Bernardd

All the sensors effect timing to some degree. The afm and airtemp inside the afm along with the cas rpm signal are the heart of the matter. It could be that inside the afm there is a small break. Or one of the enrichment tracks or resistors could be fubared which would throw part of the curve out of whack. Did you check the afm with an ohm meter as per fsm? If you're really ambitious you can check the resistance across each track. I have a turbo afm that I can check and compare. Bernard

You'll have to make a custom cas wheel. Each cylinder window will have to be about 50deg's in length. And you'll have to adjust it to go high 5 degrees before max desired advance (360/6cylinders=60 degrees max advance)and go low 5 degrees btdc. (I've got 45deg as max advance in my z31ecu) This is to provide a 5deg starting advance when cold. Our cas already goes high when the window crosses the diode so all you have to do get a custom wheel. Then you have to deal with providing dwell for the coil. You may be better off with a N/A dizzy. I think it provides dwell in the ignition module but I have no idea what type of sensor is inside. Or use the N/A ignition module to provide dwell by externally mounting it. I have no idea what type of voltage or current it wants to see prior to firing the coil tho. I'm patiently waiting for someone to come up with solutions to these problems. Bernard

The idle voltage at pin B on the maf should be over 2.2. Make sure it's the same at pin 31 on the ecu. Pin B at maf should be 1.6 at key on. Double check your grounds at the maf. When you install the known bad maf, the car should run the same with it connected or disconnected. It should make no difference. If the maf is out of wack the ecu ignores it. Did you do any work on the car recently? BOV?

The flapper door/stock efi is complete dung. I got so flustered with it I changed over to the z31 ecu. No problems since. It's even got built in diagnostics. I guess that doesn't help solve your problems. It seems to me that a common thread here is that all the cars with problems are not stock efi or turbo cars. I would suggest checking to make sure everything is grounded properly. I would also check to see if the shielding from the afm and cas is grounded in the harness. And disconnect the knock sensor. It's useless anyway. What kind of mods were done to the harness during the install?

Nice to hear other people have the same budget minded approach as I do. On to your questions. The air temp and Afm combine to tell the ecu the mass of the air being ingested. Same thing as the maf on the z31 eccs only rudimentary. Hts provides an enrichment to engine when cold. The lower the resistance the higher coolant temp= less fuel. I installed a switch to add 5k resistor to the circuit at wot. Didn't notice any increased power. o2 sends a voltage to the ecu telling it to correct for a 14.7 afr. If you disconnect it completely the car should run fine. Or get a new one. Tps tells ecu the car is off idle. SleeperZ is correct in that it's a table (at least in the z31ecu it is) The reason for the 3rd terminal is that's the way bosch makes 'em. In later model Nissans the tps is used as a tranny control input. The ecu combines the afm and rpm for determining engine load. At about 4500rpm the afm is fully open and the ecu uses rpm only. Inside the afm is a small circuit with enrichment resistors. You can easily customise acceleration enrichments by changing the values. I've chosen to use the z31 ecu along with an eprom burner to make my own custom maps for larger injectors. So far everything has cost around 200 dollars canadian.(not counting injectors) Cheaper yet would be bypassing air around the afm and/or tampering with the spring (inside afm) is no cost at all, when using larger injectors. Hope that helps, Bernard

Hey, I'm still interested in the MS'N'S. There are some problems that I've been kind off half heartedly been trying to figure out. 1. You need a signal 50 deg btdc to go high and then go low 5 degrees btdc. I have not checked yet to see when the signal from the cas changes. I have some scope shots of the signal if you're interested I can send them over. 2. You'll have to use some type of ignition module as the MS'N'S code doesn't provide for dwell. A few of the guys have been using gm hei modules to achieve this. I don't know enough about these units to know how they will fit into our systems. I believe one of the guys on the list has a version 1 board working. This is the board I have. I'm growing weary of fooling around with the z31 ecu after blowing one headgasket I'm beginning to appreciate the job JWT does a lot more. (Picture moi eating crow). Perhaps I can put my test bench to some use....... Bernard

I'm Otay Are you going downtown for the big burnout dealy?

And just how many Z's do you have? The stockers are 260cc or 270cc depending on who you believe. Bernard Southeast of Wpg.

Nice stuff Brad. I was out last night cooking some rice. You gotta call me one of these Sunday's so we can hook up. Bernard

So if I enter 30 as the base and 43 as the new fuel pressure and 35 lbhr as the injector rating here http://www.csgnetwork.com/fiflowcalc.html you are running 41 lbhr or 440cc injectors with your new fuel pressure. Correct? Or are you setting 43 psi with the vacuum hose off which would change the base to 36 psi at idle? Do you have any idea what the injector duty cycle is on a wfo run? EGT's? Maf voltage? I've got my fuel enriched as much as possible and I still can't go over 15 psi without retarding the timing drastically. That's with 91 Octane crap in the tank. Bernard

I've got a pic of a setup that a buddy is working on. I have no idea how to post it I can send it to someone if they want to post it. Bernard

Way to go Cody. What are the specs on your setup?

Yo' date=' If you watch your O2 waveform in real time on a lab scope as I was doing, its pretty instantaneous and usable information.[/quote'] I have access to a fluke scope. I can connect this and go for a run. What am I looking for that'll tell how rich or how lean? Bernard

I got it now Bernard

how come I can't see the dyno graph? Sleeper, can you email it to me?

Add a pipe that goes from before the afm and bring it back to the intake after the maf and before the turbo. You'll probably have to cut the rubber boot behind the afm and add a pipe to accomplish this. Go to Autospeed.com and do a search for Larger injectors. They have some other ideas and photo's. Zya's idea would be easier to work with and probably give you a better result. Bernard

I've been where you are now. If I had to do it again I would simply use SleeperZ's idea and go for a bypass pipe around the afm that increases the air flow to the manifold the same amount as the new injectors are larger. 370cc injectors are about 35 percent larger. Measure the area at the afm opening and increase it by 35 percent with a bypass pipe. I've done the "tighten the spring in the afm" and it's difficult to get right without a dyno or wideband. And upgrade your fuel pump. The stocker isn't good with the bigger injectors. Bernard 83 turbo 86 "Romtuned"ECCS

That's a hell of a deal Alex. Problem is I just had my turbo rebuilt. I'll probably sell it and upgrade from there. Bernard

Way to go. Are you tweaking the fp? I'm about ready to hit the dyno with my mine as well. Bernard 83 turbo 86 "Romtuned"ECCS

Perhaps I spoke too soon. The new code for megasquirtnspark doesn't have any dwell calculations in it. Your supposed to a saab ignition module with it. It may well work with NA distributor as well. It must have the dwell built into the module as timing isn't run by ecu. Bernard

Any chance I can get the specs? What should/would one pay for such a service?

It uses the output for the fast idle to trigger the coil. It's the squirt box with slightly different code. No need for two boxes now or any ford ignition parts.

Now they've got Megasquirt'N'Megaspark in one. This is what I've been waiting for over a year. As soon as the code is made available I'm in. Bernard

If you're getting more than 5vdc at idle your maf is shot or it needs adjustment. Is the adjustment screw beside the connector exposed? Or has it been tampered with? On second thought I'm not sure if the idle mixture screw can adjust that much.

Use lead with a paper clip into pin 31 at ecu and the also connect to chassis for ground. Or the B pin (I think) to ground at the maf. At key up the output of the maf should be the one that reads 1.6 volts or so to ground.