Turbo Surge? Sounds Like On Engine Limiter..

[billy111]

Hi,

Just recently purchased a r32 skyline with a rb25det and I've noticed in high revs once the turbo is spooled it seems to surge like sound like the engine is on limiter when its close to the end of the rev range and I was wondering what is causing this?

Also sometimes my engine will misfire for say 10 or 20 minutes then run fine and was wondering if this was a common problem or could be related to firing such as coil packs or plugs?

Any help would be much appreciated..

Thanks Billy

Edited January 13, 2014 by billy111

[89CAL]

You'll need to give more info then that? What RPM is this surge sound? are you sure it isnt actually the limiter?

You say the engine will missfire for 10-20 mins, is this while its cold? randomly on and off?

[billy111]

Hi,

As soon as the tires spin around 6000rpm, a mate said it might be "valve float"

And it's more so when the car has been running for a bit at operating temp. Just randomly comes in for a bit then leaves.

Thanks for the reply

[89CAL]

what mods are done to the engine?

[scotty nm35]

So you aren't sure if it's compressor surge, valve float, misfire or limiter, and you would like an internet diagnosis?

Better get us a video, preferably doing skids...

[billy111]

Hahaha well by the way a mate explained it, it sounds like valve float.. It has a bigger turbo on it but pretty stock apart from front mount..

More concerned about the misfiring, I think it's weird how it just randomly starts missing then goes away.. Thinking its a damaged coil but just looking for ideas on where to start looking like if its a commonn problem or something

[Bennis]

By compressor surge do you mean this? (with foot on the gas)

http://www.youtube.com/watch?v=nCj6Spwl1CU

Or simply flutter like this?

http://www.youtube.com/watch?v=SF0JO9TfSjw

[Black4DR]

Sounds like a weak coil. Probably spark breaking down in the high rev range.

I hope for your engines sake its not detonating. Mine would clink when it was doing this.

[billy111]

Hi black4dr, what do you mean by detonating?

[niZmO_Man]

You have a lot of reading to do mate.

FIrstly, you said it has a bigger turbo, does it have aftermarket management?

Misfires could be coils, ECU, AFM, could be something else, who knows. You won't get a decent Internet diagnosis from the information you provided.

[Sklyn]

since you just purchased it, start with a *FULL* service. including all filters, plugs, fluids, at least checking sensors and coilpacks.

basically eliminate all the simple issues that don't get addressed by someone selling a car.

given its a R32 with an engine transplant I would hope it has had ecu changed as well, you need to know what it is because a larger turbo will require tuning.

[Black4DR]

Could be as simple as needing new plugs lol

Detonating is basically the fuel/air exploding. Smashes pistons and rings.... The technical term for detonation as "two flame fronts colliding". It can be cause by improper fuel miXture or preignition. Preignition is when the fuel ignites before its suppose to.

[billy111]

Thanks mate ill inspect the coils tomorrow by pulling them out looking for cracks and what not.. If it is detonating would it require a tune or what should I do?

[Black4DR]

Look out for white marks too, they indicate the spark arcing to earth. Check the plugs while your at it. The earth and the electrode should have nice sharp edges, not rounded. If the plugs look old replace them anyway. Cheap plugs are fine, stick to big brands like NGK and champion. Dont bother with iridiums

[billy111]

Thanks mate big help! Will let u know how I go tomorrow

[billy111]

Pulled off coil #1 and found it wasn't connecting with the plug properly and arcing out on it, heaps of white residue so fingers crossed its fixed!