CptStickfigure
09-09-2004, 04:58 PM
The short version here is that my car won't start. The engine ran before I messed with it, but it's old and was poorly maintained, so something may have just caught up with me. I've been doing a lot of electrical work (12 volt conversion and a complete rewiring), so I'm guessing that's where the problem is, but I'm running out of ideas.
Since ignition questions seem fairly common, I wonder if we could turn this into a sort of checklist of things to look for, easiest/most likely solutions first. If you've had starting trouble before, how about giving us your symptoms and solution.
On to the specifics. This is on a splash oiled Chevy 235 with a stock Rochester BC carb if it makes a difference.
Symptoms:
The engine cranks, but never really fires. If I really lean on it with the air cleaner off, it'll sort of pop and spit back through the carb, and maybe give me a little backfire or smoke.
Electrical:
-I installed a new generic ignition switch to cut the separate starter button and ignition switch out of the equation.
-Currently wired without gauges, so that shouldn't be an issue
-Replaced and gapped points and spark plugs
-Using an internally resisted 12v coil, so no external ballast resistor
-Voltmeter shows 12 volts at the battery
-Ohmmeter shows a good ignition circuit
-I've got power to the coil
-I've got sparks across the point gap
-Coil/Plug spark seems weak
Fuel:
-Put fuel in the tank (it was empty on the first try)
-Poured a little gas down the carb throat
-Gave it a few shots of carb cleaner
-Monkeyed with idle speed screw (back and forth until I got consistent promising results)
At this point I'm guessing grounding, timing, compression, or bad distributor, but I not sure what I'm looking for.
Since ignition questions seem fairly common, I wonder if we could turn this into a sort of checklist of things to look for, easiest/most likely solutions first. If you've had starting trouble before, how about giving us your symptoms and solution.
On to the specifics. This is on a splash oiled Chevy 235 with a stock Rochester BC carb if it makes a difference.
Symptoms:
The engine cranks, but never really fires. If I really lean on it with the air cleaner off, it'll sort of pop and spit back through the carb, and maybe give me a little backfire or smoke.
Electrical:
-I installed a new generic ignition switch to cut the separate starter button and ignition switch out of the equation.
-Currently wired without gauges, so that shouldn't be an issue
-Replaced and gapped points and spark plugs
-Using an internally resisted 12v coil, so no external ballast resistor
-Voltmeter shows 12 volts at the battery
-Ohmmeter shows a good ignition circuit
-I've got power to the coil
-I've got sparks across the point gap
-Coil/Plug spark seems weak
Fuel:
-Put fuel in the tank (it was empty on the first try)
-Poured a little gas down the carb throat
-Gave it a few shots of carb cleaner
-Monkeyed with idle speed screw (back and forth until I got consistent promising results)
At this point I'm guessing grounding, timing, compression, or bad distributor, but I not sure what I'm looking for.