Still No Spark

[burnt_toast]

Went back out with the LED test light to the injector harness with all 4 connectors unplugged. The YEL/BLK is the 12V constant and that works (Green LED key OFF, red when key ON or START).

the GRN/BLK should be the ground wire. My expectation is the LED will not light up when probed, and would blink from off to green as the pulse signal was given. Am I correct in that? Anyway, when I tested it the LED did not light up at all with key OFF, ON, or START.

At this point I see nothing that would cause the injectors not to pulse and the ICM not to pulse except the ECA. The fusible links are good and (unless I misunderstood the test) the main relay works.

-toast

Yellow/Black should have 12Volts + at all times with the switch in the On/ Start position and will not pulse.
Green/Black is the negative wire going to the ECU and is the one that the ECU turns on and off.

[FestYboy]

when you probe the grn/blk wire, do you still have your test light connected to the battery ground, or did you switch it to the battery power before cranking?

[burnt_toast]

It has a positive and negative lead, so it is connected to both. It lights up the LED red if it's positive and green if it's negative:

http://www.harborfreight.com/compute...obe-98709.html

I assume the circuits are separate though I never actually tried to use it as a conventional test light with only one of it's two leads attached. I've honestly never seen one before until I started this thread; it was just the only LED testlight on the shelf.

-toast

[FestYboy]

ok gotcha! i'm still thinking in terms of standard test light usage.

[tooldude]

Since I had to break off to tend some of my business, I'm going to have to get reoriented with a little rereading. I'm really trying to not make a mistake here. I'll have to make several posts from this point because I'm spending some time with some of them. Until I catch up, I'm not exactly sure what point you're at right now. I'm working from the possibility that the ECA could be bad but I wasn't expecting you might be able to swap it out. First, from post #90, the easiest way to jump around both the fusible link and main relay is at the self-test connector under the hood (in your Haynes manual 6-5). In the schematic (your 2nd picture) you see that connector taps off the Y/BK wire for B+. Just plug into the self-test terminal with the Y/BK wire, with your jumper wire ( to be clear: from battery+, through a 15A inline fuse, with crimp-on terminal end to fit into self-test connector). Assuming good connections, you've powered the entire Y/BK wire (actually there is no good assumption in troubleshooting).[Just don't let it short to any adjacent terminal: connect the terminal before the battery and disconnect in reverse] I know you already found voltage, but it's static voltage in a non-operating circuit; that doesn't guarantee proper amperage through that circuit (as getnpsi also suggests). The relay contacts have yet to be proven good, so this gets around that. Now I'm going back to read up on that post about the ICM wire.

[tooldude]

Back to post #90. So you probed the BL/O SPOUT wire and you get ground under all conditions, green at all times? Was that light blinking when you crank the engine or steady? The SPOUT signal is supposed to trigger a ground for each spark so the light should blink. If it is blinking then check if you have spark now. If it's not blinking, disconnect the distributor connection and check for pulsing/blinking on that BL/O wire while cranking. If there is a continous ground at the ICM, continous current through the coil, then there can be no spark. If the ECA was a known good unit, this would be easier: no signal from the CKP sensor and it would be that component or circuit; a good SPOUT signal and it would be the ICM or coil or circuits as others have suggested. If you get no pulsing on the SPOUT BL/O wire when disconnected, there is still the possibility the CKP signal is not making it to the ECA as you said, and also all ECA terminal connections quality. I'm not sure if the ECA ground connection (and maybe B+) has been addressed by anything at this point, unless those injectors aren't grounding. I'm going back and look at that now. Take no offense at anything I've said that you already know because I'm trying to keep a continuity and clarity here.

[tooldude]

I just realized, you never said if that LED light is a high impedence (low current draw) tester. Was there any specs/data with it? It sounds like the right thing, but you need to know before connecting on the solid state stuff. Also, the digital meter you have is safe if it's at least 10 MegOhms impedence. The catch with cheaper DVMs is low accuracy but usually have the high impedence. Many times you don't need a lot of accuracy just need the continuity or relative voltage.

[tooldude]

The injectors: I'm seeing where you found voltage going to the injectors Y/BK wire but unless I'm not seeing something, that's not the end of it. You need to determine the injectors are actually being grounded by the ECA by checking on the ECA side of the injectors with that high impedence tester. Without engine cranking or running, the injectors should be ungrounded. You should be seeing voltage on that side, then, in a static circuit. Once the ECA grounds them, you should then see ground with your tester. Of course that would be for both pairs, the GN/Y and the GN/BK wires. If injectors and spark are both out, I believe the last hope is B+ and ground before condemning the ECA.

