mrbcf
Parking Attendant
Posts: 10
|
posted September 14, 2002 07:43 PM
Need help with ZX12 ECU
I'm building a ZX12 powered car for SCCA (Sports Car Club of America) events. I've got the engine in using the stock fuel injection system and (mostly) stock wiring harness. But when I switch on the ignition, the fuel pump doesn't run, etc. The relay, pump, etc. are OK but the ECU is not switching the pump on. When I crank the engine over, the ECU does not appear to be firing the injectors or the coils.
Does anyone know if some of the things I have left off the wiring harness are really required - such as the dash unit?
I have left out the headlights, tail lights, turn signals, brake lights, oil pressure switch (I used my own pressure guage) and dash. I believe I have correctly wired around the side stand switch, starter lockout switch and engine stop switch since the starter works and will crank the engine over. I have the FI LED wired up and it works but does not show any fault codes. The "bike down" sensor seems to be giving the correct voltage.
Any thoughts on where I've gone wrong?
  
|
Doctor Jack
Novice Class
Posts: 31
|
posted October 29, 2002 10:50 AM
I had the same problem. I built my own wiring harness and ended up with the same as you. No fuel pump, No injectors or ignition. If I remember right the FI light would flash when cranking on it. well after two weeks of going over and over my harness I couldnt find any thing wrong. So I borrowed a buddy of mines bike and started doing voltage checks at the ecu. I found out that the gray wire at the ecu that comes from the ignition switch was a little lower voltage than mine. So I put A 69 ohm resistor on the gray wire to drop the voltage one volt. everything went to working and she fired up. So my guess is that the gray wire is a theft control wire and it is resistive. since I made my own wiring harness and all the wires are alot shorter I didnt have the voltage drop the ecu wanted to see. But Mine was doing exactly like yours untill I droped the voltage on the gray wire and everything went to working. I bet this is your problem. Let me know. I pulled most of my hair out to find this problem. also....If you want to get ride of the upside down sensor you can put a 330 ohm resistor from groung to the yellow/green wire.
Let me know
|
mrbcf
Parking Attendant
Posts: 10
|
posted October 31, 2002 05:25 PM
Yes, the resistor in the gray wire was the cure. Thanks! For now I have the bike down sensor filled with silicone but thanks for the resistor tip.
|
Doctor Jack
Novice Class
Posts: 31
|
posted November 01, 2002 01:09 PM
I just wanted to let you know I went through hell before I found it. They dont even talk about it in the shop manual. I wonder how many people are still scraching thier heads.
|
beansbaxter
Needs a life
Posts: 5911
|
posted December 22, 2002 02:52 PM
How did that ZX12 powered car turn out? Any pics??
|
mrbcf
Parking Attendant
Posts: 10
|
posted December 29, 2002 01:41 PM
The car is pretty well finished now. Of course there is always more to do. We'll see how it really turned out in the spring when the season starts. I have pics but don't have a place to post them. I could email pics if you *really* want to see.
|
frEEk
Administrator
ummm... yeah
Posts: 9660
|
posted December 29, 2002 02:38 PM
there's plenty of free image hosts available. i'v had luck with imagestation.com (sony's free image host)
|
mrbcf
Parking Attendant
Posts: 10
|
posted December 29, 2002 05:57 PM
Thanks, frEEk. Ok, let's see if we get pictures or little red x's.
First should be the monocoque during construction.
Next is the differential carrier being fitted to the frame. This is the clearest pic of the ZX12 engine.
Here is the engine in the finished car with rear body removed.
Finally, the entire car with bodywork on. Paint is actually a very dark purple pearl with silver stripes.
|
frEEk
Administrator
ummm... yeah
Posts: 9660
|
posted December 30, 2002 12:53 AM
damn, that's sweet!
|
ZHooligan
Moderator
Post Whore Extraordinaire!
