83GLwgn Posted November 26, 2007 Share Posted November 26, 2007 Greetings all, My wagon keeps blowing the Ignition/Fuel fuse #12. While driving on the freeway, it stuttered going uphill then recovered, only to lose power. I gave it gas and it continued to run long enough to get to an exit (mine thankfully) and coasted to a side street. The engine would die if I backed off the throttle and would run barely if I popped the clutch in gear and gave it gas. Once I stopped it would crank but not start. No obvious trauma anywhere. Checked fuses and # 12 was popped. Installed a spare and she started and died within a second. Did the same thing with a second spare. Tried turning the key to 'on' and the dash lights dimmed and the third spare fuse popped w/i a second. My neighbor towed it home for me. I unhooked the coil and fuel pump - blows the fuse. I unhooked the fuel pump control unit - blows fuse. I tried areas mentioned in other posts for common shorts (choke, radio) and saw no signs of arcing or crispiness. My Haynes manual wiring diagrams do not entirely match my car. Where or what else should I check? What else is energized with the key in the 'on' position? Link to comment Share on other sites More sharing options...
Gloyale Posted November 26, 2007 Share Posted November 26, 2007 Bolted to the drivers side kickpanel, near the hood release is the revolution sensor. I had a bad one blowing this same fuse once. Has six pole connection and a Mitsubishi looking 3 diamond logo on it. It won't allow power to the fuel pump, anti diesel soenoid, and auto choke heater to have power unless it senses ignition pulse. Link to comment Share on other sites More sharing options...
83GLwgn Posted November 26, 2007 Author Share Posted November 26, 2007 Bolted to the drivers side kickpanel, near the hood release is the revolution sensor. I had a bad one blowing this same fuse once. Has six pole connection and a Mitsubishi looking 3 diamond logo on it. It won't allow power to the fuel pump, anti diesel soenoid, and auto choke heater to have power unless it senses ignition pulse. OK, I thought that was the fuel pump control unit. It is unplugged, and still blows the fuse. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 27, 2007 Share Posted November 27, 2007 OK, I thought that was the fuel pump control unit. It is unplugged, and still blows the fuse. That is the fuel pump control unit - RPM sensor is another term for the same device. That doesn't seem to be your problem, but I thought I would clarify. GD Link to comment Share on other sites More sharing options...
83GLwgn Posted November 27, 2007 Author Share Posted November 27, 2007 That is the fuel pump control unit - RPM sensor is another term for the same device. That doesn't seem to be your problem, but I thought I would clarify. GD OK. Thank you, that helps clarify the manual a bit. I found some oxidation on the ignition switch terminals and wire brushed everything clean - no change, still pops the fuse. No signs of anything abnormal on the back of the fuse block, or anywhere I can see under the dash. ??????? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 27, 2007 Share Posted November 27, 2007 Unfortunately the #12 fuse runs a LOT of stuff. I'll try to make a list for you from my wiring diagram: 1. Coil 2. Ignitor (inside distributor) 3. Gauge cluster (all the insturments) 4. Fuel level sender * 5. Brake fluid level sensor 6. Stop light switch * 7. Stop light checker module 8. Oil pressure sender or switch * 9. Anti-dieseling solenoid * 10. Vent solenoid 11. Stop switch (cruise control) * 12. Clutch switch (cruise control) * 13. Door ajar switches (all of them) * 14. Clock 15. Timer (seat belt chime, key warning) It could be any of those, but I would start looking at door ajar switches, and the pedal switches, etc. Anything that moves a lot and could be exposed to the elements. To start with, stop blowing up fuses. Hook up a 12v lamp (headlamp, or tail lamp, etc) to the fuse location. Since it's shorted it will glow at full brightness and will add enough resistance to the circuit to not harm the wiring. Start disconnecting components till the bulb dims or goes out. Then start reconnecting all the *other* components to make sure it's not some part of the wiring supplying more than one component. This will help you isolate the fault. I put a "*" next to the stuff I would be checking first. GD Link to comment Share on other sites More sharing options...
83GLwgn Posted November 27, 2007 Author Share Posted November 27, 2007 Great! Thank you GD. I am on it right now. Link to comment Share on other sites More sharing options...
