Wiring problems. Short somewhere.

[oldude]

This is way too long.

Bottom line, why would I get sudden drop in power. Engine just quits.

Does Fuel pump control do this? Can something else do this.

This is 2nd, actually 3rd if you count the original disty, that I have gone through.

Thanks

 

 

83 EA81 2WD StaWag GL. Nippon Denso disty.

Started out as a blown disty. There is a thread I started before and got some help.

Now I'm through my 2nd disty after having already blown up one. I think I still have one that works, but here is what I've found so far as to the cause of it blowing in the first place or now coincedence is driving me crazy. Anyway, testing for voltage at coil and such, and after finding out that the Subaru dealer/mechanics had hooked up my auto choke wrong which was shorting out and causing my rad fan to come on. I ramble, but bear with me. It's while I was moving wires around to get my tester in position to check for coil voltage, the fan went on and off and so... that led me to start checking out what else they might have done and found another test wire they had hooked up but never told me nor removed it brfore I picked it up. This gaused some wires to melt, but I think I localized them and that prob should be OK.

Phew!!

Back to testing for voltage.

Wait.

First, when I first hooked up the 2nd good disty, I was psyched. It started right up and seemed to need just a little timing and I was good to go. Let it warm up, and then after 15-20+ minutes....it quit. All of a sudden. No sputter, coughing,....just poof....quit. Jiggled wires, mades sure I had hooked up everything right. Felt ignitor in disty, as last time I had the problem, with a new disty, I had noticed it extremely hot. Well this time it wasn't. But I then tried to start again and it did, but this time it ran for just 15-20 seconds. Like before. Sudden. Even had my eye on tach and watched it just frop off, too. So I started to check things again. Thought Fuel pump, or control. Found power sometimes, but intermittent.Ended up with now, with just the positive cable hooked up to battery, if I pust voltmeter lead+ to Engine ground and other- to neg side of battery, I get 12+- volts. Neg cable is NOT hooked up. So no good ground, yes??

Went to fusible link box, under hood, next to battery, with pos. wire straight from battery, spltting at link to 3 wires, W BW and WB. So playing with those, I get same pos. volt reading at neg connections like I said above, with 2 of those wires. WB seems to go to fuse box and manual says it's for clock. Manual seems wrong, because clock still lights up even with fuse pulled. But regardless of what it goes to.....If I check my neg volt reading thingy I get pos reading with fuse in. No reading with fuse out. So that seems to be one prob.

Bear with me if you made it this far.

Volt test with W wire seems to be connected to ignition switch. With key off, no pos reading on eng ground/neg bat post thingy like above. With key on, 2 places/click before start, I get that pos. volt reading again. So there seems problem No. 2

Any quick/easy suggestions? If I have to I guess I could trace both wires completely, but I hoping for something easier. I thought of trying to just how-wire at connection on steering wheel for ignition, starting. That might tell me if the key/ignition switch is at fault?

The other possible short....I'm clueless, other than complete trace. I suppose I could just disconnect altogether, eith at fusible link box or by removing the fuse. But it probably runs something vital so, who knows.

I'm not that good with elec. stuff. Little patience, and littler knowledge. Have little handheld tester, but really only know very basics. Like testing for voltage. I wish I knew more about continuity things...Isn't that a means of finding shorts other than visibly finding bare wire.

Questions are: How/what should I be looking for with ignition switch short? Should I consider replacing switch? Or just hotwire. That's assuming short is in switch, not somewhere under dash, through firewall, etc, to fusible link

Question 2

Does WB (white w/black stripe) really go to clock at fuse box as manuals suggest or what?? How do I test. Just pull fuse and hopr for the best.

I'm open to any and all advice.

If you've read this, thanks for your time. Of you answer or point me in right direction, thanks even more. I've downloaded several wiring diagrams. All a bit different, but similar.

Thanks again

[cowboystrait]

its ur coil or ur coil pack coil= round + on left - on ur right coil pack= is sqare box little wires every where:) thats my therory

[Cougar]

Wow, that was some hard reading.

 

You stated that you removed the battery ground lead. You then measured voltages and stated you had a bad ground. I don't know what you were trying to prove by doing this. By doing that, there is no ground. The car systems will be floating and you will get all kinds of strange readings. You need to have the negative side of the battery tied to the vehicle ground system to make valid voltage measuements.

