Surge and Flames!!!

[laujik]

RB25DETStock TurboGreddy B spec 2 (12psi)3inch straight pipe to evo TTFMICStock radK&N cone filter

So about 2 months ago whenever I was boosting between 7 - 12psi and above 4500rpms I would get crazy surging and backfiring. Which it was running perfect, even with a EBC and it just started coming from no where. My friend also said that during those higher rpms, huge flames were spitting out the back and I lost alot of power.

So I replaced all the plugs with ngk plats, checked filter, checked for leaks as well as i could, replaced o2 sensor and tightened up all IC piping sleeves. I was driving today and its still surging a bit at same rpms. Its not as bad and I can afford to fix it, I just dont know whats causing it or what else I can check.

Im in the process of getting a bung welded in and putting installing an LM-1. But I have absoluetly no clue at this point of why its happening. I was told if its colder out you will get some comp surge but its running better now just before winter than it was mid summer.

Thanks Matt

EDIT: After 6-7psi boost gauge starts to flicker
Modified by laujik at 11:07 PM 9/12/2007

[lilskyline240]

disconnect the boost controller. run just off the wastegate and then see if it stops your problem. seems to me like your boost controller is takin a crap

if that dont solve it try a diff maf

[laujik]

Ill try to disconnect the EBC and see how that goes. Or even try to find a manual to test. But the boost is solid and doesnt seem to be leaking on the electronic side. But one thing i forgot to mention was that my Boost gauge starts to flicker after i build boost past 6-7psi. It doesnt go all over the place, just shutters really rapidly.

Im thinking of just saying screw it and getting a z32 maf and a power fc.

[240z4u]

Throwing parts at it is the wrong way to go about trying to find the problem. It seems to rarely help me find a problem unless I have gone through the effort to troubleshoot it.

Take some time and figure it out. Sounds to me like you are running very rich. I think your LM1 is really going to help you find out whats going on.

Evan

It could also be your crank angle sensor, check your base timing first. Make sure the tang isnt busted of the cas.

[lilskyline240]

before you spend all that money try and run just off the wastegate. stock boost. see if it still does it. Before spendin money on a power FC and z32 maf just try to swap maf's with someone local and see if thats actually your problem. worst thing that can happen is you buy a z32 maf and power FC and your problem still isnt solved.

Fix problems first, then upgrade

Ben

240z4u ~ not too many RB guys in Wisconsin, you ever come to the milwaukee area? id like to check your your car

[240z4u]

I actually don't go that way too often. I am really trying hard to get to Great Lakes soon though before it closes.

I can give you a PM if I am going to be in town, I would be happy to show you my car.

Evan

[laujik]

Thanks alot for your help guys, Im going my apprenticeship now so I should really know that you need to troubleshoot before you start digging into things, but apparently it doesnt apply to my own car .

Im going to get a z32 and pfc anyways, but I really agree with fixing the problem before throwing new parts at it.

Just to clarify; if i run off just my wastegate and its fine, does that mean my ebc/solenoid is screwed? And if thats not the problem, could it be the actual wastegate? How would the maf help and what would it mean if switched mafs out with a friend?

BTW im running an ssqv since i installed it and not sure if its starting to cause problems. I know i run rich, but didnt know i would start surging because of it.

Also sorry for long posts, but this is just driving me insane, what do you mean by "thang" on the cas. Connection terminal?

Matt

PS: I tried to look up similar posts and information about possible wg and ebc damage and it didnt help much.

[lilskyline240]

well why didnt you say the problem happned after you put on the BOV? thats more than likely your problem. Probably a faulty BOV where air is leaking past it when you go into boost making a rich condition causing you to surge and backfire. unless its a REAL hks SSQ then its more than likely leaking at 7psi

switching mafs with someone else is to see if that changes your problem. means your maf is bad

DO NOT SPEND MONEY ON MODS UNLESS YOUR PROBLEM IS FIXED!! trust me. nothing good will come of it. all that will happen is you will have a ton of cool mods that arent makin you any faster cuz your car still has the same problem

[laujik]

Well what i meant was that ive had the bov since i installed the engine. And it was running perfect for months and months. This only happened about 1 month in a half ago, so it might have started to leak a few weeks after i started boosting 12psi?

