Long hesitation when starting
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 48
Likes: 0
From: Las Vegas NV
Long hesitation when starting
Symptoms since the new motor and blower was installed:
When the car is cold it turns over without hesitation.
If I stop and get gas or leave for 15 minutes it fires right up.
If I leave the car for 1 to 16 hours it takes almost 6-7 full seconds to turn over whether it is 32deg or 110deg outside.
I have had 3 very experienced/reputable tuners tweek the tune and test the suspect components(LPE box, PCM, Tune).
The LPE reluctor wheel converter box is fine and so is the PCM.
The car drives/behaves great from a stop to any speed at any RPM.
Has anyone had similar symptoms? If you did what was the issue?
I am running out of ideas. Thank you in advanced for reading this thread.
Thank you - Dan
Here is my set up.
GM LSX376 with LS3 Heads and intake
LPE Reluctor Wheel Conversion box
Blower Cam
Dynatech Headers
Procharger D1SC @12psi
8 rib Pulley Conversion
Twin Walbro Fuel Pumps
Precision 85lbs injectors
External Oil Cooler
RPS twin carbon lite clutch and alum flywheel
When the car is cold it turns over without hesitation.
If I stop and get gas or leave for 15 minutes it fires right up.
If I leave the car for 1 to 16 hours it takes almost 6-7 full seconds to turn over whether it is 32deg or 110deg outside.
I have had 3 very experienced/reputable tuners tweek the tune and test the suspect components(LPE box, PCM, Tune).
The LPE reluctor wheel converter box is fine and so is the PCM.
The car drives/behaves great from a stop to any speed at any RPM.
Has anyone had similar symptoms? If you did what was the issue?
I am running out of ideas. Thank you in advanced for reading this thread.
Thank you - Dan
Here is my set up.
GM LSX376 with LS3 Heads and intake
LPE Reluctor Wheel Conversion box
Blower Cam
Dynatech Headers
Procharger D1SC @12psi
8 rib Pulley Conversion
Twin Walbro Fuel Pumps
Precision 85lbs injectors
External Oil Cooler
RPS twin carbon lite clutch and alum flywheel
Last edited by danoz; Jun 13, 2013 at 10:03 PM. Reason: Forgot to add my name
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 48
Likes: 0
From: Las Vegas NV
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 48
Likes: 0
From: Las Vegas NV
It's the latter. 67psi of fuel pressure as soon as I turn the key. That was my first guess as well. It was behaving like it wasn't getting any fuel.
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
If it is "cranking" at normal speed, but not starting, your either not getting spark or fuel. Most likely is fuel. There is a check valve in the feed line near the tank that may be allowing the fuel to bleed back to the tank. Since you essentially have a one line system, if it bleeds back you will need to crank it until the air bleeds out of the injectors.
To check it, you can cycle the ignition a few times, then crank it. you can also release the shrader valve and have someone turn the key to the on position. If you get air out of the valve before fuel, it's bleeding back.
Be careful! Don't get fuel in your face or on a hot engine. Have rags handy to soak up what comes out. Let it dry before you crank it.
To check it, you can cycle the ignition a few times, then crank it. you can also release the shrader valve and have someone turn the key to the on position. If you get air out of the valve before fuel, it's bleeding back.
Be careful! Don't get fuel in your face or on a hot engine. Have rags handy to soak up what comes out. Let it dry before you crank it.
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 48
Likes: 0
From: Las Vegas NV
If it is "cranking" at normal speed, but not starting, your either not getting spark or fuel. Most likely is fuel. There is a check valve in the feed line near the tank that may be allowing the fuel to bleed back to the tank. Since you essentially have a one line system, if it bleeds back you will need to crank it until the air bleeds out of the injectors.
To check it, you can cycle the ignition a few times, then crank it. you can also release the shrader valve and have someone turn the key to the on position. If you get air out of the valve before fuel, it's bleeding back.
Be careful! Don't get fuel in your face or on a hot engine. Have rags handy to soak up what comes out. Let it dry before you crank it.
To check it, you can cycle the ignition a few times, then crank it. you can also release the shrader valve and have someone turn the key to the on position. If you get air out of the valve before fuel, it's bleeding back.
Be careful! Don't get fuel in your face or on a hot engine. Have rags handy to soak up what comes out. Let it dry before you crank it.
Last edited by danoz; Jun 17, 2013 at 02:02 AM.
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Racer
Joined: May 2011
Posts: 258
Likes: 0
From: Acworth Georgia
Like Marty said, cycle the ignition a few times. Turn the key to on but not start and let it sit there for about 5 seconds letting the fuel pump build pressure. do this 3-4 times then try to start it. If it starts right up , or starts much sooner then you have a fuel pressure issue.
Good luck
Good luck
Last edited by Bill McCassey; Jun 17, 2013 at 07:35 AM. Reason: spelling
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
For us to help you, you need to stop using the phrase "the car turns over". That phrase has to many interpretations. There are to basic no start conditions. The engine cranks normally but does not start or the engine does not crank. When everything is working, you turn the key to start and the engine begins to crank. Then the fuel injectors deliver fuel and the ignition fires the plugs. Generally after 1-3 seconds the engine comes to life or starts.
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 48
Likes: 0
From: Las Vegas NV
For us to help you, you need to stop using the phrase "the car turns over". That phrase has to many interpretations. There are to basic no start conditions. The engine cranks normally but does not start or the engine does not crank. When everything is working, you turn the key to start and the engine begins to crank. Then the fuel injectors deliver fuel and the ignition fires the plugs. Generally after 1-3 seconds the engine comes to life or starts.
After the engine has been running for any duration of time whether it is 10 seconds or 3 hours it does the following after the engine has been shut off.
Within about the first hour it cranks normally and starts within 1-2 seconds.
Sometime between 1-12 hours if you put the key in the ignition it cranks normally but the engine will not start for about 6-7 full seconds.
Last edited by danoz; Jun 18, 2013 at 12:20 AM.
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 48
Likes: 0
From: Las Vegas NV
Like Marty said, cycle the ignition a few times. Turn the key to on but not start and let it sit there for about 5 seconds letting the fuel pump build pressure. do this 3-4 times then try to start it. If it starts right up , or starts much sooner then you have a fuel pressure issue.
Good luck
Good luck
Melting Slicks
Joined: Aug 2008
Posts: 3,451
Likes: 27
From: Bay Area CA
I had a very, very similar issue...and I thought it was the battery. So I replaced it.....twice. Well - it turned out to be the cam position sensor. My tuner changed the version of the sensor, and it fires right up.
Drifting
Joined: Apr 2009
Posts: 1,898
Likes: 9
From: Morrisville PA
I am having the same issue after my forged 347 swap. Tried every parameter in hptuners, none make a difference.
Car sits, starts like crap. It will crank for 4-5 secs then start up. If you shut it off, and start again, it starts right up.
Interested in the solution!
Car sits, starts like crap. It will crank for 4-5 secs then start up. If you shut it off, and start again, it starts right up.
Interested in the solution!
Thread Starter
Intermediate
Joined: Jul 2007
Posts: 48
Likes: 0
From: Las Vegas NV
I know it has been a while but I have finally found the cause of my problems. I had a twin pump setup in my car with a racetronix wiring kit. So there was a 10g wire that went to a 14g wire that fed two 12gauge wires(pumps). The connectors on both the inside and outside of the tank was damaged from excessive heat. After fixing this and replacing the 14 gauge wire with a 10 gauge wire in the basket the car starts up a lot faster. So in the end it was just a 25 cent part that cause all the issues for me. I am not in any way suggesting you remove your tank and check the connector because it was very expensive, just sharing the solution for my car.