dangerous Posted December 1, 2014 Share Posted December 1, 2014 Wondering if I've got this right. I got a reading from pin1 positive to pin 2 neg, and pin 2 neg to pin 3 pos. Thinking since I have power, and no spark from the coil that the coil may be fried? But not sure because of not knowing what should be coming from what on the coil plug? Link to comment Share on other sites More sharing options...
Gloyale Posted December 1, 2014 Share Posted December 1, 2014 Center wire (yellow) is 12v switched from the Ignition. Outer 2 are the triggers from the Ignitor(blue + red IIRC) Link to comment Share on other sites More sharing options...
dangerous Posted December 1, 2014 Author Share Posted December 1, 2014 (edited) So should I be grounding the neg to the block or something? Then go turn the key to on? The starter is runnin just no spark through the coil Edited December 1, 2014 by dangerous Link to comment Share on other sites More sharing options...
upnorthguy Posted December 1, 2014 Share Posted December 1, 2014 I went through some coil troubleshooting a couple of months ago (it wasn't the problem, but that is another story...see page 3 of this thread for coil discussion). After much help from Fairtax4me, I was checking coil voltage with red lead on middle yellow ignition wire and black lead to battery negative when key is on. Link to comment Share on other sites More sharing options...
dangerous Posted December 1, 2014 Author Share Posted December 1, 2014 (edited) I went through some coil troubleshooting a couple of months ago (it wasn't the problem, but that is another story...see page 3 of this thread for coil discussion). After much help from Fairtax4me, I was checking coil voltage with red lead on middle yellow ignition wire and black lead to battery negative when key is on. UNG don't have anyone to help, but even without cranking the engine seems there is a complete circut going of about 1.5 ohms on the center pin and 4.5 on either side Edited December 1, 2014 by dangerous Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 2, 2014 Share Posted December 2, 2014 Resistance readings don't mean anything unless you totally unhooked the circuit you were testing. You can not check resistance on a live circuit and expect to get the correct result. 99% of the time the coil isn't the problem. Check for 12v at the center pin with key On. Ground one of the other pins via test light of jumper and the coil should fire once the ground is broken. Its best to use a spark tester or an extra spark plug stuck in the end of a plug wire. Crankshaft and camshaft sensors both need to work to get spark. Failure of either of those will result in no spark condition, and are much more common than a failed coil. Link to comment Share on other sites More sharing options...
dangerous Posted December 2, 2014 Author Share Posted December 2, 2014 (edited) Fairtax4me which wire pins do I need to check on the crank and cam shaft sensors? Put in a salvaged coil and got nuthin. Should I also check the voltage from the ignitor while trying to crank the engine, and do I need to crank on the other sensors also? Just checkt n no power from the ignitor when trying to crank Edited December 2, 2014 by dangerous Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 2, 2014 Share Posted December 2, 2014 The ignter isn't powered. It grounds the coil circuit. I dont know the pinout offhand but you should have 2 signal wires from the ECU, 2 wires from the coil that should both read 12v with key On. These will change when ranking and will not yield a consistent reading on a voltmeter. The last wire is ground IIRC. Cam and crank sensors make AC waveform signals. Back-probe both pins on the sensor and check for AC voltage while cranking. It will be low voltage. The ECU isnt concerned with the voltage from these, it's the waveform that matters, and you can't see the waveform with a voltmeter. If both produce AC voltage then they're probably OK. You can also unplug them and check resistance but I don't know the spec offhand. Link to comment Share on other sites More sharing options...
dangerous Posted December 3, 2014 Author Share Posted December 3, 2014 FT4M wondering how easily the cam n crank sensors can get fried? In the manual it says not to keep trying to start the engine more than 10 seconds it it won't start. Well we may have done that in trying to figure out power leads, because this whole thing started out with what we thought was a bad fuel pump but is probably a bad wire. Plus tried two diff fuel pump relays n still had the same problem, but the pump works fine hotwired through a fuse. Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 3, 2014 Share Posted December 3, 2014 (edited) They won't fry themselves if that's what you're thinking. The fuel pump should run for 2-3 seconds when the key is turned On to prime the system. Is it not doing that? Edited December 3, 2014 by Fairtax4me Link to comment Share on other sites More sharing options...
dangerous Posted December 3, 2014 Author Share Posted December 3, 2014 (edited) No it is not doing that even after changin out two different fuel pump relays and a pump that works. The old pump also worked when we jumped it off the battery. The main problem being that there is still no spark even with the other coil, and the fact that there is power from the ignition. Also on Sat when we jumper the fuel pump from the fuse it ran like a charm for the 25 miles it takes to get home up steep grades. Messed with it Sun, and went to just having it run on the fuse and it wouldn't start n no spark Edited December 3, 2014 by dangerous Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 3, 2014 Share Posted December 3, 2014 ECU grounds the fuel pump relay in order to turn on the pump. ECU also grounds the igniter signals which tell the coil to spark. On the passenger side of the engine are a handful of electrical plugs, the largest (16 pins IIRC) has 4 ground wires across the bottom row. I want to say they're all black with white stripe but I don't remember exactly. Those ground wires are all for the sensor and driver circuits of the ECU. If any of those plugs is dirty or corroded inside or the plug is loose (not clicked together all the way) you get all kinds of odd problems. Check those for clean tight connection. Link to comment Share on other sites More sharing options...
dangerous Posted December 4, 2014 Author Share Posted December 4, 2014 (edited) FT4M I checked that plug n all looks good also changed the cam n crank shaft sensors n still got nuthin! My friend had also tried to jump the fuel pump relay on Sun causing a spark. Would that have fried something? Edited December 4, 2014 by dangerous Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 4, 2014 Share Posted December 4, 2014 It would just blow a fuse. Have you checked all of those? Be sure to check the ones under the hood too. Link to comment Share on other sites More sharing options...
dangerous Posted December 4, 2014 Author Share Posted December 4, 2014 (edited) Yeah all fuses have been chkt. Wonderin if it could be the fusible link in the fuse box under the hood? Edited December 4, 2014 by dangerous Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 4, 2014 Share Posted December 4, 2014 If the main fusible link blows you will get a no-crank situation since that's what supplies power to the ignition switch. You would have basically no electrical power at all inside the car. The coil, fuel pump, and ECU and TCU all get power through fuse 16 in the dash fuse panel. Double check the fuses there. Link to comment Share on other sites More sharing options...
dangerous Posted December 6, 2014 Author Share Posted December 6, 2014 (edited) FT4M for what reason might we not be getting power to the red wires on the main, and fuel pump relays? Have power to yellow wire on fuel pump relay, but none on the red. Would running a jump wire from fusible like to the main, and fuel pump relays fry anything else? The schematics show 1 red wire coming from the fusible link and splitting into 3 that go to those relays. My friend thinks the problem might be at the junction where the red wire splits coming from the fusible link to the main, and fuel pump relays and over to the fuel pump? Is that a pain in the neck to get at? Edited December 7, 2014 by dangerous Link to comment Share on other sites More sharing options...
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