Posts: 3829
|
posted December 30, 2002 01:15 AM
What kind of speeds will this car do with the 12 engine in it? And approx. what does it weigh? The car looks like a kick in the pants.
|
Doctor Jack
Novice Class
Posts: 31
|
posted December 30, 2002 01:48 AM
Heres Mine
|
Doctor Jack
Novice Class
Posts: 31
|
posted December 30, 2002 02:05 AM
mrbcf
Did you make that airbox. Do you want to make another one. Im still not pleased with mine. I had hell with it. The car looks light.
Mines 1100pds. But our rules say you have to be 1050 or above. And in dwarf cars you have to turn the motor sideways and use a car type
rear end with a drive shaft. Im the one that helped you with the wiring problem when you couldnt get her fired.. You car looks great and dam light. I bet she will fly. What are you planing on doing with it?
|
mrbcf
Parking Attendant
Posts: 10
|
posted December 30, 2002 07:40 AM
I haven't checked the top speed on this car yet but cars like this typically run 130 to 150 mph top speed depending on the track (how long the straight is). The car is 925 lb with everything except me. For roadracing, it has to weight 1200 lb with driver. Since I'm under 275, I'll have to add ballast for road racing. I mostly autocross (one car at a time against the clock) where the minimum is 1114 lb with driver. If I don't eat too much over the holidays, I'll need a little ballast for that too.
The machined pieces like the dry sump system and the differential and diff. carrier were made by Taggart Perf. Engineering. I built most everything else including the air box. It's a one off and was a real pain to make. I hope I don't have to do that again any time soon! I haven't had the car on a dyno yet so I don't know how well it works.
Doctor Jack, is your engine carb'ed or FI? This one uses the stock FI with a PCIIIr.
|
Doctor Jack
Novice Class
Posts: 31
|
posted December 30, 2002 10:38 AM
mrbcf
Its FI. Remember at the very begining of this post I was telling you I had the same problem you did, No fire , No injectors, No fuel pump. Untill I found the majical gray wire voltage drop. I dont have a PC3r yet, But I plan on putting one in before next season. I would really like to know about your dry sump system. It looks like Im going to have to get one. I dont have enough ground clearance. I read here that muzzys was planing on putting one out.
|
mrbcf
Parking Attendant
Posts: 10
|
posted December 30, 2002 01:40 PM
Oops. For some reason I was thinking that dwarf cars had to use carbs. The dry sump uses a modified stock pan. About 4" of the stock pan is cut off (the deep part on the left side). A flat bottom piece is welded in. This piece also has the internal plumbing from an AN fitting at the front of the pan to the inlet of the stock oil pump. The scavenge pump inlet is on the left side of the pan and is hard piped to the inlet of the scavenge pump. The scavenge pump is a custom gear pump that is located between the stock oil pump and the water pump. The water pump is moved outboard about 3" to make room for the scavenge pump. The stock oil pump normally drives the water pump but now drives both the water pump and the scavenge pump.
I also heard from Doug Meyer at Muzzy's that they were working on a dry sump but I don't know when it will be out or what any of the details on it will be.
|
Doctor Jack
Novice Class
Posts: 31
|
posted December 30, 2002 05:49 PM
Did you have the scavenge pump custom built for you. Or is it made by a company for this aplication.
I see why you might have thought mine was carbed. The rules say no fuel injection unless it came from the factory with it.
|
mrbcf
Parking Attendant
Posts: 10
|
posted December 30, 2002 07:41 PM
The scavenge pump was custom built by Taggart Performance Engineering for me. It was all designed on a CAD system and then made on a CNC mill so it should be possible to have more made. I'm sure the next question is what it costs. To be honest, I don't know. I had a lot of other work done at the same time - the main thing being the whole limited slip differential / sprocket flange, brake flange, diff carrier, etc. assembly. I've known Ken Taggart a long time so I didn't ask for an itemized bill. If you want to talk to Ken about it, give him a call at 717-285-7348.