And what do you mean by REAL ssqv haha, are they common for leaking like that?

It would explain why its surging only after 7psi, my boost flickers cause of a leak that i suspected, and backfires etc.

Is there anyway to test it though? Cause its pretty high boost and I did a smoke test but it obviously wouldnt show up if its only under high pressure. Going to have to try a diff bov maybe?

Thanks again,Matt

[240z4u]

You need to build a boost leak tester. Search the forums. its been covered.

It basically involves pressurizing the system from the air filter area to find air leaks. It will tell you exactly whats going on.

He meant REAL bov in the sense that there are craploads of fakes out there .

Sounds like you do have a boost leak, it does not have to be huge to throw everything off fuel curve wise.

Evan

[Abdo]

silly question i know..but are you sure your plugs are gapped properly?

[l0nestar]

Also sorry for long posts, but this is just driving me insane, what do you mean by "thang" on the cas. Connection terminal?

Matt,

TANG - or shaft of the CAS. Where it interfaces with the cam. You are thinking of the wrong end

Throwing hardware at a problem to try and solve it is a bad idea.

[l0nestar]

DIY Boost leak Tester:

zerothread?id=158784

Pretty cool, and yet so simple!

[lilskyline240]

Real one says HKS on it. FAKE one doesnt

[laujik]

Thanks alot guys and yes lonestar, im always thinking of the wrong end !

Im going to make one tommorow morning and see wahts going on. You never know it might be as simple as my intercooler leaking. Today I tried running off stock boost from wg and no ebc and didnt change anything. (not high enough boost to cause the surging and backfiring) It runs the same way as when i run stock boost from ebc.

So im going to try and pressure test it tommorow and see whats going on. If i find something im going to kiss all of you! In a very non gay way. But if its still leaking im going to borrow a maf and see if that helps.

Thanks for all your help again and ill update you with what happened.

Also its a real ssqv, but might just be faulty or starting leaking out of no where. Im really starting to think it might be my IC. Ive learned that it doesnt take much.

Matt

[lilskyline240]

So if you run stock boost it doesnt surge and backfire?

if this is the case its more than likely a boost leak when you get over 7psi. if thats not the case, id also try using some colder plugs

[laujik]

Im just going to the store now on lunch to get some stuff to make a leak tester. Im just goign to just my intake though cause its a pain to try to fit one on there.

But yes, even with the EBC, if i run stock boost or just run it with the controller turned off, it doesnt backfire and runs solid. But when i start to boost over 10 it starts to mess up.

Ill find out soon. Hmm who makes good colder plugs? Ill just search up some threads about them later.

Matt

[lilskyline240]

probably a boost leak

[laujik]

Is it common for intake gaskets (coming from my compressor) to start leaking? Cause I took off to get at the intake going to my turbo and then put it back on and its the only leak i could find. But im not sure if its because I took it off. Ive never really had that happen to me though with any other gasket, so It could be the problem. I just need to track down a new gasket i guess.

[lilskyline240]

could be. Did you pressurize your intake system up to like 15psi?

[laujik]

Yah i pressured it up to like 15-17psi and its the only place i could tell where it was leaking from. I only had thin thin gasket paper so it didnt seem to seal and i had to get it going last night. And it seems to be doing the same thing. So im going right now to get a little thicker gasket paper and cut one out and see if that helps. It looks pretty dried out so you never know.

Well see i guess! haha

Matt

[lilskyline240]

if your leak tester is made right you should be able to pressurize your system to 15psi and it should stay there, and maybe drop VERY slowly. instead of using a paper gasket, get RTV silicone and make the gasket