Don't thank me, Ken. I'm done. You and derf are getting way over this old mans head with this stuff. In all the years I've owned cars, I've NEVER had to replace an 02 sensor. And I've had a LOT of different cars with well over 100,000 miles on them.

 

You are the emotional support...hahaha. No but you make valid suggestions and I appreciate that.

 

Do you always get gas from the same places?

I once had the fuel filter on my Geo Metro clog on a cross country trip a few years ago as a result of getting bad gas at a hole-in-the-wall gas station out West. Had to replace it at night in a Walmart parking lot in Arkansas with a pair of vise grips I borrowed from the people overnighting in a motor-home in that same parking lot. That filter was the last one the Advance Auto (shudder) in that town had and they were the only place that was still open that night (they locked up when I left).

Long story short (too late), only one tank of bad gas can wreak havoc on your fuel system.

 

Not all the time, but I steer clear of the no name gas stations. Usually I fill up at Sunoco, occasionally at Shell and rarely at Exxon/Mobil. All of which are owned by the same franchise in the northeast here. Kind of a monopoly out here between 3 franchise owners with different fuel brands in each franchise. I see the same transport company filling the fuel supplies at two of the franchises and the one I use has their own fuel delivery tanker trucks. Just prefer the one I use because I've never had fuel related problems before and they offer a pretty attractive rewards program.

 

I think it's worth mentioning that I always run 87 octane and have used Techron fuel system cleaner a couple times a year. I've owned the car for a little over two years and I don't know how well the previous owner maintained it. I would guess, not that well based on the fact that I have replaced the fuel filter twice now and the first time the filter that was on the car when I purchased it was probably the worst I have seen. I just performed my second tune up since owning the car and the plugs, wires, etc... That came on it surprised me that the car even ran. Keeping up on oil changes has improved oil clarity upon changing it. I feel like I'm reversing years of neglect. In essence, I have polished a turd and now I have a clean running, nice looking car that I'm proud to feel that I gave it a second life. This is just a bump in the road that I will eventually correct. I will post back after I get positive results. Hopefully tomorrow night as my new cps just came in.

 

*UPDATE * Changed CPS again and the problem persists. BUT! As derf suggested, depress the Schrader valve at the fuel rail to see if I'm getting fuel to that point. I tried this and it's definitely getting fuel to the rail. Fuel does spray when depressed. When it's cranking and not starting, if I purge the Schrader valve the fuel sprays as it should and shazaam, like that, the car fires right up. What gives? No check engine light on start up when I do it this way. If I wait a half hour after crank and no start, the car will eventually fire up (this is when I don't depress the Schrader valve) but it will hard start and throw the po141 and po336. I just can't make sense of it. Anyone ever heard of this? What does it mean? Thank you everyone who is helping me through this mystery.

 

I will guess insufficient fuel pressure.Why?
I drive a 97SC2. They were known to have been built with fuel pumps that mostly failed. When functioning normally, the fuel system in these S cars holds fuel pressure between starts. There's a spec you can test it to (PSI drop at the rail vs time) to determine if yours is bleeding off too much pressure per unit time.

The problem with the 97 fuel pumps was that they bled obscene amounts of fuel pressure when at rest, making starting and restarting difficult.

It took me several YEARS to figure out that there was a "sweet spot" time wise during which I had to crank the engine and have it fire right up regardless of when I was trying to start it.
It took time for the fuel pressure to build back up.

That sweet spot to crank it for me is right after the SERVICE (not service engine soon) goes out on the start up bulb check. Works 99% of the time. IF I wait LONGER, it is not happy, though. I would think the pressure would be trying to get to the upper end of the acceptable pressure range. It may be, but the damn car won't start so I go by the timing of that light.
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Fuel pressure regulator comes to mind but I think they are internal to the fuel filters on the 3rd gen coupes like yours.
The regulator on the 1st n 2nd gen coupes is a discrete one and is after the Scrader valve. But if not functioning properly, it can still lead to problems.
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Do a loan a tool or use a fuel pressure gauge and compare to key on engine off, key on, engine on, and do a pressure bleed off test. I know the ranges are in a Chilton's book I have. Lemme see (groans to get up)

I am assuming you are hearing the 3 second priming going on when key on engine off.