[burnt_toast]

Hell yeah, now thats some info I can sink my teeth into. Viewing on my phone right now so bear with me on the spelling. To answer tha main questions:

There is no pulsing signal when testing the SPOUT wire at the ECA. To be specific, it does dim and brighten oh so slightly when cranking. It dims slightly though when you flip the key on. It does that with everything though. Even a wire that is hot at all times will dim and brighten whike cranking. When I tap into the CKP wire coming off the dizzy... Now THAT is blinking.. Its definitely diferent.

On the logic probe: there isnt much info but they say it draws less than 7ma and does 6,12, and24v systems.

On the injectors, if Im probing the ground wire to the injectors and getting nothing isnt that nornal? Are tou saying it should be grounded at all times abd BREAKING the ground is what causes the pulse? I thought it was the other way around.

I can make a jumper for the relay if you still dont trust it, but if its failing shouldnt even more be going wrong? Doesnt the main relay control multiple items? Either way, I can make a jumper... I have 18ga wire and a aoldering gun along with a drawer full of fuses. I have some blade connectors but they are probably the wrong type. I dunno until i check tho. Ah to hell with this I need to fire up my lap top. Its impossible to follow all this on this little screen.

[1chrisapple]

boy i hope you get this figured out by now I would of sold it.

[burnt_toast]

Sold it? I will NEVER sell this car. I will drive it until it is impossible to purchase or fabricate parts, then gut it for scrap and make the body into a flower bed/lawn decoration. I haven't even ruled everything out yet? How could I give up and sell it? It could be the ECA? It could be the relay? The real dread would be pulling the dash out to open a wiring loom or some insane task like that. Now THAT would test my resolve.
-toast

[burnt_toast]

So you probed the BL/O SPOUT wire and you get ground under all conditions, green at all times? Was that light blinking when you crank the engine or steady? The SPOUT signal is supposed to trigger a ground for each spark so the light should blink. If it is blinking then check if you have spark now. If it's not blinking, disconnect the distributor connection and check for pulsing/blinking on that BL/O wire while cranking.

SPOUT wire at the ECA was not blinking. I have not idea why I would disconnect the dizzy and check for pulsing, but I will do it (doubt I can until tomorrow though).

'm not sure if the ECA ground connection (and maybe B+) has been addressed by anything at this point, unless those injectors aren't grounding.

I haven't checked the ECA grounds yet. I really haven't done any ECA testing except for the two checks I mentioned previously with it's SPOUT wire and checking the pulse signal leaving the CKP sensor (which is the closest I could get to finding that wire at the ECA, it's a pain to reach that component and even harder to get light in under the dash).

Also, the digital meter you have is safe if it's at least 10 MegOhms impedence.

I mentioned before the LED logic probe is less than 7ma according to the website. There is no mention of ohms whatsoever. The multimeter is harder to tell. This is the one I have:

http://www.harborfreight.com/7-funct...ter-98025.html

I don't see anything about impedance. In the manual it has a warning "Do not test current on circuits higher than 200 mA." Wait, in the manual's specifications it give it's resistance range as:

Ranges:
200/2000/20K/
200K/2000K Ohm

The injectors: I'm seeing where you found voltage going to the injectors Y/BK wire but unless I'm not seeing something, that's not the end of it. You need to determine the injectors are actually being grounded by the ECA by checking on the ECA side of the injectors with that high impedence tester. Without engine cranking or running, the injectors should be ungrounded. You should be seeing voltage on that side, then, in a static circuit. Once the ECA grounds them, you should then see ground with your tester. Of course that would be for both pairs, the GN/Y and the GN/BK wires. If injectors and spark are both out, I believe the last hope is B+ and ground before condemning the ECA.

I used the logic probe on both wires at the injector harness connector. Solid, unblinking red on one wire, nothing (no light) on the other. That's with all 4 disconnected. You're saying to go to the ECA side of the wiring and check there? Ok. I'll go through the schematic and try to find the correct wire and crawl under there again. I don't see what you're looking for though; if there is no signal where the injectors connect all I'm doing by crawling under the dash is verifying the wire from the ECA to the injector is good. I'm interested in the ground and voltage tests. You mentioned them near the beginning, but at the time I did not have the schematic and didn't really understand where to look.