You're right about the rules - I missed the "unless it came that way" part. I would think the ZX12 is the engine to have in a dwarf car - are lots of folks using them or are you a pioneer?
|
Doctor Jack
Novice Class
Posts: 31
|
posted December 31, 2002 12:33 AM
Well I was planing on being the pioneer. I was one of the first to get one to put in a car. But I didnt get of my lazy ass to finish it in time. Now there are a few with the zx12 motors and thier doing great. They are the best engine to have since you cant have anything bigger then 1250 and FI is allowed if it came with it. It makes it the motor to have. I dont know if this will help you, But I went to the local auto parts store and found a small slave cylinder. I welded a peace of metal to the original clutch arm and hooked the slave cylinder to it. I then used a toyota master cylinder for the clutch pedel to hook to.. So now I have a hydrolic clutch instead of the cable. Works great......When season gets closer I will get ahold of your buddy and see about the pump. I can do the rest of the mods for the dry sump myself, But I cant come up with a pump. I was planing on using a electric pump. I hate to rely on a electric pump, Scares me!!!!!
|
mrbcf
Parking Attendant
Posts: 10
|
posted December 31, 2002 08:31 AM
I ran the original clutch cable from the clutch to the right side of the car where I have more room. Then I hooked the cable to a pull type slave cylinder from Wilwood. Attaching the slave directly would have been cleaner but I ran out of room.
|
frEEk
Administrator
ummm... yeah
Posts: 9660
|
posted December 31, 2002 11:10 AM
man, this stuff is invalubale for when i finally get around to stickin a 12 engine in my datsun (assuming i ever get around to it). ica nt wait to try it. figure i'll get it down to around 1500 pounds complete by the time i'm done. it's gonna rock! course, the interior will be fairly minimal, but that's a price i'm willing to pay. come to think of it, what do u do about getting more power out of the alternator? a bike one certainly aint gonna be enough for a car.
|
mrbcf
Parking Attendant
Posts: 10
|
posted December 31, 2002 12:05 PM
I'm not sure anyone has ever worried about the alternator. For racing purposes, it has never been an issue. You only need to run the fuel pump, injectors, plugs, ECU, tach, temp guage, an idiot light or two and tail lights (if the rules require them). My tail lights are LED so they don't draw much. Most of that stuff the bike had already and since I don't have headlights, I should be drawing less than the bike. Lots of guys actually remove the alternator and just run off the battery and recharge it between races (SCCA club races are usually only about half an hour long).
If you're talking street car, that's probably a different story - especially if you need a bunch of power to drive a stereo. Of course for a street car you have the little problem of reverse gear...
|
Doctor Jack
Novice Class
Posts: 31
|
posted December 31, 2002 03:03 PM
Nope. They make a reverse kit if your gonna turn the motor sideways and run a drive shaft. Also you can mount a car altenator to the rear end and put a pulley on the flange where the u-joint hooks to. A lot of drag racers did this.
|
frEEk
Administrator
ummm... yeah
Posts: 9660
|
posted December 31, 2002 05:38 PM
sweet! thx fer the tip. this is indeed for a street car. i'm not too huge on stereo, but i woudlnt mind having something decent. i was more concerned about the HVAC system & possibly needing a larger rad fan. for that matter, i'm thinking heat may be a problem. may have to use the whole rad as a heater core & just redirect the heat when not heating. was thinking to use a stock sized rad since the car will be more demanding of the engine, but maybe that would be overkill. guess a rad from a small car like a Firefly or sentra would do the trick.
i do have one serious concern about this whole idea, and thats whether the 12 engine is really teh right choice. i'm thinking a busa engine would prolyl be more car friendly just cause of the bugger torque & less clutch issues. my onl reason for using the 12 engine is cause i think it would be kinda neat having the same engine in bike & car. thoughts?
|
frEEk
Administrator
ummm... yeah
Posts: 9660
|
posted December 31, 2002 05:40 PM
oh yeah, reverse kit w pulley u mentioned, they got a website? that sounds like the ticket. tho i'm actually tempted to try mounting it in the rear to eliminate most of the driveshaft. tho by that point i prolly have too much rearward weight bias.
|
Doctor Jack
Novice Class
Posts: 31
|
posted January 03, 2003 08:22 PM
This place has a phone number you can call. They are showing a newer version they have now, But Im sure they still have the old one also.
http://www.jaxports.com/
|
|
|
HOME
NEW TOPIC