Starting Issues

[cybercj_btw]

I have an 86 Power Ram 50 with the 2.6L and stock Mikuni carb that has sat for years. I got the carb rebuilt and have some issues. For starters, I currently do not have an ignition lock and key cylinder, to start the truck I am sticking a key in the ignition switch itself. First problem I see is that if I open the throttle, I do not see any gas coming into the carb. When I go to start it (pouring gas into carb) it will start but die the second I return the ignition switch to the on position. As long as the starter is going it continues to run. I have all of the fuel lines run to the carb but do not see any fuel going into it, yet my mechanical fuel pump is brand new and works. I cannot tell if this is a carb issue preventing it from idling or if the ignition switch needs to be in the cylinder to idle. Regardless I have a brand new ignition switch with the cylinder on the way.

[FMS88]

Fix the ignition switch first then address the other problems. The ignition system has to be working reliably before tackling carb and fuel delivery issues.

[SubGothius]

Only starting/running with the key switch in the Start position, but dying in the Run position, suggests to me you might have a failed ballast resistor on your ignition coil.

You might be able to find a replacement ballast resistor, but if you've still got your original stock coil you may as well replace that as well, which should come with a new ballast resistor -- the Herko B108 coil does, and is pretty good and cheap:

https://herko.com/Retail/catalog/product/view/id/726

I would up dis/reassembling the mounting bracket on mine to flip the coil position around for easier/tidier wire routing. Here's a good thread about the resistor and coil wiring:

http://www.mightyram50.net/vbulletin...on-coil-wiring

[cybercj_btw]

I have a brand new coil I just installed, as for the resistor, I think it is ok. I have two 86 d50s and I tried both resistors and got the same product. I also tested the resistor with a multimeter to make sure current was flowing through it. If there is a problem with the resistor how would I be able to tell?

[SubGothius]

I wondered about the ballast resistor/coil wiring because during cranking, a different wire supplies power to the coil than during normal running. That different wire for cranking is connected to the coil side of the resistor, so it bypasses the resistor to provide a full 12V to the coil for a hotter spark to assist in initial startup. For normal running, power is supplied to the other end of the ballast resistor, which drops the effective voltage to the coil to prevent burning out ignition components prematurely.

With the key in the Run position, are you getting any voltage to the terminals on the ballast resistor? You should see ~12V at the end of the resistor opposite the coil, and something less than 12V at the other end of the resistor that's wired to the coil. If you got nada, then something isn't allowing power to the coil during normal running. Maybe a bad ignition switch (the electrical part, not just the key lock cylinder), or a failed fusible link, or faulty wiring, or maybe something else.