Bernardd

TBS: Merely changing the injector constant won't work. More reverse engineering is required. The 86 turbo bin file is available on the inflame site. The maf is easily changable in the code. All the Nissan maf vq maps are available. The stock maf for the vg30 engine was used by JWT on the old 280zx turbo conversions, they changed because of the failure rate of the stock maf and the cost of replacement. The ford maf they use is made by Hitachi which happens to be the manufacturer of Nissan maf's. I not sure yet but I think it's got the same calibration as the 300zxtt maf. I'm getting a copy of a bin file that uses the ford maf soon. I've got a harness conversion halfway done to use the Maxima ecu with the 280 wiring. This ecu should be a little easier to deal with as all the chips on the board have data sheets readily available.

If you're interested in modifying the rom in your Nissan ecu you should read this:http://members.optushome.com.au/silent8ob/ecu.htm This document refers to an ecu that is based on the Hitachi 6303 cpu. The vg30et ecu is based on the Hitachi 6802. The two ecu's seem to follow the same code structure. One problem with the vg30 ecu is that rather than using backup tables it has a series of checks that keep all variables close to stock. By that I mean it doesn't easily allow one to change, say the injector constant for larger injectors @ $BF2B-C and tune away. There are ways around this with the tp scales (load scales) and on the main fuel map, but it is easy to send the ecu into a fit and getting erratic pulsewidths. As far as my first reprogram went: I was able reburn no problem but I wasn't able to produce the result I was after. I haven't done any work on this for about 2 months now but I'm going to start again shortly.

The info on that page is stuff that myself and the owner of the page (Matt) have been gathering and working on for about 6 months. I've actually had the Romeditor on my pc for about 3 years, I just didn't know what I was looking at. I've tuned my ecu somewhat but I'm running into problems with my newly rebuilt tranny so I haven't gotten into it as far as I had hoped to at this point. All the info needed to tune a Nissan Rom is on that page or linked to it.

I may be able to get a board(s) assembled for a fellow Zheads for a few bucks. Auto tuning is also available for the reg MS board although I don't think it's as advanced. I think it only tells how far and which way to change values, it doesn't do it for you while driving. Mudge: there's a link somewhere on the MS page to an order form. I think everything or most parts come from digikey. Bernard

Link to megaspark http://www.aracnet.com/~hafner/MegaSpark.html Nathan: Is your maf reading 5 volts at 12psi? You may have to change to a mufstank maf. And I'll want 100 bux for burner + shipping. Let me know if you want to try some code. I can burn a couple of chips and send them out. Bernard

Heads up for the megasquirt guys. There is now a complete standalone, diy efi/ignition controller. The turbo cas is setup perfectly for use with the Megaspark. I have to verify the voltage output to the transistor is the same from the megaspark to the transistor as what the stock ecu sends to the transistor. Maybe someone knows. I've got a megasquirt built and ready to go, I was waiting for an ignition setup. All the stock temp sensors can now be used, with only an IAT needed. I have a Maxima tps (bolts on) and that's it. Programmable (realtime) efi for 200 bucks or so.......WOOOOHOOOO Anyone want my z31 setup c/w eprom burner and all the info?? Bernard

So your getting spark? Have you got voltage across the injectors with key on? By that I mean one side of injector to grd. Could be ecu. I've got one in the garage. It your's for shipping if you need it. Can you remove the cas, then turn on key, have someone test input pin on ecu, or harness, while you slowly turn cas. I think it's 0-5v. I'll check tonight.

Injectors not firing?? Fuel pump not turning on??

No module on zxt. Timing is ecu controlled. Ecu sends signal to transistor to allow voltage to the coil.

He's still got the car. I live just outside of Winnipeg. Fly here drive back. I can test the engine for compression and do a leak down if you're interested. Bernard

I'm not buying the car. The above post is just a heads up to someone who is planning on doing such a swap. Bernard

Guys, a co-worker is selling his Supra (89) in spring. The car is rusty but not abused. I would go so far as to say he drives like a granny. It's got around 270 k's on it. He only wants around 2k canadian for it. That's around 1400.00 USD and you can drive it home. The only issue is that it has an idle problem. Oh yeah, it's a 5spd. Bernard

Warren, make sure you have power at the following pins: 114, 27,35 and I believe pin 9 is the start pin. I just finished wiring up my ecu test bench and got caught out by the 27, 35 pins. Both my 85 and 86 ecu's light up the lights with the key on. If you need more help let me know. Bernard

Let me know if you guys are doing a dyno session. I gotta get my new turbo, eccs setup dialed in. Bernard Winnipeg

If all you want is to control larger injectors you don't need either the z31 eccs or the speedsensor. Get a pot type Maxima or 240sx tps. They have the idle switch and the pot tps in one unit. I would rather get the www.perfectpower.com unit as it can control the timing and you can use it to control extra injectors as well. And you wouldn't need to change the tps. It uses the afm signal to change the pw. I think it's cheaper too. my .02 Bernard

The math is what I wasn't sure about. What I'm doing is building my own 300zxt to L28ET ecu conversion. At or just above idle are the only points I can test right now, but I can retune the entire fuel curve for larger injectors, larger maf, rev limit, timing etc. Bernard

The reason for me asking the question was to determine what cc injector I could use with the new settings in the ecu. I can lower the duty cycle further but only if I start messing with the entire load calculations and I don't want to do that at this time. If 270cc inj's have a 7% duty cycle @ 800 rpm, what cc inj would flow the same amount of fuel at 4.2% duty cycle? Is it a linear relationship? all other things being equal. I probably should have worded the question this way in the original post. Bernard

So for my testing purposes I have decreased the fuel flow by X % equal to the X % reduction in duty cycle? I have not changed anything as far as vacuum or load the engine is seeing and the rpm is always 800. I should probably borrow a scope and find out exactly how much it changed.

Ok so if I use this formula 120000/rpm it'll give me time per revolution? 120000/800=150ms per cycle. 7% of 150 = 10.5ms pulsewidth. And a 4.2% dutycycle gives me a 6.3ms pulsewidth. Does that make sense? Bernard

Can someone with the JWT ecu measure the duty cycle at idle?

Can someone explain to me the relationship between pw and dutycycle? I have found a map that changes the duty cycle but I'm not sure if the pw is changed by the same amount. I have the engine sim set at 300 ohms at the CHTS, idling at 800-850 rpm. I can change the duty cycle from 7% (stock) to 4.2% by changing this map. Bernard

The guy at this site http://imflame.ricetek.net/~darkhalf/eccs/eccs.html says it's 160hz. Bernard

cool program for factory z32 ecu's http://300zx-twinturbo.com/conzult/index.html

Randy, what kind of power are putting out? I'm trying to decide if I should rebuild/replace my auto or convert to the n/a 5sp lying in the garage. I'm going to a t04b hybrid turbo that I can push to about 325-350 hp. I don't think a clutch is made to hold that kind of power for the n/a flywheel. Just wondering what your setup is doing for you. Bernard

Shipping would be a killer from Canada!!