I get mine done (maybe this weekend, yippee!) since it's supposedly good for 50 hp right out of the box For what it's worth, just saw this on ebay: http://cgi.ebay.com/ebaymotors/DATSUN-280ZX-81-83-DISTRIBUTOR-TURBO-IGNITION_W0QQcmdZViewItemQQ_trkparmsZ72Q3a552Q7c39Q3a1Q7c66Q3a2Q7c65Q3a12Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem160278964903QQitemZ160278964903 Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted September 5, 2008 Author Share Posted September 5, 2008 I've got my MS II and all the goodies priced out to about $1300 when all is said and done. I may just get a turbo dizzy for now and try it. Then sell it all later. We'll see. Quote Link to comment Share on other sites More sharing options...
Zeerari Posted September 5, 2008 Share Posted September 5, 2008 Wow, I know little things add up but that's more than I'll have in my entire swap I guess I need to look into it further because my mental list was not nearly that painful. Good luck with the swap and hopefully I'll have a first-fire video to show off by Sunday Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted September 5, 2008 Author Share Posted September 5, 2008 Haha, nah it'll be quite awhile. The bodywork will be this weekend. I don't even have the harness yet. One thing making it expensive is converting to EFI from carbs. New fuel pump, new efi, new fittings, possibly new hardlines, etc. Quote Link to comment Share on other sites More sharing options...
Six_Shooter Posted September 7, 2008 Share Posted September 7, 2008 I don't think I spent that much on the EFI swap, at least I hope not. I didn't use MS, but that seems like a bit much, unless you are going absolutly new on everything. I'm sure that price could be cut down, even if you were to use some some stock/used parts for now. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.