Cougar Posted November 27, 2007 Share Posted November 27, 2007 There may be a clue to the trouble area since the engine was having trouble before the fuse blew. Try disconnecting the coil and ignitor connections and see if the there is still a short on the fuse line. If that doesn't help then try the anti-dieseling solenoid. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 27, 2007 Share Posted November 27, 2007 If that doesn't help then try the anti-dieseling solenoid. Yeah - that's a common one. Those always have broken insulation at the least it seems. GD Link to comment Share on other sites More sharing options...
83GLwgn Posted November 27, 2007 Author Share Posted November 27, 2007 Yeah - that's a common one. Those always have broken insulation at the least it seems. GD Thanks for the awesome help! Either the bowl vent solenoid valve or the anti-diesel switch is bad. Is there any way to test them? Now, I presume it will be okay to drive without the anti-diesel since I can stall the engine when I stop. But what about the bowl vent? Will that create a dangerous situation or affect drivability? Link to comment Share on other sites More sharing options...
TomRhere Posted November 27, 2007 Share Posted November 27, 2007 Bowl vent solenoid allows the fumes from the float bowl to be drawn into the vapor canister to be burned by the engine. Shouldn't effect driving at all. Anti-deisel valve will effect driving. Engine won't run if valve doesn't open. Valve shuts off fuel flow with key "off" to keep engine from running on, "deiseling". Check the wiring on the carb for any cracked insulation, that stuff gets brittle with heat and age. No idea what the ohm reading of either should be. But you can check them with a multimeter for dead shorts. Link to comment Share on other sites More sharing options...
83GLwgn Posted November 27, 2007 Author Share Posted November 27, 2007 Bowl vent solenoid allows the fumes from the float bowl to be drawn into the vapor canister to be burned by the engine. Shouldn't effect driving at all. Anti-deisel valve will effect driving. Engine won't run if valve doesn't open. Valve shuts off fuel flow with key "off" to keep engine from running on, "deiseling". Check the wiring on the carb for any cracked insulation, that stuff gets brittle with heat and age. No idea what the ohm reading of either should be. But you can check them with a multimeter for dead shorts. OK, thanks. The wires looked good until I started messing with them - the insulation is brittle. The connector also feeds the choke, so maybe I can push a pin to isolate the other two valves. Where is my electrical tape? Link to comment Share on other sites More sharing options...
83GLwgn Posted November 27, 2007 Author Share Posted November 27, 2007 Success!!! Pushed the pin out of the connector and taped it. Everything back together and it starts and runs. Going to bed so the test drive will have to wait until later. Thanks to everyone for their help. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 28, 2007 Share Posted November 28, 2007 Yeah - the anti-dieseling solenoid requires power to allow the idle circuit to get fuel. If it's left unpowered the car will run but will die when the choke pulls off and the carb needs the idle circuit again. GD Link to comment Share on other sites More sharing options...
83GLwgn Posted November 28, 2007 Author Share Posted November 28, 2007 With the bowl vent unhooked, it runs but seems to have a hiccup occasionally, especially at higher speeds. Throttle response is crisper. She had started stalling when I stopped in traffic or at lights, so the idle was cranked up a bit. I was able to turn it down a little, but not to where it should be. I thought it was due to wear around the throttle shafts, but it could be the anti-dieseling solenoid also. How does the anti-dieseling solenoid work? It looks like a spring-loaded plunger and the 12v pulls the plunger into the solenoid and allows fuel to pass? So resistance of the coil should be low? And I should be able to test by removing the solenoid from the carb, grounding it and jumpering 12v to the wire? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted November 28, 2007 Share Posted November 28, 2007 How does the anti-dieseling solenoid work? It looks like a spring-loaded plunger and the 12v pulls the plunger into the solenoid and allows fuel to pass? So resistance of the coil should be low? And I should be able to test by removing the solenoid from the carb, grounding it and jumpering 12v to the wire? Exactly. GD Link to comment Share on other sites More sharing options...
83GLwgn Posted December 3, 2007 Author Share Posted December 3, 2007 Update. The bowl vent valve solenoid is shorted. I realized I didn't mention the cause above. It runs, but not well and is really thirsty. I have a bog when the secondary (Hitachi) opens and it feels like I have a vacuum leak. Can I disconnect or plug the hose from the bowl vent valve without serious consequences? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted December 3, 2007 Share Posted December 3, 2007 Can I disconnect or plug the hose from the bowl vent valve without serious consequences? Should be able to, yeah. It just might deisel. Or you can get another solenoid - should be expensive from the JY. Or put on a Weber. GD Link to comment Share on other sites More sharing options...
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