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99 STS not starting all the time.


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I have a 99 STS. The car starts when it wants. It will turn over but doesn't start. A shop stated that it’s not getting any fire and told me that it is the ignition module, changed that the problem persists. Then I was told it’s the crank sensors, changed them and the problem persists. I have had the codes checked but there aren’t any. If the car sits for a while, let’s say over night and try to start it and it cranks right up like nothings wrong. It will not cut off while running. Can anyone please help? :huh:

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....I have had the codes checked but there aren’t any.

Next time it fails to start, check the codes yourself. Here's how;


You will be most interested in "P" codes.

It would be worth knowing your actual fuel pressure reading at the fuel rail whenever the engine fails to start. This would require you to buy a fuel pressure gauge.

Sounds to me like whoever is working on your car is not really heavy into diagnostics! Much more into "throwing parts at it". Or "guessing".

At your expense.


Drive your car.

Use your cell phone.


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Hey guy's. The CKP replacement actually resolved the issue. The problem was that the computer was never reset after it was replaced. Once it was reset the car stated every time. The problem now is that once the car is warm and at idol, it will stall. You can drive it and once you stop it stalls out. The only code that the car registers is P1599 “Engine Stall or near stall Detected. I looked the problem up and found that a guy was having the exact same problem after replacing the CKP. What he found out was that one on the sensors had 2 O rings. The old one was stuck to the block, which also caused a few other problems I was having right before the CKP went bad. After removing the O ring, the car ran great. I’m going to check that this weekend and let you guys know the results.

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