Fuel pump pulsator
Thread Starter
Teching In
Joined: Sep 2015
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Fuel pump pulsator Hello,
I've had a 98 z 28 for about 10 years and 45k miles, has been a hard starter since I've owned it, usually takes 2 key turns to start. Checked fuel pressure when I first bought it, 58+psi, did a full tune up, and replaced the fuel filter twice. Car runs fine when running.
Today I turned the key and herd a thunk type sound from the engine bay, during the typical double crank, sounded like it was from the drivers side fuel rail. Never noticed the sound before.
I'm wondering if the sound was from the fuel pulsator? Anyone have any experience with this part (part # 12555909) and exactly what it does?
Thanks
I've had a 98 z 28 for about 10 years and 45k miles, has been a hard starter since I've owned it, usually takes 2 key turns to start. Checked fuel pressure when I first bought it, 58+psi, did a full tune up, and replaced the fuel filter twice. Car runs fine when running.
Today I turned the key and herd a thunk type sound from the engine bay, during the typical double crank, sounded like it was from the drivers side fuel rail. Never noticed the sound before.
I'm wondering if the sound was from the fuel pulsator? Anyone have any experience with this part (part # 12555909) and exactly what it does?
Thanks
Thread Starter
Teching In
Joined: Sep 2015
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TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
Ah got it now! Actually a pulse dampener. I doubt that would cause a hard start as all it does is smooth fuel pulses and fuel system noise caused by injection pressure jumps. I don't think they are used anymore on newer stuff.
Thread Starter
Teching In
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thanks for the quick reply, do you think that the thunk I herd that sounded like it was from the drivers side fuel rail could be it?
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
I don't think so. The dampener is a spring loaded diaphragm or something like it to smooth fuel pulses.. The only thing I can think of is it stuck somehow then came unstuck, though a diaphragm would not do that. If it is a piston design it could though
