O2 shouldn't have anything to do with starting. Does affect how the engine runs once it has been running for a few minutes though.

Should be able to rent a fuel pressure gauge from your local big chain auto parts store. You get your money back when you return the gauge.

Having a scanner that can read live data sure wouldn't hurt either.

 

Since starting fluid made no difference the issue is not with the fuel. You said you have spark but where? Did you take out any of the spark plugs to check for spark or did you just hold one of the wires near ground, and did you check multiple wires? Also, is the spark bright blue or just orange or yellow. If it's not blue, then the spark is weak. Finally, if you do have a strong blue spark at the tip of the spark plugs then you're left with investigating a possible low cylinder compression issue.

 

im beginning to see alot of these symptoms come up. most of which i experienced with my dodge 3500. long story short you should try replacing the ignition switch module. it is the black box under your key tumbler where your key goes in. the black box has a plug in with 5 or 6 wires, you might have to take the steering column plastic apart to find it. once you find it there are some torx head screws holding it in. simply remove those screws as well as the key tumbler itself and replace it. come back and let us know if that was your issue. important to know- you will need to learn how to take your old tumbler out of your old I.S. module, once your new module is installed, re install the OLD key tumbler. this was a bit tricky for me but it is pretty easy once you figure out how it works. there may be a video or thread on how to do this somewhere on internet.

these igniton switch modules can go bad and give all kinds of bizzare symptoms. random engine shut off, crank but no start, false suspecting fuel issues. sometimes will start and run rough, die while driving then start up just fine. will present lack of power symptoms as well( leading you to test compression like i did as well)
..will drive fine then have a seizure while driving (weird hick up dies completely but instantly revives several times a second.)

the beginning of my Ignition switch module failing all started with a rough idle. then it turned into all of these other bizarre symptoms. it is also smart to check your terminal connectons and make sure you have no corrosion or old cracked terminals caused from over tightening.

further on i replaced plugs, wires, cap, rotor, igniton pickup coil - ( this is the thin circular plate under distributor box . it has a 2 wire plug i beleive) also replaced the main pick up coil -( this is the singular black box that has a spark wire leading to the center of your distributor cap) confusing since theyre similar in names but 2 suspected parts. i also replaced alternator, battery and relays. after all of these parts i still had that all of the mysterious symptoms... i found out about the Ingition switch module and that fixed my issue completely and its been running strong since. granted replacing all of these other parts did help everything run smooth once it was truely fixed, plus gave me peace of mind knowing everything was brand new, the core problem from the beginning was a bad ignition switch module. dont learn the way i had to. it was expensive and time consuming.

 

So first off we have a scanner with live data.... I don't know how to read the data. Looked at it earlier today. We are going to go ahead and replace the coil as we've tested spark from coil and multiple wires and (both my son and I did separately) and we did NOT get a blue spark. It was orange. My friend, 40 year mechanic, feels that the coil may have been compromised by coolant when he blew the heater hose. If the coil doesn't work we will test the fuel pressure, but I know that we are getting fuel on the rail and we've tried started it several times with stater fluid to the intake with no luck. I feel it does seem to have some what of a rough idle. My son states it still feels like it lacks power. It won't start in the morning when it's cooler, but after turning it over and gassing it for about 30 seconds in the afternoon he can get it started. It will continue to start right up afterwards. The longer it sits, the less likely it is to start however. Turning the ignition into auxiliary multiple times before attempting to start it has no effect.

I visually inspected cap and button and they look brand new. However the distributor ignition pick up looks rather dated. I've heard of ignition switch module causing starting issues. I'm unsure if it would be temperature temperamental however as this seems to be less likely to start when cold. Thank you all for your advice!

 

Take a look at what the PCM thinks engine temp is, when the engine is stone cold, it should be very close to ambient temp.

 

did you replace the ignition switch module? its more than likely going out on you. it will still send spark but be very weak. sounds like youd be better off just replacing all new parts thru out the whole ignition system. from module to main pick up coil.

 

Ok, we replaced the bad O2 sensor and the coil. We definitely have better spark but the problem continues. We've ordered a fuel pressure gauge which should be in by next weekend. It seems to be very temperature temperamental with it being much easier to start when it's warmer. After sitting for four hours it will start, but if it sits over night it won't and yet it starts up after 30 seconds of cranking and gas that afternoon. Still no codes. I'm not totally against the ignition module replacement but I am unsure why temp would effect the module. I am wondering if it couldn't be a fuel valve issue? It's not holding the pressure over night maybe and we are having to re-pressurize to the injectors similar to it running out of gas after it sits for a while? Warm temps expand gas fumes right? I'm pretty sure the couple times we've tested the fuel pressure on the rail it was after repeatedly attempting to start it so that might explain why I had fuel when testing with the engine off and then when cranked. I considered crank and cam sensors as well but I'm going to assume they would probably throw codes. Praying it's not a fuel pump issue because I really don't want to drop the tank on this vehicle or cut through the floor board to access it.

 

Pump will prime as soon as you turn the key to on, What it may be is not getting up to pressure. Try turning the key on then off 3 times then start it. Wait a second before turning the key back to on. This should get the pressure up to where it's supposed to be.

 

Try this...use a hairdryer and warm up the PCM, it's the big silver box over the engine with the 3 large plugs in it. If the engine starts right up after warming up the PCM then it's a bad PCM.

 

^^^^^^^^^^^^^^^^^^^^^^^^fully agree^^^^^^^^^^^^^^^^^^^^^^^