Wiring Detectives Needed

[werx]

I'm trying to track down a short in the coil pack circuit. So does anyone know where the Coil pack connector's blue wire with red stripe connect to?

 

[whe3ls]

it can go to either the ecu, mpi, or to the power transistor.

 

[werx]

I traced the blue wire with with stripe to the Power Transistor. I haven't checked the MPI relay. Thanks for the lead.

 

[Scoobystyl]

Whats the problem your having? no power to the coil pack?

 

[werx]

Not getting spark to two of the spark plugs. Using a test light, I tracked down the proble to the coil controlled by the blue w/red stripe wire. It lights up but it doesn't blink which leads me to beleive there is a short in the circuit....somewhere.

 

[Lou98GSX]

i think that there is power all the time and the ecu controls the ground side

 

[werx]

So are you saying that there is a bad ground somewhere?...or the ECU could be bad?

 

[Lou98GSX]

usually the power transistor causes this problem

 

[Scoobystyl]

Check to see if you have power to the coils, the cas and maf. If not check for power at power transistor if none there check for power at mpi relay. its wired in fairly simple. Let me know what you read at each of those points and ill help as much as i can.
Did you recently rewire anything or replace anything?

 

[DDualan]

i just had this same problem, it was my power transistor good place to start

 

[Scoobystyl]

i just had this same problem, it was my power transistor good place to start

Before replacing things its good to test the wiring cause its free
You can also test your power transistor

 

[werx]

okay we'll check the power transistor. Thanks for the leads. I'll let you know what I find out.

 

[Spector5]

Don't use a 12v test light, get your self a dmm(digital multi meter), you can screw up your compenents with test light, hint hint:12v test light on a 5v circuit on the PCM side.

Do you have power to the coil? As Dduluan said the circuit is controlled on the ground side, so you should have a 12v source to the coil, but 5v's from the PCM controls the switch to turn on and off the coil itself

 

[werx]

Okay here's an update on my electrical problem. I tested the power transistor with my multimeter and a 1.5V AA battery for continuity. The pins controlling coils 1/4 had a higher ampherage than the pins controlling coils 2/4 so I figured that was telling me that the power transistor is bad. So I ordered another pt and hope to have it connected tomorrow. Again I'll keep you guys informed. Thanks for all the help.

Okay picked up the power transistor tonight...put it in and....I'm still having the same problem. So the only thing I'm thinking is left in the circuit is the ECU...!