Slow starting 5.7 issues.
04-13-2013, 08:57 AM
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Slow starting 5.7 issues. My car now takes a while to start, you have to crank on the key a few times. I have a 99 Trans AM with 5.7. It used to fire right off with one turn of the key. Now I have to crank two or three times. Any ideas?
04-13-2013, 11:06 AM
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Dirty injector tips?
Fuel pump check valve failed (not holding fuel in the lines)?
Fuel pressure low?
Old/fouled spark plugs?
Bad tank of gas?
Fuel pump check valve failed (not holding fuel in the lines)?
Fuel pressure low?
Old/fouled spark plugs?
Bad tank of gas?
04-15-2013, 02:44 PM
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We have to turn key on, let off, then turn back on again. I am thinking it may be the fuel pump check valve or fuel pump pressure. After it starts, it runs great. How much of a pain is getting to the fuel pump?
04-15-2013, 08:25 PM
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It's most likely the check valve. It's a project changing the fuel pump. You must drop the rear end (remove sway bar ends, struts), exhaust, and the fuel tank.
When you change the pump, make sure the check valve works in the new one by bolting the whole thing together, but dont bolt the tank into the car yet. I had a brand new fuel pump come to me with a faulty check valve...
The best way to make sure the fuel pump check valve is bad, you need to purchase a fuel pressure gauge, and tap into the shrader valve on the engine. When you turn the key forward, you should build pressure and hold it. For instance if it's 65psi KOEO, it should remain at 65. If it drops in pressure rapidly without starting the engine you know it's bad.
When you change the pump, make sure the check valve works in the new one by bolting the whole thing together, but dont bolt the tank into the car yet. I had a brand new fuel pump come to me with a faulty check valve...
The best way to make sure the fuel pump check valve is bad, you need to purchase a fuel pressure gauge, and tap into the shrader valve on the engine. When you turn the key forward, you should build pressure and hold it. For instance if it's 65psi KOEO, it should remain at 65. If it drops in pressure rapidly without starting the engine you know it's bad.