-toast

[tooldude]

I missed your comment about the tester pulling 7ma. That is really great, lowest I have seen is about 19ma. You can put that probe on anything. You just sold one for them. I'm trying to keep you from under the dash, if possible, that's a tough place. Before even starting on this, have you checked for spark, do you have spark right now? I'm working from the assumption you don't have spark yet. I'm trying to find you definitive tests that get away from probing hard to access points unless absolutely necessary. You may not need to do these tests. On the SPOUT wire: Dang, working without sleep, I left out part of the wording, mixing two different ways of testing, trying to get you an easy connection. If you unplug the distributor and jumper all the wires except BL/O, you can test the BL/O wire THERE ON THE PLUG (while cranking), this will tell you if the SPOUT signal is making it to the ICM. (In the schematic the wire doesn't appear to change color). Then I thought it might be too hard to jump those conections. The main reason for this test is it's unclear whether you have a continous ground (at the ICM) which would mean something is shorted. If the SPOUT wire is disconnected you should see a pulsing(blinking) voltage on your light when probing it(engine cranking). This is the signal that is supposed to be generated from the CKP sensor input. I'm not sure if you did a cranking test before on the BL/O wire, there should be a blinking/pulsing there, even with it connected. I don't know if you can backprobe that distributor connector, I was trying to get you around it. On the injector wires-Easy Test: you had all 4 injector plugs disconnected previously to see if voltage was getting to the injectors via the Y/BK wiring (which it was) and there was nothing on the other wire/s. That condition is as it should be, because there should be no grounding without the engine cranking/running or else there would be an internal ECA short of the injectors to ground. Now you can test each injector pair for proper grounding through the ECA, by probing each wire, GN/Y and GN/BK, WHILE THE ENGINE IS CRANKING. That's the ECA side of the wiring, connected to the ground side of the injector coils, and where you can easily test.

[burnt_toast]

Now you can test each injector pair for proper grounding through the ECA, by probing each wire, GN/Y and GN/BK, WHILE THE ENGINE IS CRANKING. That's the ECA side of the wiring, connected to the ground side of the injector coils, and where you can easily test.

I did that at the connectors to the injectors. All 4 unplugged, then tested the #1 wire (GRN/YEL) and got nothing. No solid light, no blinking light... nothing. Nothing OFF. Nothing ON. Nothing START.

As for checking for spark. I have an inline spark tester on the #1 spark plug:

http://www.harborfreight.com/inline-...ker-69014.html

I guess technically I've never checked to make sure the bulb works because putting 12V through it doesn't do anything. I assume it's wanting much higher voltage than the battery can give it. The last time I checked for spark by grounding the plug to the valve cover was when I put in the new ICM. I have not changed anything mechanically since that time so I feel it safe to say there is still not spark.

As for jumpers after disconnecting the wires to the dizzy, I just left it plugged in and jabbed through the insulation of the wire in order to check for voltage. The pulse wire there is pulsing when the engine is cranking (it's a brand new distributor also by the way). I think I'm failing to understand the test you want me to perform. You must have some reason for needing to have 2 of the wires to the dizzy disconnected but not the 3rd in order to test the ICM, but that has gone completely over my head. In fact let me stop even trying to explain what I'm thinking for fear of throwing this off.

I get the injector test. I believe I did it exactly the way you described it (post #91 paragraph 1-2). So no injector pulse. I am not understanding the other spark test. It sounds like tests I've already done, Certainly the ICM should not need tested again... it's new. Ditto the distributor/CKP. Ditto the coil.
-toast

[tooldude]

Unless there's something I don't know, with a good signal from the CKP sensor and yet no grounding of the injectors, that alone seems like it would present the ECA as defective doesn't it(?), UNLESS signals are not getting where they need to be. This is what I have been trying to ascertain from your tests, and from my suggestions. I don't want to rashly say that computer is defective but at this point, it does seem to be, as you were thinking. I would hate to see you replace it and have the same problem. So do you have a loaner there to swap out? That might be the best thing to do at this point. It doesn't seem like a B+ feed or a ground problem fits these results but I'm still wondering about the ECA connectors. If those should need cleaning, I don't know the safe way to do that, I need to find out myself. A thought, if that ECA has failed why did it fail? I don't know every reason, one, boards can crack, but an alternator regulator problem can ruin one by not only getting an over-voltage, but actually too much ac voltage getting through the rectifiers can do it. You might check that.