Fuel pump pressure at snap throttle

MIKERF

MEMBER
2007 NISSAN FRONTIER
4.0L
6 CYL
2WD
MANUAL
205,000 MILES

Fuel trims are about +9 combined at idle, and + 7 at cruise. Idle fuel pump pressure 43 PSI, but drops to about 35 at snap throttle, is this, okay?

Monday, May 16th, 2022 AT 10:30 AM

3 Replies

SQM

MECHANIC
6,383 POSTS

Hello,

With the engine idling the fuel pressure should be at 51 PSI.
So being at 35 PSI, it is lower than it should be.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

What kind of issues are you facing?

I have attached the fuel pressure test procedure below for your reference.

Let me know of any questions.

Thank you.

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Monday, May 16th, 2022 AT 4:20 PM

MIKERF

MEMBER
1 POST

I was just concerned because the fuel trims seemed like they were starting to get high. The only issue that I may have (or may just be normal since I live in phoenix) is it sometimes seems to ping when accelerating and it's got, but it has done that for years.

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Tuesday, May 17th, 2022 AT 9:50 AM

SQM

MECHANIC
6,383 POSTS

Engine pinging/knock can happen for early combustion due to carbon buildup inside the combustion chamber. It can also happen if the engine gets too hot. Other reason would be using of poor quality fuel.

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Wednesday, May 18th, 2022 AT 2:37 PM