splking

hey guys, im new to the site but im hoping you can help me. i put a 13b efi in my mazda b2200 truck. when i pulled the engine out of the 87 rx, i pulled everything. i have the wire harness and computer and everthing else. some of the sensors and other things dont match up so i didnt plug them in, but the major things are hooked up. the problem im having is that i dont have any spark. the coils are powered the computer is powered. my question(s) is (are): is there something weird that needs to be plugged in that im missing. something like the stock instruments need to be plugged in or maybe like the motor needs fuel pressure or maybe something else. any information is greatly appreciated. im kind of at a standstill.


thanks
mike

NZConvertible

That's a cool conversion!
I can't think why you don't have spark, but what I suggest you do is go to www.fc3s.org and download the wiring diagrams chapter of the 86-88 factory service manual. Find the pages with the ECU wiring, and try to narrow down everything on the diagrams you have and haven't hooked up. Hopefully you'll pick up what's missing. Let us know how you go!

Dirtking

Check your grounds...like at the back of the motor. are the coils getting power, or a signal?

Keith

For ignition, there are 3 requirements. First, power to the coils. Second, timing signals from the CAS to the ECU. Third, a normally functioning and powered ECU to provide timing signals, which in turn are converted in the ignitor assembly (from 5V signal to 12V signal). Troubleshoot these until you find the cause of the failure.

Irv, Keith's dad

splking

you guys are freakin' smart. thanks. ill check these tomorrow night.

mike

HAILERS

The next three jpg are the outputs of a 87na at the ECU: Made a little error on this jpg, just ignore the top part where it talks about a *monitor*. Volt/ohm meter works just fine. This is for a 87model with a N332 ECU. I used this jpg along with the wiring diagram below to wire a N332 with cas and coil assys to work on a 82 rx-7. Did not do the fuel pump because its carb. car.

HAILERS

JPG:

HAILERS

ECU THREE:

HAILERS

ECU FOUR:

splking

Hailers!! your Awesome! thats exactly what ive been looking for. Thanks Man. Ill let you guys know how it turns out.

Thanks Guys
Mike

HAILERS

I see what could be a small problem if your using the fuel injection instead of a carb. Y0u said it was a 87, and there is where the problem might be. If that car used the low impedence injectors, you'll need to make sure that you have a *solenoid resistor* in line with the power wire to the injectors. If you have the high impedence injectors(about 12ohms) you don't have any problem. The cut off b/t low(2-3) and high(10-12) was in mid year of 87. You should just ohm across the two pins on one of the secondaries to see which you have. Its my understanding that you can whack the ECU if the solenoid resistor is not there for the low impedence. You probably already know that, but what if..... Like I said, I put a 87 ECU in a 82 just to run the ignition, nothing else, and it worked with the 87 cas and coils, so if yours does not fire, write back and I'll attempt to tell you just which wires I ran to the cas and coils from the ECU.

splking

thanks HAILERS, thats good info. im going to check it out later this afternoon. if i dont get it, im sure you'll hear from me tonite. i appreciate all the help.

mike

splking

Hey Hailers,

1 ?4u: i have everything plugged in. i checked the outputs off of the ECU. #3b reads 0V at Ign. switch on and 8.3V at starter cranking. Your sheet says it is suppose to have 1.5V or below at Ign. switch on and 12V at starter cranking. is this going to cause a problem?

2 ?4u
there is NO output out of the ECU to the coil packs. All 4 wires are dead. Is that because of the 3b wire, or do you think my ECU is bad?

splking

hey Hailers, any answers?

HAILERS

I'm pretty sure you are missing a 12v input. I'll look during my lunch period. I doubt the ECU is bad. I'll run to the house during lunch and copy the wires I have connected to the ECU I put in the 82 model from the 87. Just a 12v input missing from the key sw, fuse box etc. Give me a couple of hours. No schematic at work and they insist I WORK! EDIT: Could be missing a ground also.

