Intermitten starting Problems
Thread Starter
Teching In
Joined: Jun 2008
Posts: 42
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From: Alexandria, VA
Intermitten starting Problems Today my 01 SS had problems starting when sitting for a while. It starts up fine when its warm and runs great.
The engine turns over really well so its not the battery or the starter.
I checked the fuel pressure while running and its close to 60 psi. Also checked the pressure after it cooled off and didn't want to start and as the engine is turning over the pressure goes up to 50 psi and I can hear the fuel pump prime when I turn the ignition on.
I can't imagine it being the clutch activation or neutral activation switch since the engine does turn over.
I didn't notice the alarm light but I'll go out again and check.
Anyone have experience with this or any ideas? I'm taking a road trip on Sun and this is not good.
Any help is appreciated.
The engine turns over really well so its not the battery or the starter.
I checked the fuel pressure while running and its close to 60 psi. Also checked the pressure after it cooled off and didn't want to start and as the engine is turning over the pressure goes up to 50 psi and I can hear the fuel pump prime when I turn the ignition on.
I can't imagine it being the clutch activation or neutral activation switch since the engine does turn over.
I didn't notice the alarm light but I'll go out again and check.
Anyone have experience with this or any ideas? I'm taking a road trip on Sun and this is not good.
Any help is appreciated.
Thread Starter
Teching In
Joined: Jun 2008
Posts: 42
Likes: 0
From: Alexandria, VA
Thanks for the feedback. Will a failing Crank position sensor cause the Service Engine light to come on?
Would the 50psi be the cause of it not starting? I was doing a search and found someone that stated that the psi for the fuel needed to be between 55-60.
I had also noticed that the car when cold would stall at higher RPM's for a split second.
Again thanks for replying.
Would the 50psi be the cause of it not starting? I was doing a search and found someone that stated that the psi for the fuel needed to be between 55-60.
I had also noticed that the car when cold would stall at higher RPM's for a split second.
Again thanks for replying.
Just to clarify, when you say you have problems starting after sitting a while, by problems do you mean no crank at all or the car cranks over fine just doesn't start? From the sounds of your post, it cranks over fine but doesn't fire correct?
I also experience the same problem as you (https://ls1tech.com/forums/general-m...ut-cranks.html) and my problem was the relay(s). Try swapping the ignition relay with one of the fan relays to see if that fixes your problem. If you do end up buying new relays I'd suggest to get them from the dealer, the ones I got from autozone were bad and it took me forever to figure that out.
To answer your question on a failing crankshaft position sensor throwing a CEL - I searched for this as well since I didn't know either, there is a code for it but I did read about some people having starting problems w/out having a CEL and it turned out to be the Crankshaft Position Sensor. My reasoning behind it (others feel free to correct me if I'm wrong) but when the CPS works and the car does start and run, there's no reason for it to throw a code, but when the car won't start the computer isn't able to "diagnose" and save the code to show once the vehicle does start.
I'd try the relay first, if it isn't that then maybe the CPS, or check around for bad grounds or shorts in the wiring. At least that's what my game plan was haha. Has anything else happened to the car (mods, repairs, etc) that coincides with the start of the problem? Let us know if any other symptoms arise.
I also experience the same problem as you (https://ls1tech.com/forums/general-m...ut-cranks.html) and my problem was the relay(s). Try swapping the ignition relay with one of the fan relays to see if that fixes your problem. If you do end up buying new relays I'd suggest to get them from the dealer, the ones I got from autozone were bad and it took me forever to figure that out.
To answer your question on a failing crankshaft position sensor throwing a CEL - I searched for this as well since I didn't know either, there is a code for it but I did read about some people having starting problems w/out having a CEL and it turned out to be the Crankshaft Position Sensor. My reasoning behind it (others feel free to correct me if I'm wrong) but when the CPS works and the car does start and run, there's no reason for it to throw a code, but when the car won't start the computer isn't able to "diagnose" and save the code to show once the vehicle does start.
I'd try the relay first, if it isn't that then maybe the CPS, or check around for bad grounds or shorts in the wiring. At least that's what my game plan was haha. Has anything else happened to the car (mods, repairs, etc) that coincides with the start of the problem? Let us know if any other symptoms arise.
Thanks for the feedback. Will a failing Crank position sensor cause the Service Engine light to come on?
Would the 50psi be the cause of it not starting? I was doing a search and found someone that stated that the psi for the fuel needed to be between 55-60.
I had also noticed that the car when cold would stall at higher RPM's for a split second.
Again thanks for replying.
Would the 50psi be the cause of it not starting? I was doing a search and found someone that stated that the psi for the fuel needed to be between 55-60.
I had also noticed that the car when cold would stall at higher RPM's for a split second.
Again thanks for replying.
50psi is plenty for engine start.
.
Thread Starter
Teching In
Joined: Jun 2008
Posts: 42
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From: Alexandria, VA
Gents thanks for the input. Very much apprecated.
To clarify its an intermitten no start but cranks just like you experienced Sandsk8erz400.
LS6427, I got the no start again and measure the fuel pressure again to where I could see it from in the car and with the pump running at prime before starting the pressure went up to 58 and as soon as it stops priming it drops to 50 and holds. While trying to start with the engine turning over the psi for the fuel did go up to 58.
I went ahead and changed out the crank sensor and still haven't had a no start condition yet.
However I think I will prob do what Sandsk8erz400 suggested and change out the ignition relay just to be sure since I'm now in Florida and not home in DC.
Again thank you for posting and if anyone else has experienced similar situations please post as this will show up on seaches and will help others in the future.
To clarify its an intermitten no start but cranks just like you experienced Sandsk8erz400.
LS6427, I got the no start again and measure the fuel pressure again to where I could see it from in the car and with the pump running at prime before starting the pressure went up to 58 and as soon as it stops priming it drops to 50 and holds. While trying to start with the engine turning over the psi for the fuel did go up to 58.
I went ahead and changed out the crank sensor and still haven't had a no start condition yet.
However I think I will prob do what Sandsk8erz400 suggested and change out the ignition relay just to be sure since I'm now in Florida and not home in DC.
Again thank you for posting and if anyone else has experienced similar situations please post as this will show up on seaches and will help others in the future.
Thread Starter
Teching In
Joined: Jun 2008
Posts: 42
Likes: 0
From: Alexandria, VA
While searching for info on the ignition relay ran into this http://www.gearchatter.com/viewtopic8933.php
Shows the wiring diagram for the ignition relay. Now it makes sense why it would cause a no start.
Shows the wiring diagram for the ignition relay. Now it makes sense why it would cause a no start.
