Help No Power Going To Coil

[bimmer206]

I apologize for the bickering.

OP in your original post you stated that you have no power going TO your coil is this correct? I.e. the the small green wire does not have ~12v with the key in the run position?

Can you please confirm yes or no.

No power when the key it turned to run or while cranking is going to the coil (green wire).

[bimmer206]

I apologize for the bickering.

OP in your original post you stated that you have no power going TO your coil is this correct? I.e. the the small green wire does not have ~12v with the key in the run position?

Can you please confirm yes or no.

No power when the key it turned to run or while cranking is going to the coil (green wire). I can't find what the ohms should be for the reference sender in wedophones manual.

[Adrian_Visser]

I feel kind of like a broken record seeing as I have said this in every post I have made but: THE REFERENCE SENDER DOES NOT EFFECT POWER GOING TO THE COIL. How many times do I have to say it?

The reference sensor is what the DME uses to decide when to fire the coil, the coil should always have power on the positive terminal (green wire) coming from the ignition switch in the start and run positions. If you do not have power to the coil I would suspect either a broken wire on the switch or a broken contact in the ignition switch itself. Of course it could also be a break in the wire somewhere in the wiring loom as well.

Page 35 of the etm http://www.wedophones.com/Manuals/BM...g%20Manual.pdf

[Cabriolet]

Adrain is right, i thought u had power on the green wire.
other things to check:
do you do not hear the fuel pumps come on, could be fuse-able link in trunk next to battery, or main relay. could be a cheaper fix than some of the other options.

[bimmer206]

My car wont start, it turns over but doesn't start. I checked for spark got nothing so i then checked for power after the coil and again nothing, so i then used a multimeter to see if power was even going to the coil and there's none.

• Which fuses and relays are specific to the ignition system?
• Is there a fuse able link that i should check?
• What are your other thoughts to why the coil is not getting power?

It says in the first post that there is no power going to the coil. The green wire is dead. Now your saying it could be the ignition switch? If i were to bridge power to the coil could i rule out whether it's the ignition coil or not? Like i said I've checked the fusible link in the trunk it's good, i'm not sure how to check the main relay however. I'll search.

[b*saint]

Jump power to the primary side of the coil. See if it starts.

As someone said before. Its either the a bad ignition switch or bad supply.

[bimmer206]

I am getting power to both the positive and negative side of the coil. My friend who rebuilds classic muscle cars checked power going to the coil and I guess he made a mistake however I'm getting less than 12 volts about 10.5. There is still no spark after the coil or at the plugs.

[b*saint]

bad coil OR there is a shunt or something somewhere that the ecu controls to control timing??? Thats what it looks like in the schematic.

[DaveSmed]

lol internet car diagnosis....


Seriously.... Depending on if power is or is not going to the coil makes a hell of a difference. If that particular circuit in the ignition switch was bad, half of the shit in the car wouldn't work.

So, assuming power going to the coil.... Rest a screwdriver on a fuel injector and listen for clicking while cranking. If its clicking, your coil likely has problems.

If its not clicking, pull a connector off. Check the red/white wire for +12v while cranking. If you don't have it, your main relay likely isn't functioning.

If you have +12v, ohm out the timing sensors. If they ohm out ok, that is no guarantee they are good, but start investigating into the whereabouts of your TDC pin. That bad spot on the flywheel could also make your car run like crap if its bad enough.

There. That's what commonly results in a dead eta. Go fix your car and report back.

[DaveSmed]

I feel kind of like a broken record seeing as I have said this in every post I have made but: THE REFERENCE SENDER DOES NOT EFFECT POWER GOING TO THE COIL. How many times do I have to say it?

The reference sensor is what the DME uses to decide when to fire the coil, the coil should always have power on the positive terminal (green wire) coming from the ignition switch in the start and run positions. If you do not have power to the coil I would suspect either a broken wire on the switch or a broken contact in the ignition switch itself. Of course it could also be a break in the wire somewhere in the wiring loom as well.

Page 35 of the etm http://www.wedophones.com/Manuals/BM...g%20Manual.pdf

BTW, listen to this guy, his advice was on point with the information he was given.

[bimmer206]

I replaced the coil with a brand new one and the car still didn't start so I took that coil back. Still stuck in the same spot. Okay just saw the new posts sorry I'm using my phone. Tomorrow ill check the reference sensors but I'm confused why the injectors could be the problem. There is power to the coil but no spark after the coil or at the plugs.

[bimmer206]

I replaced the coil with a brand new one and the car still didn't start so I took that coil back. Still stuck in the same spot.

[DaveSmed]

The injectors are another component controlled by timing events as commanded by the DME. If they work, then the DME is receiving and processing the timing signals. IE the input to the computer is working and the computer is processing correctly. Failure lies in between the output stage of the DME and wherever your checking for spark.

The power for the injectors is shared with the power for the DME through the main relay. Checking the injectors is far from a perfect solution here as the relay has two legs that must be energized for the car to start, but it is verifying that at the very least half of the relay works, that its energizing when appropriate and it is sending power out of one leg. No power to the DME, no timing event obviously..

Which brings us to the timing sensors, as we went from the DME's output, power, and now the input. The DME uses the teeth on the flywheel ring gear to get RPM, and the single TDC pin so it knows when to begin the timing events, and continue them at x flywheel teeth intervals, until the TDC pin comes around again. The sensors are the two wire VR style AC generating sensors similar in operation to ABS sensors. The third pin is the shield.

See how those three checks narrow stuff down pretty quick? Keep in mind this is very simplified, I concentrated only on the most common faults that result in no starts w/o spark on etas.

[StereoInstaller1]

The DME tells the injectors when to squirt AND the spark plugs when to spark based on 2 things: power to the DME and signal from those 2 sensors in your bellhousing.

DME power comes from the main relay. The main ALSO has a second circuit that powers the fuel pumps...but to make it really confusing, the DME ALSO turns on the main relay.

Here is how to bypass the main relay: make a 3 pronged jumper using 3) 1/4" male spade lugs and a couple of feet of wire. Jumper the 3 big red wires on the main relay: that is the one at the front of the 3 relays on your left front fender.

Also, make sure that pin 30 has power going to it.

IF you do this really simple test and your car runs, it is likely the main relay. Your car will not shut off with that jumper in place BTW, you must pull it before you shut it down.

[StereoInstaller1]

For Dave: Main is SPST, but 2 N.O. contacts.

Look at 1362-2 on the ETM. That is the ETA spec, but all are the same.