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Almost have the turbo running. What did I do wrong? :)


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I just finished installing my motor into my z:twisted: . Only problem is it does not have any spark. It has an 83' 280zxt ecu, distributor, and engine wiring harness. The engine wiring harness is hooked up too all sensors. Off of the no.2 plug I have the yellow solid wire hooked to a 12+ constant. The yellow w/white stripe wire to the power transitor. The black wire to a good ground. Also on the power tranistor I have a 12+ switched to the power transitor.

 

Over by the battery I have a green relay. Then I have a 12 gauge green and brown wire connected to the positive terminal. I then have about five 16 gauge wires just loose. There is a white, green, black w/white stripe and a few others. I am unsure what these wires do and think this is my problem. I have a volt meter but I am unsure if it can detect the rapid voltage that the ecu sends to the transitor. When I install my fuel cell and pump I will check if the fuel injectors are firing. That way I will know if my ecu is getting power. I have the stock 260z body wiring harnes taking care of the alternator, starter, and fuel pump. Thanks for your help.

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first find out if the ECU is getting power... and the coil..

 

then see if the car will turn on and test electronics...

 

then try starting it.. if it turns over and doesnt spark you can help source your problem...

 

if you turn the key and nothing happens it will give you more idea's...

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Well the car does turn over since I have the body wiring harness still attached. The transitor is getting a 12+ switched voltage but it is coming from the body wiring. I can not tell if the ecu is getting power. The other transistor wire yellow w/ white stripe is not getting any power even while cranking. Althought I am unsure if my digital volt meter has a fast enough refresh rate. I am unable to test if the injectors are firing since I have not installed my fuel pump or fuel cell. Thanks for you help.

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Sounds like you have it wired right.

 

In addition to PrO's suggestions.

 

You should get 12 volts when the ignition is turned on at the + side of the coil which also the conector of the ignitor that is perpendicular to the coil.

 

The signal out of the computer is difficult to see without a digital o-scope. I attached a picture of what it should look something like. This was from my 81 motor going into a bad ignitor, regardless the signal should look similar. The voltage is something like pulses over 10volts. A meter may see something like 2 volts for a short burst while it is cranking, depending on what type of meter you have.

 

The computer sends its output to the ignitor and at every pulse the negative end of the coil is connected to ground thus completing the circuit and pulsing the coil. The computer needs an input signal from the distributor to know that the engine is rotating. My problem was a bad ignitor. You could have a bad ignitor, coil, computer or even a bad distributor. Also make sure the ignitor is bolted to the body. It has no ground wire. Instead it is ground though the outer casing which is riveted to the coil bracket.

 

I found a cheap and easy was to check the ignitor.

 

Remove it from the car. Attach a meter to the blue wire of the ignitor and ground the other meter lead to the coil bracket. Using a AA battery and some wire, apply the + side of the battery to part of the ignitor where the yelllow w/ white stripe wire used to be connected. Every time the + side of the battery connects to the ignitor, the meter will measure a short or less that 2ohms.

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Guest bastaad525

agreed, it might be a bad ignitor, I had this problem once when I wired my MSD wrong and fried the ignitor, gave up trying to install the msd, then wondered why I still wasn't getting spark when I put everything back the way it was.

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Ok here is an update. My ecu green light never comes on. Not in the off position, on position, or starting. Does this mean that the problem is ecu isn't getting power? Or does it mean that ecu is not getting a signal from a sensor to turn the light on and to send a spark.

 

At my efi relay my brown wire is getting a constant 12+. The other three wires coming from the efi relay are not getting any power. My guess is that one of the wires is a switch 12 to turn on the relay but I am unsure of what one this would be. Please please help i'm about too burn the stock efi and sell a kidney and buy megasquirt.:twisted: I really don't have the money for megasquirt just yet so I would rather fix this. Thanks.

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the green light comes on as soon as the ignition is turned on and stay on. It goes off or fades during cranking.

 

I have another ecu you are welcome to if you need it. PM me with you address and I will send it out. It may have been off an automatic so I don't know if it will work 100% correct. I only ask that you pass it off to somone else in need when you are done. It will start and idle the car. I don't know about actually driving it around.

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Getz thanks for the generosity. I know the owner of a local pick a part with lots of z's. So if need be I can just grab one and try it out. My ecu is an auto ecu but from what I've read there is no difference. Well it looks like my ecu is not getting turned on since my green light never comes on. Where does the ecu get a 12+ switched from. I thought it came from the #2 plug solid yellow. But moby says thats only for the start signal. So how does the ecu know the ignition is on. I do not think I have that hooked up so that should be my problem. Thanks.

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I Have The Same Car And Motor You Do And Just Installed It A Couple Of Months Ago. Had The Same Problem. There Are Two Yellow And White Wires In The Plug That Goes To The Coil Igniter. I Had The Wrong One And Had No Spark. I Rechecked The Wireing Diagrams And Switched To The Other Wire. It Cranked On The Fiest Try. I Tapped Into The Wire On My Start Button ; Yes A Button Like On The Honda 2000, For Mt Start Signal. And For My Igntion Run Wire I Tapped Into The Black And White Comming Out Of The Ignition Switch. Good Luck.

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Update!!! Ok I have found out my ecu light is not turning on. So its either not getting power (unlikely) or its not getting a 12volt switch telling it to turn on (likely). I have narrowed it down to three locations. The first location is the #2 plug. I have the yellow wire hooked to starter solenoid. The yellow w/ white stripe on the power transistor. And the black and green wire grounded. The other wires are left stock. The other area it might be is the plug next to the #2 plug. It is a white connector with 5 wires attached to it and non of them are going anywhere. My third area my problem might be is over by the battery. I have the efi relay hooked up and then the brown and green wire hooked to the battery. Then there are 5 wires loose. I believe these wires went to the fuel relay. I am using the stock 260z body wiring harness to controll the starter, fuel pump, alt, and etc.... Any help is greatly appreciated. Thanks

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From reading the first post I knew right off your ECU isn't turned on. The black/white wire by the "green" relay is the "on" switch for the ECU. Hook that up to an ignition source and you should be good. Just don't hook it up to the same wire as the coil.. or it won't shut off, that was my problem :twak:

 

Oh yeah and the Blue/Red wire by the black/white wire is the fuel pump relay on signal.

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LOL thanks metro. I just fixed the problem and was coming back to let everyone know what was wrong.:twisted: It was so simple the relay wasn't getting a 12 switch telling to it to turn on. Oh well I guess its better that I figured it out instead of someone telling me. Although the later would have been quicker and easier.:twak: Well now all i need to do is install my o2 sensor, fuel pump, and hook up fuel lines to my fuel cell and it should start. Nay it will start:rockon: Thanks again for all your help.

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