Jump to content
SAU Community

Recommended Posts

i just finished putting an rb25neo from a stagea into my r32.

i did a rough wiring job just to get the car started

im getting spark, fuel and the injectors are pulsing.

all timing marks on the belt are lined up and the engine has good compression.

but it wont start.

what could be the problem?

timing?

how can i tell if there is any fuel getting to the cylinders?

***im not sure about the compression readings

first three cylinders showed 1.115, 2.110 and 3.105psi. i know this is very low but the car should still start.

i couldnt get any accurate readings for other three cylinders. 4th showed 80psi and 5th showed 60psi.

then i went back to the first cylinder and it showed 60psi?????

im waiting for my battery to charge up. could a bad/flat battery be why im getting these readings?

thanks

Link to comment
https://www.sau.com.au/forums/topic/295414-rb25neo-r32-wont-start/
Share on other sites

Yeh those readings sound really off. I just completed a compression test on my skyline and got 157 across the board (rb25det) which is what yours should be close to.

THe manual for the engine says that the limit is 0.9Mpa on the rb25det which is 130psi and factory is 175psi.

Another problem is that the engine is ment to be warm when performing a compression test.

im not gettting constistent readings.

first test showed 115,110,105, 80 and 60 for the first five cylinders. then i tried again on the first and it only showed 60psi.

this was done on a cold engine.

im pretty sure its not the engine.

how can i tell if the cylinders are getting fuel?

put a fuel pressure gauge on it (makes sure it is at least 40 psi) then put a hose on the injector (other end to your ear) you should hear it clicking, another way is to check with a multimeter.

put a fuel pressure gauge on it (makes sure it is at least 40 psi) then put a hose on the injector (other end to your ear) you should hear it clicking, another way is to check with a multimeter.

i can hear the injectors clicking when i turn the CAS.

does that mean they injecting fuel?

what do i put the fuel pressure guage on?

what would happen if i put a little fuel into the cylinder through the spark plug hole and tried starting it?

if it sounds like its firing then i guess im not getting any fuel to the cylinders.

would this work?

thanks

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


  • Similar Content

  • Latest Posts

    • The wiring diagram for the R33 RB25 is freely available, and is essentially the same same as most other RBs (just with differences as to which pin # does which job). To get the ECU to power up, you just need to provide power to the ECCS relay, and have the other power feeds that come in from the top left of the wiring diagram (wrt the ECU) that give perma power to the fuel pump relay, the ECU itself, etc etc, all connected. When you put power on all these it will just come to life. It's pretty clear from the diagram what needs to happen. Just follow the lines from the 12V + supply stuff in the top left over towards the ECU. I've even posted snips of such diagrams (not for vanilla 25, I think for Neo and 26) to various threads here in the last few months, talking about what it takes to get the fuel pump and FPCM up and going. Search these up and they will help get you started on doing the same with the vanilla 25 diagram. Hell, for all I know, I've done the same with that one in years past and have forgotten.
    • Yep...so unless someone posts up the answer you will need to probe from the ECU connector to the dash plug with a multi meter in continuity mode to trace the wires.  Note the ECU has multiple - and + (and across different key settings - Battery, IGN and Start) and most likely the power is fed from the connector(s) that is normally near the left hand headlight.
    • Thanks Duncan, I am actually just trying to get the Rb turning and running with the RB25DET S2 original loom itself  I am just trying to get it going outside the body and not thinking about the S15 or trying to match anything to the S15 loom at all I am only trying to see if anyone has done this and what pin they found to be the ignition trigger and ECU+/- on the dash connector, that's about it. Thanks  
    • Hi Guys, Does anyone know any aftermarket part numbers for a starter motor to suit the VQ25DET? I can find lots of alternative part number for the VQ35DE, which I assume would fit, but there is a lot of conflicting information out there. Thanks..
    • I don't understand how this hasn't boiled down to - Upgrade the turbo when you have everything required. ECU, injectors, fuel pump, turbo, etc. Do it all at once.  If you don't have everything required, just enjoy the car as it is and keep saving up your pennies. 
×
×
  • Create New...