LS1 Losing fuel pressure when engine is hot, cold start works fine
03-25-2016, 04:55 PM
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LS1 Losing fuel pressure when engine is hot, cold start works fine I've been going crazy trying to fix this issue.
I have a 2000 Camaro z28 with ls1.
In the morning when my car has been sitting all night, it starts right up and a very strong start up.
After the engine warms up, when i turn it off, if I try and start it anytime after about a minute, it loses fuel pressure and just cranks. If I crank it for a couple seconds then stop, and crank it again it will start up.
Also, if I prime the key a couple of times to make the fuel pump run, it will start right up, so it's definitely a fuel pressure issue.
Here's the thing though, I already replaced the entire fuel pump assembly and the same problem persists. Fuel filter has already been changed too.
I just ordered a fuel pressure regulator to try that which I'm installing tomorrow, but it was replaced when I changed the fuel pump, maybe that one was bad?
Has anyone had this exact issue and fixed it?
Thanks for any help.
I have a 2000 Camaro z28 with ls1.
In the morning when my car has been sitting all night, it starts right up and a very strong start up.
After the engine warms up, when i turn it off, if I try and start it anytime after about a minute, it loses fuel pressure and just cranks. If I crank it for a couple seconds then stop, and crank it again it will start up.
Also, if I prime the key a couple of times to make the fuel pump run, it will start right up, so it's definitely a fuel pressure issue.
Here's the thing though, I already replaced the entire fuel pump assembly and the same problem persists. Fuel filter has already been changed too.
I just ordered a fuel pressure regulator to try that which I'm installing tomorrow, but it was replaced when I changed the fuel pump, maybe that one was bad?
Has anyone had this exact issue and fixed it?
Thanks for any help.
03-26-2016, 03:23 PM
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Update.
Fuel pressure regulator in the fuel pump seemed to be fine. Could this be something to do with the Evap system as it only happens when the engine is hot?
Help would be greatly appreciated.
Fuel pressure regulator in the fuel pump seemed to be fine. Could this be something to do with the Evap system as it only happens when the engine is hot?
Help would be greatly appreciated.
03-27-2016, 01:15 PM
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I'm more inclined to think IAT heat soak is your problem.
Makes the PCM pull timing and pull fuel (low air mass calc)
neither of which helps starting. Do an experiment - next
time under problem conditions, open the hood and pull the
IAT out of the lid and air-cool it for a minute (blow on it
or use shop air), and try again.
Makes the PCM pull timing and pull fuel (low air mass calc)
neither of which helps starting. Do an experiment - next
time under problem conditions, open the hood and pull the
IAT out of the lid and air-cool it for a minute (blow on it
or use shop air), and try again.
03-31-2016, 06:17 AM
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I'm more inclined to think IAT heat soak is your problem.
Makes the PCM pull timing and pull fuel (low air mass calc)
neither of which helps starting. Do an experiment - next
time under problem conditions, open the hood and pull the
IAT out of the lid and air-cool it for a minute (blow on it
or use shop air), and try again.
Makes the PCM pull timing and pull fuel (low air mass calc)
neither of which helps starting. Do an experiment - next
time under problem conditions, open the hood and pull the
IAT out of the lid and air-cool it for a minute (blow on it
or use shop air), and try again.
