Engine Starts, runs 10 second and dies
03-20-2008, 05:37 PM
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Engine Starts, runs 10 second and dies Hi,
I'm pretty new here and have searched without the answer to my question. I installed an 1995 LT1 Corvette motor into an older pickup. I had a custom harness made. I'm using the starting circuit from the pickup not the car. ECM has VATS removed...both the normal VATS and Corvette VATS. Here is my problem. Motor will start and run fine for 5-10 seconds and then die. When it dies, there is no stumbling, missing etc...it just dies like somebody shut off the key. It will immediatly start up again and do the same thing. I can rev the motor and all is fine up until the 5-10 second window and then it just dies. I have checked fuel pressure.....40-45psi at startup and running. No service engine light is on. If I spray a mist of fuel into the intake, I can keep the motor running, but when I quit spraying the mist, it dies. This still seems like a VATS issue to me, but I'm not sure. Any help would be appreciated.
Shane
I'm pretty new here and have searched without the answer to my question. I installed an 1995 LT1 Corvette motor into an older pickup. I had a custom harness made. I'm using the starting circuit from the pickup not the car. ECM has VATS removed...both the normal VATS and Corvette VATS. Here is my problem. Motor will start and run fine for 5-10 seconds and then die. When it dies, there is no stumbling, missing etc...it just dies like somebody shut off the key. It will immediatly start up again and do the same thing. I can rev the motor and all is fine up until the 5-10 second window and then it just dies. I have checked fuel pressure.....40-45psi at startup and running. No service engine light is on. If I spray a mist of fuel into the intake, I can keep the motor running, but when I quit spraying the mist, it dies. This still seems like a VATS issue to me, but I'm not sure. Any help would be appreciated.
Shane
03-20-2008, 06:48 PM
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Just a guess, but have you check fuel pressure at the rail? It may build pressure when it primes when you turn the key, but not continue to pump fule, hence the motor dying... I would check that first, also check the fuel filter, it may be clogged...
G.L.,
Bill
G.L.,
Bill
03-20-2008, 07:06 PM
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Oil pressure switch?
I believe one of the oil presure switches on my 95 vette kills the engine if the oil pressure doesn't get high enough soon enough.
Reading the fuel system from the tech manual I was wrong
The oil pressure switch energizes th fuel pump as soon as oil pressure hits 4psi but it is a back up for the fuel pump relay soo something else must be going on.
When every thing is working correctly
Turning ignition switch to the ON position before engaging the starter. The PCM engerizes the fuel pump relay for two seconds, causing the fuel pump to pressurize the fuel system.
****If the PCM does not receive ignition reference pulse (engine cranking or running ) within 2 seconds it shuts off the fuel pump relay causing the fuel pump to stop.
VATS (PASS Key) usually has a 3 minute time out and if you try to crank prior to the 3 minute time out it should reset the timeout and you have to wait 3 more minutes (even if you pull the battery)
So I believe it may be related to fuel pump relay or ignition reference, fuel pressure regulator. Is it throwing codes?
MIke
I believe one of the oil presure switches on my 95 vette kills the engine if the oil pressure doesn't get high enough soon enough.
Reading the fuel system from the tech manual I was wrong
The oil pressure switch energizes th fuel pump as soon as oil pressure hits 4psi but it is a back up for the fuel pump relay soo something else must be going on.
When every thing is working correctly
Turning ignition switch to the ON position before engaging the starter. The PCM engerizes the fuel pump relay for two seconds, causing the fuel pump to pressurize the fuel system.
****If the PCM does not receive ignition reference pulse (engine cranking or running ) within 2 seconds it shuts off the fuel pump relay causing the fuel pump to stop.
VATS (PASS Key) usually has a 3 minute time out and if you try to crank prior to the 3 minute time out it should reset the timeout and you have to wait 3 more minutes (even if you pull the battery)
So I believe it may be related to fuel pump relay or ignition reference, fuel pressure regulator. Is it throwing codes?
MIke
Last edited by aboatguy; 03-20-2008 at 07:36 PM.
