1998 Chevrolet Astro

98 astro van will not start. The problem started about a year ago in cold weather car began to struggle and code came up with multiple misfire I replaced the distributor, cap and rotor. It ran then started having problems again and wouldn't start I replaced the coil. It then came up with p0420 bank 1 catailyst inefficient I replace catalytic converter and it ran great for about a year. Then in the cold again it started misfiring and stalling I found that the year old coil was arcing so I replaced it and the coil wire. Ran fine with what seemed to be occasional misfire one day but next day it would run fine. THen the p0420 code began to appear again if I reset the engine lighe and warmed the car up or it was warm out it would not come on but then if it was cold and not warmed up before driving it would reappear, then 2 days ago it wouldn't start at all. I have spark from coil to rotor and to the plugs appears. I have 60psi on fuel line. I sprayed starting fluid in intake to see if it would fire and nothing happened. Im lost on what it could be or what to do.
January 14, 2011.

First, the PO420 can be an O2 sensor that isn't working properly. If you have a scanner, at operating temp, the sensors should be moving between.35 and.55 volts. If they are out of that spec, that is most likely causing the PO420 and not a bad converter. Next, if you have spark and it doesn't start with starting fluid, you must have a really weak spark at the plugs. The spark should be a hot blue snapping spark. If it is white, orange. It is weak and the vehicle will not run or run really bad. In that case, I ask that you ckeck the condition of all plug wires, the cap again, rotor, and plugs. If they all look good and there are no other codes, check the crank sensor for its condition.

If you have good spark, good fuel pressure and it will not start, make sure the injectors are working. (Based on the no start with starting fluid, this is a last resort). You will need a noid light. Most parts stores will lend them to you. It just plugs into the wiring to the injector. Have a helper crank the engine and you should see the light pulse on and off when it gets power. If there is no power, trace wiring back to the pcm for damaged wires and check the PCM for power to the injectors.

One last thing. If you have good spark, fuel, and it still won't start even with starting fluid, check engine compression and timing.

I have replaced the 02 sensors the spark appears to be an orange color more than blue going into the distributor how do I check the coil to be sure it is the second coil in 1 year

Jan 14, 2011.
If you are getting an orange spark, you need to have the coil checked. You need to check the ohms between the - and + as well as to the output.