Basically, you relieve the fuel pressure at the test valve with the engine off, then hook up a gauge, THEN start the car (AFTER cleaning up any stray gas =flammable) and look for the following

Fuel System Pressure: 40 to 55 psi AT IDLE (vehicle at operating temp)
Fuel System Pressure DECAY (first 5 min after shutoff) : 8 psi MAX
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98 and up: THe fuel press regulator is integrated into the fuel filter assy.
Also, 98 and up are returnless which means there is no line that returns to the tank. Sometimes the return lines on the older S cars develop obstructions, but I don't think yours has an obstruction because you don't have a return line.
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It may be that you have a small fuel leak in a line or an intermittently leaking injector that is bleeding off pressure and fuel. I suppose you could "flood" 1 cyl if it was an injector sticking open now and then, but I don't think that would take too many engine rotations to be jettisoned into the cat.

Sorry for the train of thought oozing of info -- just how my brain wanders, circling the wagon
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The fact that the techron made the problem temporarily disappear has me leaning in this direction (leaky /dirty injector not closing all the way -- maybe more of an issue when warm. you can try the bleed test when it's not acting up and when it is and see if the rate of pressure bleedoff is the same\
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If your car never had the "magic window of starting" like mine, it prob hasn't grown one
Do not condemn the fuel pump unless it does not meet specs as is by deduction proven to be faulty.



Note I said GUESS.

 

Sounds about right to me. I will be doing as you suggested. Thanks again!

 

The 8 psi is the MAX bleedoff in the 1st 5 min
(sorry bout that)

Remember, if there is an excessive pressure bleedoff, you're only going to catch it when it's acting up, which means after a drive and sitting hot.
I'm thinking now that I am not half asleep that you may just want to slap the pressure gauge with key on, engine off on there without a purge, because iwhen you purge it, you purge away the "caught you red-handed" evidence you need.

But it must be key on engine off.to compare apples to apples.

Then purge and retest, If an injector is leaking or pressure is bleeding off at the pump or somewhere else you should see it,

When I do not get my car started on the 1st or 2nd crank, it seems to easily flood and then I have to hold the pedal down to clear it while it fights, turns over, lets out a nasty plume of exhaust, then smooths out,

I run techron from time to time. It greatly improves throttle response but doesn't do a damn thing about starting for me. The fact that it seems to be directly related to the presence or absence of the symptoms for you points me towards the injectors.

The part of this I fail to yet understand is why it continues to throw a CKP code unless there is an intermittent wiring issue, either at the connector or possibly at the other end where the signal goes into the PCM.
Have you been able to park the car and read the codes for a pending CKP code BEFORE trying to restart it?
Check for this, as it will help us differrentiate between whether the CKP trouble is occurring BEFORE an attwmpted HOT restart or AFTER and attempted HOT restart. THere are of course other issues that cause CKP codes but don't wanna go there. If the car is running, it can't be that serious. I'm guessing electrical contact a the pigtail or PCM is involved

"This is only a Guess."
---Violent Femmes

 

No. As soon as I shut the car off the codes go away. Yesterday I changed the oil and got a better look at the cps pigtail, unplugged it and the rubber boot that houses the male end of the pigtail just fell apart. Luckily I had another one and when I plugged it back in, it was much more snug. The pigtail itself is getting the proper ohms, so I'm hoping that was the fix for that portion of the problem. With the old boot, the connection was very loose. I can only hope. It hasn't thrown a code since but it's barely been a day. As for the crank no start, it only does it when the engine is warm. If I let the car sit for about 1/2 hour, it'll fire right up. That is unless I purge the Schrader valve at the fuel rail. If I do that when I get crank no start, it'll fire right up. Might just replace the injectors if they're cheap enough. In the meantime there's a couple small fixes I'm going to tackle.