R32 Neo Disaster

[SickSUB]

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

[chef_stagea]

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...

[Sheriff Wan]

What about fuel filter and reg? Even though the new pump can supply it, doesn't mean it's getting there... Swap them out for known working units and see how you go.

[DVS JEZ]

Get it on a dyno

[bubba]

Random fuel pressure reg?? is it adjustable? is it 1:1?

Sounds like it's coming on to boost and dumping way too much fuel in.. i.e. could it be a 2:1 reg?

Edited August 24, 2010 by bubba

[kjb_r33]

Air leak it wouldn't idle fine, problem occurs on boost. Id be inclined to verify pressure reg type as bubba said.

[toddlls]

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

[bubba]

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.

[lachlanw]

or could be afm .

and you need to explain what your on about with "the waste gate opens up to the turbo" think you have the wrong names for things