Hi, I have a 1997 Cadillac Deville. I had a charge issue which forced me to take the battery out and have it tested. The battery was good so decided I needed an alternator. Left battery out of vehicle until the weekend (4 days). Replaced the alternator yesterday and put new battery in regardless. Now the vehicle will not start. It will crank all day long but will not start. There is a security light on the dash that keeps blinking. Can the pass key system lose memory and cause my keys to become unprogrammed? And if so, can I reprogram them without having it towed to the dealer so they can use their scanner to do it. I read about the run position for 10min and then cycle ingnition and wait for 10 min etc... but will that work having had the battery out for so long and memory being wiped from my modules?

The modules should not loose their memory. When you turn the key to run, can you hear the fuel pump? If so, check for spark at the spark plug.

I cant recall. I will check that and the spark and report back. Thanks Dan!

Ok, I have checked for fuel and fire and have both. Tried to do the key program deal too but didnt work.

OK, so you have fuel pressure, and spark, and the engine cranks but no start. If you can pull a spark plug, is it wet, if so that tells me your flooded. Floor the gas and hold it there. Then crank it with your foot on the floor. It will take a long time but it should fire. It may do this several times before it actually kicks over and starts to run.

Blinking security light is good, not bad.

Ok, so when I "checked" the fuel pressure, my method was to press the needle in on the service port on the rail. Big mistake.... Tonight, I actually installed a guage. Zero pressure when the key is turned on (yes the pump hums for three seconds). When I crank, no pressure still. So I took the fuel line off of the filter (from pump to filter) and turned the ignition on to see if it was the filter that was clogged. I dangled the fuel line coming from the pump into a jar. Turned the ignition on and the pump (mmmmmmmmmmmmm) and I got a thimble full of fuel out of it. Did it again. mmmmmmmmm and a thimble of fuel.... The fuel was cloudy with crap in the bottom. Could the sock filter be clogged and be causing the pump to perform poorly? Is my diagnosis procedure proper. The pump should be putting out more fuel than a thimble fuel right?

Try replacing the filter. If that doesn't fix it then the pump is not working right. You should have around 48 psi with key on