Any way of testing the transister unit next to coil on the turbo cars? I have no spark and injector fire and thinking it may be it? It's a 82 Turbo Model thanks



Edited 2 time(s). Last edit was august 18, 12:30pm.

just check the output wire from the transistor unit for power with a voltmeter while turning over the car

You should be able to apply 5 volts to the yellow/white wire quickly and see te coil spark. DONT hold the wire on the terminal, or it will get hot and short.
The other thing you can do is use a scope and probe that wire and look for about a 4-10 millisecond square wave @ idle.
Hope that helps

I do have power from Transister unit but checked and put a noid light on 1 fuel injector and no blinking there and no spark any ideas?

The injector doesn't have anything to do with the ignition, so it appears the ignition is not the problem - no the normal situation.

If I were you I would get some contact cleaner and spray it on the injector connections and at the main harness where it plugs into the ECU. Plug and re-plug it in a few times to make sure you are getting a good connection.



Edited 1 time(s). Last edit was august 18, 02:43pm.

Make sure your coil bracket is tightened down well.If it's loose,you won't get any spark.Just my 2 cents.

Doesn't ignition and injectors fire off of signal from pickup coil in dist.?

The power transistor does need to be grounded well. The bracket holding the transistor is the ground for the part.
The injectors should have 12 volts on one of the wires with the key on, if not look at the EFI relay under the black square cover next to the battery. The relay is GREEN. Check that for a 12 volt feed and that it clicks when the key is turned on.
You should have 12 volts on the black/white wire on the power transistor connector when you turn the key on also. Check the fuse link box to make sure the GREEN link is good. Check to see that there is 12 volts on that link all of the time, it is directly off the battery.
Yes the injectors are triggered by the distributor, and the other trigger is a 360 pulse trigger every two crank rotations. You should also be able to see these on the scope.
The fuel pump should cycle every time you turn the key on, and then if it doesn't then crank the engine a little shut it off and turn it on again and then the pump should cycle for 5 seconds.
Hope that helps you.
if you dont have anything from these tests, I would start to suspect the ECU being bad. Well except the fuse link test.

You do not 'have power' to the transistor ignitor!

You have power pulses.

Take your meter and crank it down to 1-5 or 1-12 VDC setting. If you have a GOOD meter when you crank it you should see PULSING of the signal on the yellow wire to the ignitor.

If you have that pulsing, the ECU is sending out a signal, and you either have a bad ground on, or bad ignitor transistor.

If you do not (and I think you don't for the reasons you gave on not having an injector pulse---injector will NOT pulse unless a spark signal is read feeding back from the coil for RPM Signal) have the pulse out of the ECU, then you have to probe the wire from the CAS on low voltage for the same kind of pulsed signal back to the ECU. You will need to read the ECCS Wiring Diagram to determine which pin you have that signal into the ECU on, but like Jeff said that one may be easier to probe on an O-Scope...but a fast meter reading 5VDC will show the pulsing.

If you have a CAS signal to the ECU, and no output, then the ECU is shot.

You do not simply probe for power...if you have 12VDC (I mean, what are you checking for when someone generically says 'check for power' anyway?) on that line, you either have a cheap meter or something's fried, or you are probing the power wire to the transistor and not the GATING signal.

True, if you don't have 12VDC to the power input side of the transistor you won't get spark as the coil won't charge up...but you need a GATING signal from the ECU to make it spark.

This has been covered in the past extensively, including the 'scrape test' with little bits of wire so you can simulate a gating pulse (similar to what JeffP said to do) so you can see if the ignitor will gate the coil, if the coil is indeed good, etc etc etc...

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