Hello, I've been banging my head trying solve a no start issue with my 1991 Subaru Sambar carburated. It started after a long drive, seemed to be running a bit rough at higher rpm, parked it for a couple hours, then would not start. From then to now, the truck will not start at all, just cranks. After some initial troubleshooting, it seemed like the fuel pump might have died. I replaced it with the OE part, but that did not solve the issue. I had recently replaced the spark plugs, distributor rotor and distributor cap, and had been running great for a few weeks so didn't immediately jump to no spark. After verifying that the fuel pump was pumping with the key in ON (also found fuel in the cylinders), and testing compression, I decided to check spark. Checking for spark on the truck revealed that the plugs were not sparking when cranking. At this point I started checking voltages with my multimeter. I did validate I have no blown fuses in the cabin fuse box, no blown fuses in the box behind the battery. I did rebuild the carb recently, did replace the solenoid. I did also test the resistance of the plug wires, they seemed to be appropriate values. When the key is in ON, near 12v on the Black/Red wire going to the ignition coil 0v on the yellow wire 12v at the ceramic resistor before the coil 12v at the black/white wire on the fuel pump 0v at the black wire on the fuel pump Took a bit of research to realize that I should expect 12v on the 0v wires when cranking So at this point I tested the voltages with key in START. still 0v on the yellow wire at the coil still 0v at the black wire on the fuel pump It was about the 10th time re-reading the wiring diagram I found in another thread that I realized, the wires that I was getting 12v on at key ON, should be the wires getting 12v at key START, and vice versa for the 0v wires. Basing this off of the colors in the wiring diagram. It could be that I am misinterpreting the diagram? But something seems off and I cannot figure out what is going wrong. Any advice is appreciated
First thing I would do is replace the engine fuse. I have run around in circles before because I looked at a fuse and it looked good, but after I spent a couple of hundred dollars on parts and several hours in sweat, only to find that when I put an ohmmeter on the fuse, it was not good. You can always run a 12v wire straight from the battery to the coil (or to the resistor if it has one) for diagnostic purposes. If it runs when you hotwire the coil, it's likely your ignition switch. Edit. I see you said it had a resistor, did you check it?
I did check all the fuses with my multi-meter, all tested ok. I tested the resistor too, it seems ok. Yesterday after digging deeper, I found that the points in my distributor are worn out, will replace those as it seems to be the most likely cause of the no spark issue. I must be misunderstanding the wiring diagram and reading what should have voltage backwards.
