Fuel Pressure Test On R34 Rb25det

[Pawel0409]

does any one knows how to check fuel presure

i have bought a fuel test gauge

just not 100% sure where to conected

should i conected on the hose which goes between fuel filter and fuel regulator

thanks

[Pawel0409]

does any one knows how to check fuel presure

i have bought a fuel test gauge

just not 100% sure where to conected

should i conected on the hose which goes between fuel filter and fuel regulator

thanks

[JonnoHR31]

yes connect it between the filter and the first reg.

[Pawel0409]

why am i getting high fuel press?

58psi

and it doesnt make diffrent if i disconet the vacume hose

[JonnoHR31]

did you disconnect both vac lines? theres 2 regs each with its own vac line

any why start a 2nd thread about the same thing?

[Pawel0409]

which on is the second reg ?

thanks

[QWK32]

the fuel pressure reg is to the right bolted on the end of the rail. the other two from what i understand, are fuel dampers to help smooth out pressure surging and spikes. nissan fast also lists them as dampers.

see attached,

[rondofj]

Josh r u sure that is the reg, I need to check fuel press on mine

[JonnoHR31]

reg is the one on the end of the rail. regardless, if you wanna check fuel pressure put the gauge in the line between the fuel filter and the rail

[simpletool]

I'd imagine that - Before the reg will be pump pressure, which needs to be higher than the set reg pressure. After the reg should be the set reg pressure + boost.

[rondofj]

so what is the stock 'set' reg pressure, I read somewhere that it is 48psi with varying opinions.. So mine should be 48psi + 12psi boost??

[r33cruiser]

The norm seems to be around the 35psi mark at idle. Mine sits at 33-34psi

[DVS JEZ]

so what is the stock 'set' reg pressure, I read somewhere that it is 48psi with varying opinions.. So mine should be 48psi + 12psi boost??

Dont allow for boost predsure when checking at idle. When on 12psi it should rise 12 psi.

[JonnoHR31]

base pressure (0 vacuum/boost) should be 43psi/3bar

[rondofj]

haha jez I will leave it to you to check the blood pressure, fuel pressure or whatever.. Hoping your dyno guy will be available the week after to let us use his workshop

[rondofj]

yesterday i filled up and again it did almost 20L/100kms the second time round, ridiculous economy - I would have expected it to drink less as its running lean in the mid-upper rpm band..

[caaraa]

the fuel pressure reg is to the right bolted on the end of the rail. the other two from what i understand

[JonnoHR31]

yesterday i filled up and again it did almost 20L/100kms the second time round, ridiculous economy - I would have expected it to drink less as its running lean in the mid-upper rpm band..

have you checked the fuel pressure? a dead reg can cause that

[rondofj]

Thats what we will do when we take it to the dyno this sat, stupid car causing me headaches lol..hoping its the reg not pump, how do regs die.??

[JonnoHR31]

either the diaphram stops working properly and it affects pressure or they leak into the vac line and flood the motor.

i somehow managed to kill 3 regs in a matter of weeks and all 3 ran rich under vacuum and leaned right out under boost, fuel pressure just remained constant instead of rising and falling with manifold pressure.

so yer, check pressure and check the vac line for any signs of fuel