Jump to content
SAU Community

Fuel Pump Pressure help

rmahnovetsky

By rmahnovetsky,
in General Maintenance

 Share

Recommended Posts

rmahnovetsky Proficient

rmahnovetsky

Posted
Posted

I have been having idling troubles with my skyline R33 and Im trying to diagnose the problem. The main time I notice the problem is

1) When I put fuel in the car.

2) after the car is warmed up then I switch it off then I come back ~15 mins later and start it up.

I have cleaned all the contacts, sensors, AAC, AFM etc.. After doing all that I was begining to believe it was the fuel injectors so I got them cleaned. Still the same problem as the fuel injectors were 95% clean. So I got a inline fuel pressure guage and tested the fuel pressure. What I noticed is when I prime the fuel it goes up to 41 PSI once prime is finished it slowly drops back to 20 PSI. When the car is running it is aroud 36 PSI on idle it is about 34 PSI

Q1) After prime should the psi drop back to 20PSI or should it maintain ~ 41 PSI.

Q2) Is my PSI low?

Q2) any other suggestions.

Link to comment
https://www.sau.com.au/forums/topic/52548-fuel-pump-pressure-help/
Share on other sites
gtrken Grand Master

gtrken

Posted
Posted

Factory pressure should be running at idle of around 38psi.

It shouldn't redally bleed off and this suggests a fuel line leak or a dead fuel regulator.

Try blocking the return line off with a pair of pliers while idling and the pressure should skyrocket and stay there, around 60-80 psi on a stock pump. If it bleeds back quickly then your pump is tired or dead.

There are better tests for this but it involves fuel flow meters which I doubt you would have in your shed :rolleyes:

Cheers

ken

rmahnovetsky Proficient

rmahnovetsky

Posted
  • Author
Posted

test%20fuel%20pressure.JPG

idle%20pressure.JPG

pressure%20at%201000rpm.JPG

Well here are the results.

Clamping at clamp point the pressure rose up to ~60 and then fell back to 50 really quickly. So does this mean the pump is tired?

I noticed taking the lead off in the picture the pressure increased to 41.5 psi and idled well until warm then I had to put it back on for good idle. Though it was idling well with the lead on anyway. Actually adjusting the AAC value I notice the pressure increased/decreased so I guess the AAC value adjusts the pressure to the injectors... Cool!!

The second picture shows idle pressure ~750rpm

The third picture shows idle pressure at 1000rpm.

So does this mean my fuel pump is OK or tired? Am I ever going to solve this idle problem it driving me nuts.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • The Bogan
      NC MX5

      By The Bogan · Posted

      Maine Coone, did look at but to big and fluffy As for performance dogs, we had Mals at work, performance dogs are fun to watch, but, way to much work for this old rooster
    • sonicii
      Who has a Infiniti Q60, Q50 (V37)?

      By sonicii · Posted

      Yep, it was only an option on the Q50 Hybrid.  Same in Japan as far as I know. And doesn't use a centre diff like the Suby's do, so not the same as the WRX.  But it also isn't a reactive AWD like other Nissan AWD vehicles are, eg. Murano/Xtrail/etc.
    • MBS206
      NC MX5

      By MBS206 · Posted

      You should have got a Maine Coone then. Only thing is they're big. But so cool, and just like a dog. Or, just get yourself a high performance dog. That'll teach you for wanting Parkour indoors 😛
    • MBS206
      UniClutch

      By MBS206 · Posted

      Are you thinking of Bens R32? I don't remember if his went through the bonnet itself, but it went through the chassis rail. Brad (RISKIN) bought it, and turned it into a track car. It's funny how anti people are of Jim Berry now. I remember when I pulled mine out (during an engine change) and inspected it and found it cracking badly. At that point in time so many people were even on SAU, were so pro Jim Berry, and that was after Bens GTR exploded his quite publically.
    • The Bogan
      NC MX5

      By The Bogan · Posted

      That's one of the reasons I got that breed, they look weird, the other reasons are they small, they are very vocal, and run around like they are on crack, I didn't want a breed that just sits around, these two are like kids on red cordial  My daughter has one, and it's a laugh riot, constantly doing Parkour around the house, sits on her shoulder, plays catch, and constantly runs around the house taking turns chasing the dog around, her Bermese though, just lays around with constant bitch face, and just looks on in utter disgust at the cat and dog playing together 
×
×
  • Create New...