Hey what's up guys, I recently started experiencing some sputtering when driving my Z once I hit like 3000 to 4000 rpm. It's a fresh rebuild and runs great until I hit those rpms, I know I need to update my build thread lol. I just hit 600 miles on the rebuild today. I also noticed when I take the gas cap off I get some air pressure thrown at me.
I looked at the write up nico has to replace the fuel pump and the symptoms and it seems like this is what it could be to me. Just wanted to check with the experts!
Some other info to help diagnose, The body of the car is just about to hit 80k which is when they usually go right? I have brand new nismo new style 740 cc injectors, new spark plugs, o2 sensors, as EPROM chip.
Thanks in advance Pete
Bad fuel pump?
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Oh Em Zee
- Posts: 549
- Joined: Fri Apr 17, 2009 6:55 pm
- Car: '96 Nissan Z32 Slicktop
'90 Nissan Z32 2+2 - Location: San Jose, CA
Re: Bad fuel pump?
Fuel pumps start to go typically after 160k+.
You'll hear a loud whine when you turn the key to "on" before starting the car. When it is very loud, it's typically on its way out.
We had issues boosting at ~20psi when the fuel pump couldn't keep up with delivery. At 3-4k only? I would suspect something else.
It's always good though to replace the fuel filter every now and then.
You can always install a temporary fuel pressure gauge under the hood to see how delivery is keeping up.
Fuel Pressure Regulator:
vac connected: fuel pres 36.3psi
vac disconnected: fuel pres 43.4psi
80k is pretty early. Typically bushings, belts and hoses need replacement just due to age.
You'll hear a loud whine when you turn the key to "on" before starting the car. When it is very loud, it's typically on its way out.
We had issues boosting at ~20psi when the fuel pump couldn't keep up with delivery. At 3-4k only? I would suspect something else.
It's always good though to replace the fuel filter every now and then.
You can always install a temporary fuel pressure gauge under the hood to see how delivery is keeping up.
Fuel Pressure Regulator:
vac connected: fuel pres 36.3psi
vac disconnected: fuel pres 43.4psi
80k is pretty early. Typically bushings, belts and hoses need replacement just due to age.
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Rager
- Posts: 758
- Joined: Mon May 24, 2010 12:32 pm
- Car: 1992 Nissan 300ZX 2+2
1999 Nissan Sentra
2004 Chevy Silverado - Location: 860, the Z, 802, oh ive got area codes
Re: Bad fuel pump?
id look into the fuel pressure regulator (fpr) not sure if rpm would would make a difference or not. also electrical connections? TPS? MAF? any codes?
thats all i got
gl others should be able to help more than me
thats all i got
gl others should be able to help more than me
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Oh Em Zee
- Posts: 549
- Joined: Fri Apr 17, 2009 6:55 pm
- Car: '96 Nissan Z32 Slicktop
'90 Nissan Z32 2+2 - Location: San Jose, CA
Re: Bad fuel pump?
If you have a bad fuel pump, signs would be sputtering under full boost or inability to start. RPM does play a big role, as that's when the fuel pump works hardest.
I would always check electrical connections. Probably clean the MAF connection of any green corrosion. That can be a PITA at 3k rpm.
I would always check electrical connections. Probably clean the MAF connection of any green corrosion. That can be a PITA at 3k rpm.
Re: Bad fuel pump?
check you ECU wiring harness, i had a bunch of problems with the fuel pump not priming but it was getting power. happened to be the harness wasnt 100% connected.. which the bolt was tight lol. deff check the ecu and make sure EVERY PRONG IS CONNECTED