Jump to content
SAU Community

Recommended Posts

Oh hey guys, I'm having a bit of trouble with my motor vehicle atm and im needing help...Here are the details of my vehicle:

R32 GTST

Rb25neo det (original turbo, ecu, etc.)

Rb25 gearbox (R33 box)

Random fuel pressure reg.

Boost t-piece

Bosch 400hp fuel pump + surge tank

aftermarket intercooler + piping

Heres the problem,

The car idles fine, sounds perfect, feels perfect. revs fine no worries standing still. When i drive its fine, until i hit about 2-3psi of boost. at this stage the engine starts to missfire like a tard. If i keep flooring it and manage to push to 5-6psi the engine stalls.

Things i've done to try and fix the problem:

Upgraded my fuel pump to the bosch 400 hp, originally thought there wasnt enough fuel getting to the engine. After installation problem got worse. I bought new spark plugs and made sure they were the correct gap. no change. Rreplaced all the rubber pipe connectors for the intercooler pipes as they were old and some had holes. Problem is stil aparent although now i have a sweet dose sound >_< ...checked all my vac hoses and such...ive visually inspected coil plugs and found no signs of cracking or burns from arcing out but will check tomorrow propperly...

other random problem:

When i first drove the car with the new engine in, i noticed the wastegate to the turbo was opening straight away. ??? i borrowed my mates t piece to combat this??? maybe this has something to do with the problem im not sure...

I would really appreciate advise as im sick and tired of seeing my car on the side of the road...WANT TO CRUISE!!!

Thanks, Edward

Link to comment
https://www.sau.com.au/forums/topic/333996-r32-neo-disaster/
Share on other sites

it sounds like its leaking un-metered air in somewhere...

if you take the vac line off the pre intercooler pipe (just after it leave turbo ill c it..)

stick a normal size can of tomatoes or sumthing in your intake... tighten it up air tight.

pump up the nipple with a bike pump to what boost your running... let it sit there for a bit, it shouldn't leak at all.

alternatively, ur really chasing a leak i believe... so wack a bit of pressure in it.. and listen out... if your finding it heaps hard to find a little trick is to use a hose, and put one end to your ear, other end to what ur listening to... will amplify the sound...

obviously do this after checking all the usual clamps afm is bolted up nice etc etc...

I had a similar problem with mine when I installed an aftermarket fuel pump & wound the boost up, turns out the std injectors were bein pushed too hard with larger than normal fuel pressure & were in-effective at giving a proper spray pattern at low rpms but would come fine once the motor started to rev to.

Dont know if that helps or not

To fix it I got a Nistune-new injectors(660cc), changed fuel pump from Walbro to a Nismo pump, added a Sard FPR, changed plugs to copper & gapped the plugs to 0.7mm

I had a similar problem with mine when I installed an aftermarket fuel pump & wound the boost up, turns out the std injectors were bein pushed too hard with larger than normal fuel pressure & were in-effective at giving a proper spray pattern at low rpms but would come fine once the motor started to rev to.

Dont know if that helps or not

To fix it I got a Nistune-new injectors(660cc), changed fuel pump from Walbro to a Nismo pump, added a Sard FPR, changed plugs to copper & gapped the plugs to 0.7mm

Changing pumps does not affect the pressure at the fuel rail as that is governed by the fuel pressure regulator (hence its' name).. UNLESS the old pump had inadequate pressure and the ECU was tuned around this.. then by fitting a properly operating pump the fuel pressure goes back up to what it should be but because the ECU was tuned around the old pump, there is suddenly a lot more fuel going in.

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

    • I might be way off the mark here.. there must be a T junction under the manifold. That takes manifold pressure through a check valve prior to the T, one side splits out to this bleed off orifice, the other straight to the wastegate actuators. 
    • Carrying out some engine due diligence before my first drive in a 260RS that has been in storage for 10+ years, and found two lines that are susposed to be plumbed into the boost control solenoid. One of the lines (the wastegate boost supply line) to actuate the gates, had a bolt in one end blocking it. The other line (main boost signal line) from the very rear of the intake manifold (RB26DETT) and runs up to the boost controller had this pill in the end of it as seen in photos. Other than the obvious (T28 Ceramic turbos might well be cooked)  Can anyone shed any light on if there is any validity at all with this mod, bleeding a constant fixed rate of manifold boost pressure off through this 3mm hole?  Is it deliberate?  Was this a 90s Jap mod done to RB26's? Or has someone just fitted this without any idea of what happens to ceramic T28s if they are not gate controlled?    
    • This looks great! Awesome to have the 5 speed with an LSD in this. The Recaro's look like SR2's or SR3's. It's a shame they've been retrimmed as they would have looked sweet in their original colours. I think I'd want my agent to be a little more up front and informative too. I've never imported but I reckon it would make me a little nervous, so the more info the better.
    • Thanks for doing that Duncan! Makes you a good person in my books. We don't get kangaroos or wombats here. But we have bats and it's similar. AFAIK it's often the mums with a baby attached that get hit because they drop lower when starting from a tree. If you hit an animal, check on it. https://www.ifaw.org/au/resources/wildlife-rescue-app An app to get the closest wildlife rescue contact.
×
×
  • Create New...