SC Won't Start

[na2ub]

My 79 SC didn't start the other morning after sitting in the driveway in the snow (sorry). The engine turns over and will light up for a second every 6 or 7 times. I replaced the fuel filter, but it did not help. I checked for spark at the coil, but it appeared ok. I don't know if it is the pump, I had it replaced two years ago, and when I changed the filter, it was full and under slight pressure. The exhaust / airbox emit a vapor, a little gas smell, but mostly a dirty / dusty smell. Any suggestions? I am planning on turning on the ignition and disconnecting the fuel filter to check flow. Other that that I am stumped. Maybe the distributor?

Thanks for any tips.
Doug

[MotoSook]

With the ignition on and the fuel pump running, push up on the air sensor plate and you should hear a high pitch whine when fuel goes through the injectors. If it sound like that you should have some (maybe enough) fuel pressure. Do this only for a few seconds and you don't need to lift the sensor plate very high.

Does your CDI box whine also? Can you hear the fuel pump? It should whine also. Boy we have whiners for cars don't we?

give it a try report back.....

[Superman]

I always suspect ignition first. In the olden days, that was nearly always the problem. Nowadays, fuel systems are just as unreliable. Still, I'd make darned sure the distributor cap and rotor are dry as bones. They'd spend the night in my house. I might also just install new plugs. Further, you can hook your timing light up and see if it is flashing during the starting procedure. A spark outside the cylinder does not necessarily mean that it is also sparking under compression, in the cylinder. Ignition systems are persnickity.

Once that is verified, then I would move to the fuel system. Run the fuel pump by itself for a few minutes first. Check fuel pressure if you can, and fuel volume, as you suggested. Pull an injector, run the pump and push up on the air flow sensor plate. It should spray. If all that is happening, then check the cold start system.

[surflvr911sc]

First thing JW seems to say when bad weather is involved, check the distributor for water.

[na2ub]

Thanks for the input. I have to quit for the night (blame a female), but I will try your suggestions tomorrow - Distributor cap first. When the car is outside, doesn's all the rain / wet just drip over the engine through the grill? Also, where do I locate the air flow sensor plate. I am not familiar with such.
Thanks,
Doug

[MotoSook]

Take your intake/filter housing off. and look under the robber boot. it is there, attched to the fuel plunger arm. Push up slightly.

I have to agree that ignition is seldom overlooked and fuel is often blamed for poor ignition.