Coil not getting power

Roastin944 · 04-21-2003, 06:45 AM

What would cause a coil to not be getting and juice or power on a 83 944. Thanks

carsontc · 04-21-2003, 10:36 AM

power usally comes from key switch...you wouldn't be the first one to have it go bad...

you got an alarm?

1.2gees · 1.2gees's Garage

Do the injectors pulse?
Ahmet

Roastin944 · 04-21-2003, 10:44 AM

actually im not sure, i dont own the car, but am thinking about getting it. That is the only thing wrong with it is it wont start, he said the coil seems like it isnt getting power. Is there something you can do to find out what is bad so you dnt have to just start replacing things till you find out what it is? Thanks

John

1.2gees · 1.2gees's Garage

Well, the idea is you diagnose and identify the thing that doesn't work and replace only the item(s) that need to be replaced.

If the injectors also don't pulse it could mean a fried DME, crank position/speed sensor, etc. If it's just the coil it could be a # of other things, likely wiring. I believe a DME relay can cause the coil to go powerless, connections at the AFM (or a broken AFM) are possibilities also.
Ahmet

carsontc · 04-21-2003, 11:39 AM

I've 'hot-wired' +12volts to the small black lead on the coil and car started...(bypass key)...had to pull the 'hot-wire' off to stop it.

yeah, I know what your thinking...GTA (grand theft auto)...NOT.!

todwic · todwic's Garage

I've done the same as Tom. Grab your voltmeter, it's a simple matter to do a quick troubleshoot and see if you're getting voltage to coil, or if it's not getting ign. pulse.

carsontc · 04-21-2003, 12:48 PM

if you know for a fact the engine is good (good belts, compression, internals...etc) and the seller is known to be trust worthy, you know this forum will talk you through getting that car started again. dunno the asking price but you know these cars are old and need a lot of TLC and sometimes that gets expensive...so of course, you need to know the maintenance history as well.

88_944 · 88_944's Garage

What I would do is look at some of PelicanParts Electrical Diagrams and see where you can start back tracking the problem.

Go here.
http://www.pelicanparts.com/944/electrical/944_electrical_diagrams.htm

Edit: Looks like DME my friend.

Here's some of the coil ones. I would trace back the positive side of the power to the coil.

carsontc · 04-21-2003, 05:36 PM

too soon to tell. I hear lots of DME units and coils get replaced needlessly. like Ahmet says "replace only the item(s) that need to be replaced"

Todwic & I have just experienced weird reference sensor problems that I'll bet are more common to 'no spark' troubles then coils or DME units. time will tell though.

carsontc · 04-21-2003, 05:46 PM

btw...both the coil AND the DME relay (& other stuff) are powered from the ignition key 'on' switch.

todwic · todwic's Garage

Quote:

Originally posted by carsontc
too soon to tell. I hear lots of DME units and coils get replaced needlessly. like Ahmet says "replace only the item(s) that need to be replaced"

Todwic & I have just experienced weird reference sensor problems that I'll bet are more common to 'no spark' troubles then coils or DME units. time will tell though.

both statements are true true true