Im very interested in building a electrical system from scratch for my Street/Strip car

I plan do the following

1. Ditch the stock Gauge cluster and build a new one from Defi gauges.
Fuel Level, Fuel Pressure, Oil Pressure, Tach, Speedo, Water Temp,

2. Wire up Turn signals from scratch.

3. Fuel Pump to a Board.

4. Run ALL wires from ECU straight to the Motor.

Here is a Pick of the Relay Board that im going to use.. Maybe 2 because of my HID setup and Possible LED tailight setup









Here is what i need to know

Are the Injector wires at 12v as soon as the key is on? Do these wires get power from the ECU or another source?

Where can i get the OEM ECU pins from? does anyone have the Part # for the ones to be used for a OBDI p28 ecu?

The Ignition is still going to use a Key. How would i wire in the igntion. I know there is like 4-5 wires coming to it.

 

usually on a fuel injected car the ecu squirts a little bit of fuel when the key is on to help the car start

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ILLICON5000 &raquo;</TD></TR><TR><TD CLASS="quote">usually on a fuel injected car the ecu squirts a little bit of fuel when the key is on to help the car start</TD></TR></TABLE>

well i planned to have the ECU, Fuel Pump, Fan, Interior Light all on a switch board.

I would turn the ECU on First then the fuel pump and then start the car.

 

The injectors get their 12+ source from the main relay, I believe. The computer just uses the ground circuits of the injectors to fire them.

 

Main Relay is going to Be Gone. Not using one. Everything is going to be running off the relay boards

 

where did you get that board at and how much $$

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMlyfestyle &raquo;</TD></TR><TR><TD CLASS="quote">Main Relay is going to Be Gone. Not using one. Everything is going to be running off the relay boards</TD></TR></TABLE>

If you remove the main relay then the fuel system won't prime when you turn the key unless you manually turn on the fuel pump to do so. ( Sounds like you will). However, the main relay is there for safety. In the event of an accident, rollover, etc whatever can cause the engine to stall the computer signals the main relay to cease pumping fuel. Otherwise in an accident if the fuel line gets severed it'll be pumping a potential flame thrower all over the place.

You should reconsider using the stock main relay, or build an adequate circuit to take over the main relay's responsibilities.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18ccivics &raquo;</TD></TR><TR><TD CLASS="quote">where did you get that board at and how much $$</TD></TR></TABLE>

I have a Friend that makes them. ive already gotten several PM's about them. $125 plus shipping for them

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jeremydde &raquo;</TD></TR><TR><TD CLASS="quote">

If you remove the main relay then the fuel system won't prime when you turn the key unless you manually turn on the fuel pump to do so. ( Sounds like you will). However, the main relay is there for safety. In the event of an accident, rollover, etc whatever can cause the engine to stall the computer signals the main relay to cease pumping fuel. Otherwise in an accident if the fuel line gets severed it'll be pumping a potential flame thrower all over the place.

You should reconsider using the stock main relay, or build an adequate circuit to take over the main relay's responsibilities.</TD></TR></TABLE>

Im trying to locate some microswitches (similar used for SRS system) that will Kill Everything Apon a Accident. That Way If the vehicle is not damaged all i need to do is install a new switch in the place and the car will be ready to rock n roll again.

 

All I have to say is

Goodluck.

Before you start this do a bit more research on how everything works before you get yourself into a hole..

Injectors have constant 12V, the ECU has a wire that goes to each injector to ground them (fire)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HamiltonRex &raquo;</TD></TR><TR><TD CLASS="quote">All I have to say is

Goodluck.

Before you start this do a bit more research on how everything works before you get yourself into a hole..

Injectors have constant 12V, the ECU has a wire that goes to each injector to ground them (fire)</TD></TR></TABLE>

Ive done quite a bit of research on it but i just wated to clarify something.. I got a complete list on pinouts on everythings.. All of the sensors are going to be netting, shrink wrapped on the ends and picked up some shielding to protect the signal of all the sensors that way i dont pick up any outside noise on the hondata.

 

goodluck man. post pics of your progress. i would like to see and learn from this....

 

the inertia switch on my friends 1990 f150 is just like a circuit breaker. it shut his fuel pump off on him when his clutch line blew thinking there was an accident. all he had to do to get it working again was push a button. just curious, why wouldn't you want to use an oem main relay? its just more work to make your own.

 

Sounds like a fun and challenging project.

Are you planning on wiring in anything that the Honda wiring doesn't currently have?

 

a mercury switch might work if all you want it to do is sense if the car is upside down...

 

I think im gonna use some SRS switches just incase of impacts

 

injectors do not use 12 volts. they would fry them. im not sure on honda's but typically most cars use around 5 volts and a transistor for ground to fire them. damn i wish i could remember right now.

soon as i remember i will be coming back

would also really depend on injector impedence.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by postman &raquo;</TD></TR><TR><TD CLASS="quote">injectors do not use 12 volts. they would fry them. .</TD></TR></TABLE>

Yes they do..

Well, some do, some dont.

If a resistor box is used its 4.5V if there is no resistor box it is 12V

 

so you restated basiclly what i said, thank you

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMlyfestyle &raquo;</TD></TR><TR><TD CLASS="quote">

1.) Are the Injector wires at 12v as soon as the key is on? Do these wires get power from the ECU or another source?

2.) Where can i get the OEM ECU pins from? does anyone have the Part # for the ones to be used for a OBDI p28 ecu?

3.) The Ignition is still going to use a Key. How would i wire in the igntion. I know there is like 4-5 wires coming to it.</TD></TR></TABLE>

1.) Yes, Stock at least. If you are going to run saturated injectors (Like stock OBD1) they will get 12v when you put the key in the on position. If you want to run “peak and hold” injectors you will need a resistor box inbetween your injectors and the 12v supply.


2.) Honda will not sell you pins for the ECU damn them! You can however purchase a terminal/plug kit from AEM that has brand new ECU plug housings and new un-crimped ECU pins (Both sizes). I believe its like $30-$50, I can’t remember.

3.) You are going to need to run 12v to your ign switch and connect it to the common terminal (see the service manual for your car). Then from the terminal on your ign switch that gives you 12v when you turn the key on and stays on while starting, to a main relay (I know you don’t want one, but you should use one). Place the main relay between your battery and your nifty relay board you’ve got there.

Put a fuse between the power side of your main relay and your ECU (ECU doesn’t need it own relay)

Your ECU has an output for your fuel pump that you would want to connect to your relay board to activate your fuel pump. This serves more than one purpose….
The ECU will prime your fuel pump when you turn your car on. It will then send a constant signal to keep your fuel pump running when your engine is running. Finally it will kill your fuel pump should your engine dies or you shut it down.



Modified by TrueNorthStar at 7:20 AM 6/15/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMlyfestyle &raquo;</TD></TR><TR><TD CLASS="quote">

I have a Friend that makes them. ive already gotten several PM's about them. $125 plus shipping for them
</TD></TR></TABLE>

damn! thats pricey. I could make one for less

I still like it though

 

i have to bump this up from the dead... did this project ever get completed?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by postman &raquo;</TD></TR><TR><TD CLASS="quote">so you restated basiclly what i said, thank you</TD></TR></TABLE>

A part of it yes. But, you said injectors do NOT use 12v.

 

saturated injectors are 12v right? then peak & hold are less.

 

Also, the injectors will have a solid 5 volts on them. They are "activated" by a ground pulse sent from the ECU.

 

My Mistake, the Inejctors will have 12 volts on them.