Engine cranks but will not start (Already replaced fuel pump & crank sensor)

I'm having a frustrating no start/intermittent no start/cold start situation. I have searched the forums, and cannot pinpoint the problem.
I have an 05 ZHP sedan. 115,000 miles. Engine cranks but intermittently does not start. As temps get near or below freezing the car seems less likely to start (not sure if this is a coincidence or not).

Just put in new fuel pump, fuel filter and fuel pump relay after having to tow the car to my indy mechanic after being stranded.

It started up for a day or 2, and then would not start. Had to tow it back to my indy. They just installed a new crank sensor. It started while inside the heated shop, but after parking the car outside in the cold it took 3 attempts to start.

Fuel pressure appears fine.

No Check Engine light and no codes are being thrown.

When it starts, it runs and drives normal.

We will check compression next. I am able to repeatedly attempt to start the car. It cranks and cranks, but more often than not just will not start.

Any Ideas? I'm kind of at a loss as to what the culprit could be at this point.

I'd rule out compression; if it runs fine.

It's a long shot, but have you tried adding some HEET/dry gas to the tank to see if that's part of the problem? Failing that, sounds like you have an intermittent electrical problem.

Maybe the injector relay is bad?

Good suggestion - We did put some HEET in the gas tank earlier on in the diagnosis process. Unfortunately it didn't cure the intermittent no starts. I will look into the injector relay also - tks. Due to the increased propensity for a no start when temps are at or below freezing, I wonder if there could be a metal contact or connection expanding/contracting to the point where a necessary circuit fails ???


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this sounds like exactly what my car is doing, however I do have 2 rich codes being thrown. Keep us updated if you get the problem narrowed down

Does it ever not crank?

It sounds like you have pretty much confirmed you have fuel. And it's cranking, and I think we can safely assume you have air. So all that's left really would be spark...? Have you checked the plugs and ignition coils? Not sure how much sense that makes if it's sometimes running...

I would usually assume electrical problems, but if it's cranking I'm not so sure.

I stopped by the shop where the car is. The plugs were checked (pretty darn black on the ends). We replaced with new. When the car is inside in their heated garage it seems to start up fine. When it goes outside to sub freezing temps, it usually just cranks but does not start.

I asked them about the battery being a possibility. Hadn't really considered this as a possible culprit as the car cranks repeatedly with no issue even at 5-10 degrees and it is only 2 years old. Bosch battery tester showed voltage and CCA readings below spec.

Could a bad battery potentially cause this crank but no start scenario?


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Yes, bad battery can cause all kinds of havoc on these cars.

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Quote:

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Originally Posted by nozhp4u

I stopped by the shop where the car is. The plugs were checked (pretty darn black on the ends). We replaced with new. When the car is inside in their heated garage it seems to start up fine. When it goes outside to sub freezing temps, it usually just cranks but does not start.

I asked them about the battery being a possibility. Hadn't really considered this as a possible culprit as the car cranks repeatedly with no issue even at 5-10 degrees and it is only 2 years old. Bosch battery tester showed voltage and CCA readings below spec.

Could a bad battery potentially cause this crank but no start scenario?


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Yes replace the battery and plugs. I just did that to mine and seems to start easier and was having same problem. Granted, my car has not been directly outside but has been in an unheated garage for the past few days.

I bet it's the CCV that blackened my plugs. I should probably refresh the CCV system as I live in a cold climate area. Noticed the telltale "yellow snot," or "mayo" on the oil cap on occasion in the winter if the car hasn't had the opportunity to get temps fully up for extended periods. Even so, I don't think that could be a root cause for a no-start condition. Sounds like you guys agree a weak battery could potentially cause cold temp no-starts.


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