Starter Wiring

[metalix1021]

So, I had to replace my starter in my '91 325. I took the intake manifold off and everything else the Bentley suggested.

The Bentley, however, does not give a good picture/instructions for the 4th wire that my '91 has. It's solid black and I thought it went on the smallest stud on the starter. The Alternator and battery wires go on the positive, the ground strap on the other large stud and the black and yellow wire in the stud on the bottom if the starter is oriented the way it is in the car.

The problem I am having is that I have no spark. The starter cranks no problem, just no spark. No spark at the coil and no power to the coil.

It had spark before I took everything apart to replace the starter.

I did some searching and my crank position/cylinder ID cables are plugged in correctly. I unplugged and replugged everything in just to make sure it wasn't a loose connection.

Ideas? Again, I am not sure where the small black wire goes and that could be the problem.

Thanks in advance.

[Rocla]

I took the intake manifold off and everything else the Bentley suggested.

Seriously? Burn that manual please.

The problem most likely isn't in starte wiring, you've propably missed some wire underneath the manifold.

[metalix1021]

Seriously? Burn that manual please.

The problem most likely isn't in starte wiring, you've propably missed some wire underneath the manifold.

well....it made it a lot easier to get to the starter, I also wanted to clean it up, put new gaskets in, etc....

All the wiring is hooked up. zero hanging wires.

[metalix1021]

OK, so the starter is/was wired correctly and I can also rule out the fusible link.

What to test next?

[Jean]

ignition coil, ecu, crank sensor.

[metalix1021]

there is no power to the ignition coil, but just for shits and giggles i swapped in another and same problem

ECU and crank sensor are possible

Is there a way to check the ecu without just swapping in a new one and seeing if it works?

[Jean]

Well, you would have to read through the ETM and know how to check the ECU at it's pins... it would be simpler and faster to just swap a good one in.

If it all worked fine before, I would triple check all the wiring and connections.....

[metalix1021]

Well, you would have to read through the ETM and know how to check the ECU at it's pins... it would be simpler and faster to just swap a good one in.

If it all worked fine before, I would triple check all the wiring and connections.....

Yeah, never hurts to check again, thanks.

[Rocla]

If there is no power to coil then the problem is not in sensors.

[metalix1021]

If there is no power to coil then the problem is not in sensors.

Ok, so my choices are what? the DME and anything else?

[Goya20]

if my idea is right that wire has to connect to the engine block itself cuz that leads to ground and if the starter doesnt spark it is that. parallel with the starter on the block there should be a bolt or a hole which needs a bolt for the starter.

[metalix1021]

if my idea is right that wire has to connect to the engine block itself cuz that leads to ground and if the starter doesnt spark it is that. parallel with the starter on the block there should be a bolt or a hole which needs a bolt for the starter.

The starter cranks well an I figured out the wiring is correct in that spot.

So, either the DME is not sending a signal to the ignition system to fire or there is a wire broken somewhere in between. Does this make sense?

[Rocla]

The starter cranks well an I figured out the wiring is correct in that spot.

So, either the DME is not sending a signal to the ignition system to fire or there is a wire broken somewhere in between. Does this make sense?

Yes, it makes sense, but...

The +12v to coil comes from ignitoin lock and DME sends the grounding signal to coil, so if there is no +12v to coil(green wire) while ignition is on the problem is not in ecu.

Does the ICV make sound when ignition is switched on, or does the fuel go on for a second when you put ignition on?

[metalix1021]

Yes, it makes sense, but...

The +12v to coil comes from ignitoin lock and DME sends the grounding signal to coil, so if there is no +12v to coil(green wire) while ignition is on the problem is not in ecu.

Does the ICV make sound when ignition is switched on, or does the fuel go on for a second when you put ignition on?

ICV does buzz when ignition is switched on. I couldn't feel/hear the fuel pump when ignition was switched on, but I will make a more definitive check tonight.

OK, makes sense about the coil stuff.

[jlevie]

The fuel pump is controlled by the DME and only runs when the DME sees timing data from a rotating engine. The pump doesn't run just because the ignition is switched on.