Mechanics

WHY DOES MY HAS A LONG CRANK TIME ONLY DURING WARM MONTHS?

1999 Pontiac Sunfire • 137,000 miles

Why does my 1999 Pontiac Sunfire has a long crank time ONLY during warm months? During Spring/Summer when it gets to be about 70 degrees or over, it has a long crank issue and I have to hold the key down for like 10 seconds before it starts. It usually ONLY does that when I start it for the first time for the day, then anytime after that, it starts like normal until it sits overnight or for a long period of time. BUT, when it is cold in Fall/Winter, it starts perfectly with no problem. It has been this way since I bought the car. It is a 1999 Pontiac Sunfire with a 2.2 OHV At. I have done a full tune up and replaced multiple parts that include fuel pump, pressure regulator, air intake temp sensor, coolant temp sensor, crank sensor, and cleaned injectors and intake manifold. Mechanics can't figure it out and I am about to replace the timing chain, o2 sensors and tps as money permits. I do not get any dtc when I use a code scanner. I am not a mechanic but know enough to diagnose and fix my own car I am just getting no where with this so any help or ideas would be greatly appreciated. Also the car runs great and idles great but once in a while it does idle a little funny for a few seconds but rare. Thanks in advance!
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Silvano
October 25, 2011.




Check the fuel pressure if its within specs and the coolant temperature sensor

Tiny
Rasmataz
Oct 26, 2011.
After replacing the fuel pump and regulator the fuel pressure is up to spec and I put a new coolant sensor and pigtail. Any other ideas?

Tiny
Silvano
Oct 26, 2011.
What's the fuel pressure with and without the FPR

Tiny
Rasmataz
Oct 26, 2011.
Replace the crank sensor. I had this exact same problem and this fixed it completely. Be extremely careful not to break the old one off though. You'll have to drop the oil pan and reseal it.

Tiny
Matthewwansitler
Sep 23, 2012.
Ok, I was wrong. It started well for a few days but went back to the same thing. I had a ASE GM master tech look at it and he told me that it's one or two of the injectors and they should all be replaced. I haven't done it yet but this guy has done a lot of work to my car and he knows what he's talking about
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Tiny
Matthewwansitler
Oct 22, 2012.

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