Hi all,

So here is what's been going on. My car began to stop starting after it's been driven to temp and parked for 10-20 minutes, then it would eventually start. Finally it threw a crank position sensor code so I put in a new one and the light went out but the problem continued. Well it was due for a time up so new coils, wires, copper core plugs and fuel filter. Car runs awesome but still, same problem. Did some research and found that the coolant temp sensor could be at fault. I replaced that, the thermostat and both oxygen sensors because I figured, why not, they're cheap and easy to install. Temp gauge goes just slightly warmer than before but I always felt it seemed to read cooler than it should (on or below the 1/4 line. Came home from work today after replacing these parts yesterday and boom! Guess what? It's at a warm temp and won't start until the engine coils. My next step maybe? Fuel pump getting weak? Plugs were gapped perfect to spec, etc... Problem persists. Any suggestions before I go dropping my tank go a pump swap? Maybe air pump? I'm at a loss and thought I had it figured out but, nope. Please help me.

 

Also, just to add... fuel pump kicks on, injectors are clean as a whistle and so is the maf sensor. If this rules anything out. Thanks again everyone.

Ken

 

Where did you buy the CPS and ECTS from?
Please don't say Autozone

 

Rock auto. Delphi ects and AC Delco cps.

 

Just tried gas cap... possible vaporlock... no dice. No check engine light. Scratching my head. Just threw in some techron and see if it helps.

 

Ok. That's a relief.

What condition is the CKP (Crank Position Sensor) pigtail in?

I've only ever heard 10 people with S cars ever report the PCM actually threw the CKP code when they had a misbehaving intermittent CKP issue. Congratulations!
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If PCM detects fubar'd or missing CKP signal, no spark and no injector pulse. Since you're at home with your tools, pull a plug (gently, hot aluminum head) and ground the outer electrode to the block. Spark = CPS NOT the issue, no spark = CKP IS most likely the issue (or the associated wiring). Reading resistance of CKP while hot will usually come back open circuit (inf resistance)


Same question for ECTS pigtail. Any corrosion or coolant muck from previously failed sensors can and will have the PCM sensing a Mega high resistance, meaning -40 C, when in fact it should be about 200 or 300 ohms at operating temp.
Inspect the wiring of the connector very carefully. Rube had an ects pigtail fail where the wire actually separated from one of the pin sockets, leaving it open circuit, -40 C etc

 

I did look at them but I will definitely take a second look. The contact points I made sure were clean the cps code went out and has not come back on. Been about 2 weeks since replacement and cps code. I'll have to look more closely at the ects wiring. Such a thin gauge wire... Like a single strand of hair... Well maybe not that bad. One of my friends has had a few S cars and had 2 other ecu that came off of running cars so I'm ALMOST willing to bet ects wiring. Thank you derf. I will post back after double checking the pigtail. I might just run a new one to be thorough. Just shy of 200k! I'm hoping to go another 100k, I really like that little SC and don't plan on parting ways with it.

 

Yep, that pissy little squeeze connector on mine just about drove me nuts. It may have, IDK. But, after replacing that pigtail assembly along with the new ECTS, I had no more engine problems. That crappy TAAT 4 transmission was another issue!

 

It's such a cheesy piece of junk connector. I had the same issue today but I drove through a quarter tank of gas and now it's starting at any temperature. Maybe my injectors aren't as clean as I thought. Maybe the techron worked... We'll see over the next couple days. Supposed to get 3" of rain tomorrow and Monday and I only have a parking lot to work on the car so I won't be tackling the pigtail in the next few days if the problem persists. I'll update you when I get it resolved. Thanks everyone.

 

Well, it' been 3 days since I last checked in. After 2 days of downpours and getting out of work late today... Happy Halloween, I haven't been able to figure deeper into the issue (maybe). It's now starting at all temperature without any hesitation. Fires right up every time. I'm thinking my fuel system is dirty. I just don't know. Never got an idiot light and it' running like a new car. Any suggestions on what I should do to see if a dirty fuel system was the culprit? Why would it only do this when the engine was hot? I'm stumped. Any ideas?