Revving Problem That Can't Be Diagnosed So Far...

[Slapstik]

Hi all,

I have a re-occuring problem with my R33. When under full throttle, when it reaches 4500rpm the revs almost come to a halt and the engine feels like it's really struggling.

So far, it has been currently un-diagnosed as to what it is.

I have changed the AFM, coil packs, CAS, fuel pump and had a HKS twin power unit installed incase of ignition breakdown, all to no avail.

the ECU reads 55 in diagnostic which is no fault.

I'm starting to go out of my mind, anyone else encountered the same or similar problem??

any help would be greatly appreciated!

[ssshonky]

whats your air filter looking like? tried replacing it?

a mate of mine had a really weird problem where the car was basically making no power.

turned out the air filter was being sucked onto the intake pipe

maybe thats it?

also I know on the Stageas ( thats what I drive ) the intake pipe would " suck shut " basically implode on it self - thus causing problems.

maybe it could be that ?

I know its a bit of extra expense.. but why not stick it on a dyno and get em to do a few runs

they connect all sorts of sensors in the dyno that might be able to tell you something

you dont reckon its boost cut do you?

Edited April 14, 2008 by ssshonky

[Habler]

spark plugs?.... lots of possibilites..

[Slapstik]

had a look at my air filter, looks fine, grubby, but not overly. I'll give it a clean whilst i'm at it and see how that goes.

Have already fixed the inlet pipe from sucking closed by replacing ribbed section with solid piping.

Boost is 6.5psi low and usually 8psi high, so shouldn't be boostcut, but stranger things have happened...

Was thinking maybe an ECU input is kaput, as It'll run fine at some points, sometimes for hours on end but turn it off and it runs like a pig up top again.

So far spark plugs are about 10,000km old. re-gapped them recently to .7 and looked fine.

Maybe Dyno is going to be the only way to go.. bugger!

[_Ryan_]

fuel filter?

does it do it on low boost?

search "rich and retard" "R&R"

also, where do you find out what fault codes mean?

-Ryan

[Richieb]

Cam timing?, CAT Blown apart inside, and blocking zorst.

OR even one of the silencers disintegrated internally, and blocking the ZORST..!!

Edited April 14, 2008 by Richieb

[Slapstik]

Cleaned the air filter to no avail.

Fuel filter was replaced 5,000km ago, Will have a search for "rich and retard"

Was prompted by a mechanic to check my cat and now it's currently non existent.

Have a catback exhaust on it, only 20,000km old and with no cat is just straight through unless there is a second cat i don't know about..?

Could possibly be the cam timing..

dyno is still looking like the best bet

[Luciano]

what sparkys are you running?

[Slapstik]

NGK Iridiums at the moment

[r32line]

Deff a dyno - tells you so much so quickly particularly when you go to someone who knows their shit!

[Luciano]

before you get the car dyno'd, go to motor traders and buy 6x BCPR6ES-11 or BCPR7ES-11 NGK sparkys (which should cost you no more than $40), gap them to 0.7-0.8, install. Take your car for a drive. If it still has the problem, then book in for a dyno tune.