 

The ignition coil is in between the supply power and the yellow wire to the disty. Is the yellow wire tied to minus side of the coil as it should be? My info shows the disty is also tied to a knock control unit. If that is correct then maybe there is a problem with that.

 

As far as measuring continuity it is checking for resistance between the meter probes. If the reading is zero ohms when taking a reading then you have a short between the probes however things are tied together.

[oldude]

Sorry about the hard reading.

 

I didn't start out trying to get these diff. volt readings. Pure coincidence.

I just didn't understand why the engine would stop so all of a sudden like. Or why it seemed as if I was blowing up distys. If not a short, what could cause the sudden stoppage. I would think if it was a fuel problem, the stoppage would be not so sudden.

It's like someone just pulled the plug.

[Cougar]

I assume this is a carburated model you have, is that right?

 

Let's see what is working. Do you have spark getting to the plugs or is there still a problem with the disty? Is the ECU flashing any codes?

[rallyruss]

argh! that hurt my brain.

 

ok lest make this a bit less complicated. I am not really shure what or how you were testing things from your description.

 

first off it seems you can duplicate the problem easily. thats good. you need to verify where the problem is before going too deep.

 

does it have spark(pull off the coil wire and see if it will spark to ground with a decent blue, 1/2" or greater arc.

if its yellow or cannot jump far its a weak spark.

 

if you have spark do you have fuel? pull off the fuel line and run it into a container. crank the motor over(dont forget to hook the coil wire back up) you shold get a decent amount of flow out of the line. dribbles dont count.

 

If there was no spark then you first need to verify does coil recieve power. use a test light and check at the pos.+ post. if you have power then check the neg- side of the coil. when the engine is cranking you should see the test light flicker. that means the power is making it thru the coil and the distributor is "switching" or pulling the coil to ground and releasing to make spark.

 

if you do these simple tests then you can isolate where to look for your problem.

 

oh and Cougars are good with electrical you should listen to them.

 

you may want to look up voltage drop testing also as thats what I think you were attempting to do with some of your tests. when done properly it is very helpfull.

 

good luck and keep it simple.

[oldude]

Hi. First of all, thanks for the help. This is making me cuckoo.

 

It is carburated.

I do get spark. I do get fuel......At times. By this I mean, it seems as if sometimes I am not getting fuel. But I've hotwired the fuel pump, disconnected lead going to fuel pump control unit and hotwired.

As for spark. I did get spark. Had my son crank engine with plug wire off No. 1 and used extra spark plug. Got spark. But to be honest, when it died, I haven't rechecked to see if I'm still getting spark. Will do tomorrow.

I do get 12v at disty. Haven't tested while cranking for pulse spark. Will do tomorrow, also.

What can shut engine down? My understanding is there is a safety feature that shuts down fuel?? Yes?? Does fuel pump control do this?

Is there anything else that would shut down.....stop spark from getting to plugs.

The suddeness of it quiting throws me. If fuel was shut off, I'd expect not such a sudden stoppage.

Oh. ECU flashes 22. Same as before when I first switched to new disty. And I've been told to clear any codes I was to disconnect battery for at least 10 minutes. Done that, for even longer than 10 min. but code still flashes.

More testing as y'all suggest tomorrow and I'll re[prt back

Thanks again

[Cougar]

If the ECU doesn't see the proper pluses from the disty it will turn the pump off. Usually the pump is grounded through the ECU.

[rallyruss]

If the ECU doesn't see the proper pluses from the disty it will turn the pump off. Usually the pump is grounded through the ECU.

 

this is true and very well may be related to your problem. somthing to think about.

some subes had a fuel pump relay others did not. The ones without rely on the transistor in the ECM to do the switching. I have had problems with this before on my old subes.

report back with what you find.

[oldude]

Hi. Been raining, but managed to try a quick test.

 

Now no spark at plug.

I had changed coil, ECU, fuel pump control, but put all back as I thought I'd start all over again.

First quit w a Code 22. That's when I changed disty and it worked for 3 days, then kaput.

Now I think I'll try changing things again, one at a time.

Coil first?

[Cougar]

Instead of guessing at what is bad I would do some trouble shooting with a voltmeter to see where voltage is getting to or not. If you have voltage to both sides of the coil with the ignition ON, it is probably ok. You then need to see if firing pulses are on the negative side of the coil. By placing a test light on the minus side of the coil and ground the light should pulse with the firing pulses when you crank the engine. If you just have a steady light, which I suspect will be the case, then the disty circuit needs to be checked along with the ignitor.