Rb25det

[AdamsR33]

Okay i have done a search for hesitation and loss of power, but none of these have helped me.

The car as you can see in my sig is a 33 s2, mods are,

3inch from turbo back,

FMIC

spiltfire coils

walbro fuel pump

boost controller and

pod filter.

Now my prob is when i give it a boot full the motor seems to "struggle" until it hits about 4-4500rpm, boost is set at 8psi, so my initial thought is timing playing up... as once the variable timing kicks in at 4000rpm or 4500rpm, whichever one it is, it is like boost kicks in and you get full power again. This is in atleast 1st, 2nd and third gears so assuming it does it in all gears. Coil packs and spark plugs are only 2mths old so i don't think it is any of them as its not a miss.

It feels as though i've lost power as the car takes forever now to get to 4000rpm, but as stated before once it hits 4k it like the turbo kicks in. IT is the standard turbo by the way and i have full boost by 3000rpm as the boost controller bypasses the factory solenoid. ECU is also stock. Maybe my CAS is playing up??? or my O2 sensor, these are things that other people had problems with that i found in the searches i did, but the problems these people had aren't the same as my problem.

Its like when a N/A motor struggles in the top end of the rev range, like when the carby isn't supplying enough fuel or not flowing enough air, but i can't see it being a problem with the fuel as the pump is also 2mths old and once it get past 4500rpm it goes all the way to redline like a scalded cat.

This has only just started to happen in the last week or so.

Any help would be appreciated

Cheers Adam.

[Devils_Advocate21]

Ummmm have you changed anything in the last week or so before the problem, may have direct connection to the source of the problem

[AdamsR33]

Ummmm have you changed anything in the last week or so before the problem, may have direct connection to the source of the problem

Nah nothing, also don't think it is a bad batch of fuel as its had a couple of tank fulls since it started.

[Ryanrb25]

in most cases when people complain about their rb25's runnin sick its usually directed at the ECU playing tricks with timing etc (like you said). This usually doesnt effect the bottom end power what so ever. It has the same symptoms as what your describing, like it feels like your towing a boat. I'd start with the simple things. Try by gapping your spark plugs to .7mm but usually this doesnt effect anything under 9-10psi but give it a go anyways. Then maybe get a timing light and sus out what static timing your CAS is set at.

[AdamsR33]

in most cases when people complain about their rb25's runnin sick its usually directed at the ECU playing tricks with timing etc (like you said). This usually doesnt effect the bottom end power what so ever. It has the same symptoms as what your describing, like it feels like your towing a boat. I'd start with the simple things. Try by gapping your spark plugs to .7mm but usually this doesnt effect anything under 9-10psi but give it a go anyways. Then maybe get a timing light and sus out what static timing your CAS is set at.

Sorry should have posted plugs are gapped at 0.9mm, i don't think going smaller will fix the problem, as stated i have splitfire coils and 8psi so should be heaps of spark. As stated before also plugs are only 2mths old and have been gapped at 0.9mm since new, problems has only just started in the last week or so.

But yes i think i'll try the timing light and see what it is.

[Taso84]

Im very curious as to what this could be.

Just to clarify:

1) After u hit boost 4-4500rpm, does the car pull as hard as it used to?

2) How long ago did u do ur boost controller?

My opinion is that chances are, uve got urself a boost leak (mayb from the boost controller instal).

On a stock turbo, u should begin spooling at around 2.5 and be at full boost by before 3.5. If ur not hitting boost till 4.5, this would indicate that ur leaking a significant amount of psi.

After u start to get positive pressure in the throttle body, the car will feel normal. You should be able to realise this is happening if its happening because ur hear ur turbo spooling while ur gauge is still reading 0 or below.

[AdamsR33]

Im very curious as to what this could be.

Just to clarify:

1) After u hit boost 4-4500rpm, does the car pull as hard as it used to?

2) How long ago did u do ur boost controller?

My opinion is that chances are, uve got urself a boost leak (mayb from the boost controller instal).

On a stock turbo, u should begin spooling at around 2.5 and be at full boost by before 3.5. If ur not hitting boost till 4.5, this would indicate that ur leaking a significant amount of psi.

After u start to get positive pressure in the throttle body, the car will feel normal. You should be able to realise this is happening if its happening because ur hear ur turbo spooling while ur gauge is still reading 0 or below.

I hit full boost by 2700-3000rpm, boost controller was done 6-7 mths ago, what i was trying to say was the problem feels like i hit boost at 4500rpm , thats how it seems, but i hit full boost by 3000rpm, as stated all stock turbo, ecu and psi.

Once past 4500rpm the car pulls just like it use to, but before that it struggles so to speak.

[MBS206]

What boost controller are you running?

[AdamsR33]

What boost controller are you running?

GFB dual stage, low boost is set at 8psi and high boost at 13psi, though i don't use high boost at the moment, not until i get the PFC in. And no switch isn't set on high.

[Zas)-(]

man this stuff happens to mine

heres my answer of what i've noticed ok..

first time it happens = played around with idle screw just for fun? it fixed it up ( just luck )

2nd time it started happening = rich and retarded ecu shit itself got a new ecu everything was fixed no lag before 4 thousand rpm

3rd = right now...... using idle screw adjust to allow more air has kinda made it better but not quit still it does it,

try da idle screw? all da way low den keep adjusting? mite fix?

or else go and buy a new ecu for 50 bucks and it'll work normal <---

till it stuffs up again so maybe get ur ecu tuned??? thats what im doing now , i hate my stock ecu shitting itself all da time

of course its from running higher boost

[Dale FZ1]

Sounds like the ECU is in failsafe. Engine is breathing far better than stock, so it serves up a massively retarded ignition map to discourage any behaviour thta might damage the engine.

And as pointed out, changing the ECU may give a cure but it will be (very) temporary.

Many people (myself included) have hit the same hurdle by adding intake/exhaust/FMIC alone - no boost increase. And it is frustrating.

[NYTSKY]

Had the same problem on mine.Its your ECU.Once you start modifying your car the ECU starts playing silly buggers.Time for an aftermarket ECU mate.

I put in a Power FC no probs now.

[Dale FZ1]

Likewise. PFC opened the performance lid for me.

In some ways it's a pity the R33 ECU is too difficult to alter. The results being pulled from R32 spec remaps are very noteworthy.

Whether PFC is becoming scarce, the options are still wide open.

[SKYHY]

yer dude I had the same problem I lived with the problem for about 4 months then I got myself a cheap pfc and bang the basic factory default maps on the pfc worked fine fixed all the retarding the stock ecu was creating I feel the extra power much more now best invesment I ever made buying the pfc go apexi!!

[AdamsR33]

Yeah got a PFC sitting in the cupboard waiting to go in, so yeah i'll just get it installed. Thanks guys, once i install it i'll post my results.

[AdamsR33]

Hey just changed my fuel filter and you should of seen the color of the fuel that came out! it was black!!! car was starving of fuel, now all is okay. man i'm glad i fixed it now and not after the thing leaned out to the point of blowing something!

[evil_weevil]

did that help also Adam?

I found with mine, my car was running similar to how you described.

I had standard fuel pump though and was cutting out - couldnt handle the new power levels.

Now, I got a walbro also and the powerFC and tuned - car has felt freakin strong since, but only this evening, went to start it after a few dyas of not using it, and cold start - splattered and splurred - but after a few mins was back to normal.

Hurry up and get it tuned!!!!!