Jump to content
SAU Community

Recommended Posts

Hey gurus. I have a bit of an issue.. 
s1 R33 Gts25t. Stock RB25DET . 
Apparently has :
a hypergear turbo, EBay 50mms external gate with a screamer , boost controller, fuel pressure regulator, 3" exhaust and a big fmic and a forward facing plenum.
Now the issue is it's running really rich and fuel economy is completely stuffed. The bov has been removed and the pipes been routed to the back of the intake manifold. I have changed my Ecu and maf, and it's still the same. 
I can unplug my tps and the car drives and.Runs normal, but if I unplug the maf the car stalls. Also if i squeeze the bov hose closed the car stalls... and honestly I'm lost as to where to look now. 
Any help would be awesome thanks.

IMG_20180611_093544.jpg

IMG_20180611_093554.jpg

IMG_20180611_093608.jpg

That whole setup is completely f**ked up.

The BOV return line routed to the back of the manifold is actually feeding the idle control valve.  Which is why it stalls if you crimp it.

You can't run a big turbo and altered fuel pressure etc etc against a stock R33 ECU.  It will tell you to go f**k yourself by making you fill up at every servo you pass.  This fits your description of your symptoms pretty well.  See above post.

thats what i was leaning towards haha , but ive not had time to look into the issues any further since i got the car. wheres the idle control meant to connect to? would be able to keep the hypergear turbo and sort out the bov/idle control piping?

The idle air control draws from the turbo inlet, via a combo of rubber and hardpipes that are attached to the original crossover inlet pipe arrangement.  The butchered plenum means that all that is gone, so the butcher found a way.  The BOV returns to the same place (turbo inlet, a separate port), so it's not incorrect for it to be hooked up the way that it is, just an ugly hack.

If you want a BOV back, you will need to attach it to the cold side intercooler pipe just before the TB and return it to the turbo inlet.  This is not strictly necessary - just depends on whether you like dose or like to have the inlet air bypass the turbo when on cruise (which is what it is actually for).

The main issue is the ECU.

54 minutes ago, Wrighty said:

thanks for help everyone, im thinking ill have to get a new ecu. but i still dont know why the car runs without the tps

Because the tps isn't a very important sensor for how 99. 9% of cars run

Original owner has wasted money on a FFP and a fuel regulator when what he NEEDED was bigger injectors and a tunable ecu...either a Link, adaptronic etc or for less money and a little investigation a Nistune set up.

  • 1 month later...
  • 7 months later...

fixed the IACV hose that was butchered by previous owner, also have worked out it just needs an ecu and a tune to sort the other issues out, has new coils and plugs now as well

52596074_10157017200191100_518463103076139008_n.jpg

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

    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
    • If they can dyno them, get them dyno'd, make sure they're not leaking, and if they look okay on the dyno and are performing relatively well, put them in the car.   If they're leaking oil etc, and you feel so inclined, open them up yourself and see what you can do to fix it. The main thing you're trying to do is replace the parts that perish, like seals. You're not attempting to change the valving. You might even be able to find somewhere that has the Tein parts/rebuild kit if you dig hard.
×
×
  • Create New...