Jump to content
SAU Community

Recommended Posts

well i got my rb25det r31 and it free revs well.

But once you put load on it driving it starts to rev and then breaks down and wont rev, and starts backfiring as if it was a limiter noise...

when you change gears the bov makes a high pitched whistle instead of the normal rb25det bov noise, but thats in 1st and 2nd but from 2nd to 3rd and 3rd to 4th and 4th to 5th it makes the normal noises...

and when you do the limiter revving under load noise when you put the clutch in the revs drop down then it revs back up

free revs all the way out but wont rev under load

what could it be?

Link to comment
https://www.sau.com.au/forums/topic/160907-rb25det-breaks-down-under-load/
Share on other sites

coil packs or spark plugs. there are a few different fixes for the misfiring problem.

#1 - gap your spark plugs to .8mm (do that if not already done)

#2 - fix your coil packs, there are a few threads around on how to do this.

as for the bov sound, im not too sure if this fits the sound you described but it might be turbo chatter, where your bov doesnt actually open, the noise you're hearing is the air passing back onto the turbo blades.

Hey you are reading my mind but about four months earlier, If you have played with intercooler and a boost controller on the car you would have noticed that a nipple would be missing on the inlet part of the pipe before the bov that is the vacuum pipe that opens the actuator on the internal waste gate and if you dont have that hooked up you will hit max load causing seveire breakdown at 2k trust me i had the exact problem!!! easy way to fix it is to simply put a T valve in on the blow off valve hose that goes to near the back of the plenum!! that will get rid of your break down at 2k.. P.M if ya want a photo!

made a slight difference but still breaks down, but you can get past the banging and then it tries to pull.. could it be a fuel problem?

but what concerns me is, i gave it a boot full and then went to go into my driveway, stopped and the car stalled, then i started it again and it stalled again but started it and gave it a rev and it idled fine...

its quite farken easy u see...

u get a gapping tool, pick the gap u want, get ur spark plug out, tap them on the ground softly until the gapping ruler u are using fits between the sparking element and the underside of the tip. ur spark plugs come pregapped at 1.1 thats not enough for boost past 6-7psi. that will work, if ur unsure how to do it, go to ur mechanic.

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

    • Old Son, did you re-use the Holden ABS in the new shell or try a different module?
    • Yeah, nah. I had the actuator rod off it today. The arm will not move at all. Neither out, nor in. Yeah, you'd think so, but I've been thinking about that. Even when the actuator rod fell all the way off at the beginning of this saga, it would build more boost and faster in lower gears than it would in higher gears, and you'd think that that was the opposite of what should happen. But I strongly suspect that there is a thing with the gearing getting the revs to rise faster, that there must be some transient effect with the gas flow rate rising quickly, that you don't get with the more steady state case of the higher gears. Keep in mind - the gate is not shut in either of my weirdnesses. So things are not "normal". We normally think about a turbo spooling up (below the wastegate target) with the gate shut. I have all sorts of mental models running now where the gate is a little bit open, and having it stuck open allowing gas out while it should be going through the turbine has all sorts of weird effects (in these mental models). I'm thinking in the higher gears, the ex mani pressure builds to the point where enough gases spill out the wastegate to just prevent the pressure rising much more at all, or just creeping up, all the whole the revs are increasing and getting closer to the point where a gear shift becomes necessary.
    • Is it possibly wastegate actuator itself is sticking, or even the rod to flapper? Otherwise I reckon things are getting a bit rusty/worn   Also odd it won't boost in 3rd to 5th, but will in 1st, I'd expect the other way around with it slightly open as there's more time on your way to redline for it to spin up
    • Does anyone know ow what these two plugs are for and if they should be unplugged? Just put the dash back together and can't remember if these were plugged in before or unplugged! (Blue and white plugs) 🤦🏽‍♂️
    • Did some FASTing ...got the impression that the actual part# was a moot point ; seems all of these hardlines for coolant are discontinued/NLA... like, I take it you're after the hardline that bolts onto to the manifold...that's NLA according to amayama & nengun .... ...just to clear up some confusion, they typically mounted the AAC valve to the intake manifold somewhere near a coolant passage, so the body of the valve heats up & holds it open when engine's up to temp - no coolant flows through the valve, it's a mechanical, thermal connection.
×
×
  • Create New...