Got it in car, having trouble

[accordaffair]

Hey all, new member, first post.

I got my mpguino assembled and running, and today I got it wired into the car, but it's not working. It stays at zero like it would with no input.

I'm wondering if the resistance inline is too high.

With the key on, and engine off (KOEO) the vss sends .17v
KOEO injector 1 sends 11.32 volts

With the Key on engine running (KOER) the injector fluctuates between 13.5 and 13.65 volts
The VSS still sends .17 because its not moving

Now where those leads meet the circuit board the readings are lower of course

KOEO vss provides 0.0 volts, sometimes barely giving 0.1
KOEO inj provides .56 v

KOER vss gives .01 volts and inj gives .56-.57v

This is installed in a 93 honda accord ex, I did some rudimentary math and changed my code to

vss - 4104
966488100 microsec/gallon
tanksize 17000

using v0.63

The numbers I will change when I get some readings but I can't get that far yet. Any suggestions?

[dcb]

take a look at the "Instant Raw Data screen" whilst toodling around, uS should be proportional to injector duty cycle, IC should be porportional to RPM, and VC should be porportional to the vehicle speed.

If none of those show anything then describe where you tapped the injector and the vss? What color is the vss wire and what color is the injector wire?

[accordaffair]

all screens show nothing but zeroes, as if I never hooked them up

vss I tapped into pin b10 by the ecu, injector 1 I used a brown wire with I think red dots, pin A1. I plotted these pins using my helms repair manual. I'm almost 100% certain I'm using the correct pins, BUT I should be using the positive leads for both of these, correct?

As an aside, the power plug the guino comes with doesn't seem to do squat, I have to wire up to VIN and GROUND, on the board for it to work, does that sound right? I wired both at the same time, just to be sure

I'm using rj45 ports and a length of cat5 to run the signal from the ecu area to the guino

I'm off to work, I'll be back later tonight

[Whoops]

I don't know about the VSS, but on the injector, it runs off of what you might call negative logic. The power to the injector is supplied whenever the fuel relay turns on. The ecu provides a signal which grounds the other side of the injector when it turns the relay on.

[dcb]

For VSS, if you can find a picture of the ECU plug online I might be able to point out the speed signal, my cryptic docs indicate it should be Pin 8 on a 24 pin connector, maybe yellow/white, or orange, or yellow/blue?

For the injector, you unplug an injector and turn on the ignition (not the engine) and use the injector wire that DOESN'T have 12 volts on it.

[accordaffair]

Originally Posted by Whoops

I don't know about the VSS, but on the injector, it runs off of what you might call negative logic. The power to the injector is supplied whenever the fuel relay turns on. The ecu provides a signal which grounds the other side of the injector when it turns the relay on.

So should I be running a ground? what completes the circuit, ground to ground? I'm not proficient in electronics, I have an amateur knowledge.

Originally Posted by dcb

For VSS, if you can find a picture of the ECU plug online I might be able to point out the speed signal, my cryptic docs indicate it should be Pin 8 on a 24 pin connector, maybe yellow/white, or orange, or yellow/blue?

For the injector, you unplug an injector and turn on the ignition (not the engine) and use the injector wire that DOESN'T have 12 volts on it.

VSS, it was a bright orange wire

injector, to test my manual says use a1 for injector 1 and a23 for ground. But using a23 would not give off a signal just a ground? Am I wrong?

It does say to measure for battery voltage so it is the one putting out "12v"

I do use an injector resistor in this car if that makes a difference

This pic is for an integra but it should be exactly the same as the OBD1 accords



can't find a pinout, but I'll keep looking

*EDIT*found one
http://www.superhonda.com/forum/f55/...inouts-217405/

[accordaffair]

Don't know if this helps

[dcb]

Are you using B10 for the vss?

http://www.innovatemotorsports.com/r...nda_Accord.php

[accordaffair]

yup

[dcb]

Can you rig up some alligator clips or test leads and and watch the voltage on b10 as the car rolls slowly?

P.S. the ECU will ground out the other side of the injector, you want to be tapped into the injector line that leads to the ECU, not the one that leads to the resistor.