HAILERS

About the 3B. Zero volts is just fine. Anything below 1.5 is ok. Did you have some 12v attached to the coils where it shows a BY or black and yellow wire????? On the 82 I just used the existing wire that fed the coils on that car. See the schematic that shows the coils. That B/Y wire needs 12v put on it from wherever, key, etc. On the coils the only wires that should have a voltage on them would be those shown a B/Y, black and yellow stripe. On my 82 I have the following wires: 1M, 1N,1P,1Q,1T,1U,1V,1X AND 2A,2C,2G,2R AND 3A,3G,3I,3J The car will run with these and no other wires as long as you are not running fuel injection. Some of those wires are grounds, and I do believe they need to be there. The 2A,C,G,R wires were to the tps. I needed the tps to make the ignition advance. I was going to also add the boost/pressure sensor when the weather arrives.They are also needed for advance for the ignition, I have been lead to believe.What are you using for fuel??? Fuel injection? If you are you'll need some more wires from the ECU. Once again, if you don't need anything but ignition, the above connections will do the job.

HAILERS

Seems you should have had something on 1U. Like you said, it says you should have approx 4.4 v. I'll check and see when I get home. The other three should be 0. Might ring the wires to the cas. N to P and T to Q. I'm a bit lost right now if you have all the wires I mentioned in the post prior to this one and have a switched 12v source going to the coils plugs BA-08 and BA-09.

HAILERS

I just got home. Pulled the plug off the Trail coil assy. This four wire plug has 5.1 v on the brown/yellow wire, 12v on the blue/red wire, and nothing worth talking about on the other two wires. So in ,my rush to judgement, I'd say you're missing one of the 12v inputs to the ECU. like pin 3J or 3I . Later. I don't think its the ECU. Just a missing 12v to the ecu. EDIT; In that first post I wrote today, you know to ignore where I said that the only wire at the coils that should have power is the Black/ Yellow. That was a goof. Should have power at the black/yellow and the brown/yellow and blue/red also(different plugs, but still to the coils).

splking

hey hailers, i just checked all of my wires. everything is good EXCEPT... the 3I wire. the key says that this wire is neither an input nor a output. the wire is b/w but mine got clipped up front. im not sure what it went to but mine is empty. is this suppose to hot? and if when is it hot? or is it a ground? like i said mine was clipped so i dont know what it did. let me know if you get a chance. thanks man.

HAILERS

You have to have 3I. EDIT: HOLD ON A MOMENT. I GOT THE PATH WRONG. LET ME FIND WHERE IT REALLY COMES FROM. I KNOW I HAVE 12V ON THAT WIRE, AND IT SHOULD COME FROM THE BATTERY, I JUST LOST THE PATH. ITS LATE. SORRY ABOUT THE ERROR. I'LL LOOK FOR A BIT LONGER. IT SHOULD BE A INPUT, JUST NEED TO FIND FROM WHERE. MAY BE TOMORROW.

HAILERS

OK. Back. I found my way again. Got the flu. It does come from the main relay. The feed into the main relay is a WL or white and blue wire, that originates at a 30s fuse in the MAIN FUSE, shown in that fpg I called ecu jpg five. The fuse is in the upper left corner of that schematic.

HAILERS

The path to 3I:

HAILERS

jpg

HAILERS

Bottom line is that 3I is a 12volt input and is needed. Its hard getting on this forum except early morning. once you get 12v on 3I, let us know if you now have any juice on the coil plugs.

splking

hey man, first of all i want to thank you again. second of all i really appreciate your help. and third of all IT RUNS!! what the heck are you doing up at 5am? i should have gotten to the computer last night to let you know. right after we got the spark going we hooked up the injectors and the fuel pump and it started right up!! i would have never figured it out without your help. thank you so much. just to let you know, i run the graphics dept. at a sign shop and if there is ever any decals you need for your car or whatever let me know and i will do my absolute best to get you whatever it is. i have the technology to do almost anything to do with stickers or signs so just let me know. thank you again HAILERS. your awesome!!

mike

sorry to hear you have the flu.