Jump to content
SAU Community

Lifter Pump Up Problems Driving Me Mental!

r31et
 Share

Recommended Posts

r31et Explorer

r31et

Posted
Posted

hey all so ive built an rb30de ( will turbo it later but for rwc no turbo cos its in a aus r31) the build consists of.

-r33 rb25det vct head with non vct cams.

-rb20det red top cams.

-standard rb30 bottom end.

-rb25det oil pump.

-series 2 ecu/coil packs and loom.

my first problem was a rattle in the top end at around 3500-4000rpm, and a missfire that would only occur when the motor was cold and the motor was given a little rev it would drop a cylinder and pick it back up when the motor had a bit of heat in it, so i pulled out the lifters and pulled them apart and cleaned and primed them and got rid of the vct cams because thats where the rattle was coming from, fixed that rattle but its now an absolute nighmare to start from cold, what seems to be happening is that the exhaust side lifters are pumping up on cold start and holding the valves open a touch, it starts up perfect but a few seconds after it starts when it gains full oil pressure its dies and when cranking to start it up again it sounds like only half the cylinders have compression. the only way to get it going is and soon as the motor fired bring the revs up to about 3.5k (the combustion pressures must be enough to keep the valves from opening) till it has warmed the oil a bit and then it runs absolutely perfect, no issues whatsoever.

Im starting to run out of ideas as to what could be wrong with the damn thing so if anyone has any ideas id really appreciate it!

r31et Explorer

r31et

Posted
  • Author
Posted

did you use reground cams/new lifters? if you mix n match secondhand parts they will rattle(noisy) for sure

No they are the original lifters for that head and rb20 red top cams, I have no rattles, they exact opposite the lifters do more than taking up the lash between lifters and cams they over do it an start opening valves when they should be shut

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

    • joshuaho96
      R32gtr sputtering and stalling

      By joshuaho96 · Posted

      I'm aware, but unless you're actually seeing the voltage the ECU is seeing and you're able to verify the sensors are actually working I find it hard to just trust STFT/LTFT. I will say, logging the ECU comes naturally to me because it's one of the lowest effort methods of diagnosis and I do similar things in my day job all the time. Staring at 20+ charts looking for something that isn't quite right isn't for everyone. NDS1 allows you to log almost everything so that's normally what I do and then sort out the data later. 
    • MBS206
      Neil's R33 Gts-t Build

      By MBS206 · Posted

      Silly question, as I bet you've checked already, but the motor turns over by hand yes? I suspect Neil has a spare starter, though if not, I believe I have a spare R33 (or two) starter.
    • Duncan
      NPboosted manifold fitting purpose

      By Duncan · Posted

      Yeah just run one of those posts to the Link like GTSBoy said. From google it looks like a "mishimoto boost controller" is a manual boost controller. Since you already have the link just buy any MAC valve and plumb it in where the mishimoto is now. Wires to the solenoid should come from the Link's / standard loom boost control wiring (I guess you have an r32, not sure if it is gtst or gtr, if it is GTR where is a 2 pin connector near the engine bay fuse box/injector resistor for that purpose, assuming the standard boost controller is gone)  
    • GTSBoy
      NPboosted manifold fitting purpose

      By GTSBoy · Posted

      No. The ECU's hose is for a connetcion between the plenum (assuming single throttle body, not ITBs) and the ECU's internal MAP sensor. This is the primary load measurement of the ECU - so you need to get this one right. This has NOTHING to do with the boost contol. The wastegate also needs to see a boost signal - but it is actually far better for it NOT TO COME FROM THE PLENUM (again, assuming single TB, and not ITBs). This should come from the turbo's compressor housing (assuming there is a nipple on there, which there might well not be), or on the boost pipe somewhere between the turbo and the TB. On the pipe from the turbo to the intercooler is usually most convenient. The boost controller is then located between that boost source and the wastegate, ACCORDING TO THE CORRECT PLUMBING DRAWING FOR THAT BOOST CONTROLLER. There is no general diagram or instruction that will be correct for every case. Then the other ports on the plenum are for purposes such as Duncan described. If the boost controller has an internal MAP sensor, for a boost display, etc, then it will want to be hooked up there, alongside the ECU and the FPR.
    • eli995
      NPboosted manifold fitting purpose

      By eli995 · Posted

      Ok gotcha, so one post to fpr  another to bov  and I have the mishimoto boost controller and a link g4+ so I’d just have the tuner set it up properly. For the last two from plenum post throttle to  ecu/ boost controller, I know that I have a hose coming from the ecu that I was confused about so I assume that’s what connect to the boost controller from the ecu? And then the last is just from plenum to boost controller then to wastegate?
×
×
  • Create New...