Massive turbo help needed! gurus needed!

[Tictakman]

Well this is how it went down...

t3 turbo35mm tial wastegate w 8lbs springsafc II with -27 across the map- throttle low is 0 throttle high is 50.370cc injectors

the start up was fine, no stumbling at all. ran it down the road at about 1/4 throttle turned around drove down my street again(1/4 throttle) once again i turned around and gave it about 3/4 gas and let off completely. she stalled, no stumbling or anything just a flat out stall after i let off the gas. after that it wouldnt fire at all.

my buddy out side of the car said he saw a good amount of blue smoke(too rich?).

the engine turns over fine just doesnt seem to fire.

ive checked the spark on the spark plugs- goodchecked the injectors- seem to be fineturned over engine with just stock piping and had great vacuum.

i think im too rich, anyone else?

any help would be awesome!

Zak

[I am Technoman]

Are you using a stock fuel pump?

[bbandit]

i thought blue smoke is bad.. burning coolant or oil im not sure

black smoke = running rich

[NISMOingen]

blue smoke has nothing to do with your fuel. That's burning oil.

1st thing I'd do is a compression test.

Oh, bbandit, love the avatar.

[JBEES]

Blue smoke is a sure sign of oil burning. Compression test is highly advised at this point as NISMOingen suggested. Next see if you have spark. Check fuel pressure after that.

[WDRacing]

Pull your plug wire and turn it over, see if you get and spark. Disconnect the return fuel line and turn it over and see if you have fuel. If you have both and think you flooded the hell out of it, hold the throttle wide open, disconect your coil to the distributor and turn the motor over. The ECU won't let the injectors fire WOT on startup, so all the fuel and fumes will evac out the exhaust valves.

Reconnect everything and fire it up. If none of the above helps, do a compression test, but I highly doubt you blew your motor enough that it wouldn't start. I completely destroyed 3 pistons and my car would still drive.

It sounds electricle to me. But I'm only going with little info.

WD

[WDRacing]

Oh, check all your IC piping, if you blew one off it won't start. Had that happen quite a few times to me.

WD

[Tictakman]

well we know i have spark we did that test. ill have to check what your saying wd. i let it sit oever night to see if any gas would evaporate and maybe things would get better....

yes im using a stock fuel pump.

thanks guys.

Zak

[Tictakman]

alright, well today we did a compression test and it was around 50-70 on each cylinder. so we are thinking its piston rings or head gasket. im having the car towed to nissan tomorrow to see what they say. i leave in a week for school so i dont have time to mess with it myself.

any ideas on this?

Zak

[WDRacing]

Did you have the head off at all during your turbo install?? I can't believe your CR is that low in all the cylinders.

WD

[NISMOingen]

If compression is that far off on all cylinders then chances are you have damage to the valve train or head gasket. It will have to be something that provides containment to all cylinders equally. It is possible that damage to the crank could do that, but chances are it would have begun with an aweful boom.

My 1st stop would be pulling off the valve cover & taking a look. You can do it in less than an hour and it's easier to reset everything than pulling the head off. (plus damage to the head gasket would be unlikely to make the exhaust blue, burning coolant is usually more white in color)

[Tictakman]

ya there was no loud noise at all. just a stall like it idled down and didnt recover.

i didnt take off the heads during the install.

im having a buddy at nissan look at it tomorrow and tell me what he thinks. id would work on it but like i said i got to school in ten in less than a week so i dont have any time.

my dad told me that we may just get it fixed, sell this car and then lease one. so i may have a 240sx for sale w 30,000 miles on it.

Zak

[SloS13]

READ ME

Am I the only one that caught the fact that he's running totally stock fuel flow?

Sure he's got 370's and safc, but they are tuned to a completely stock configuration. He obviously ran super-lean and killed the motor! Or did i miss something completely and im coming off as retarded?

8psi + stock fuel = KA-BOOM sorry man

[Drift Machine]

To me it seems that j92s is right, or maybe I'm just retarded too.

[NISMOingen]

once again, there would have been an aweful noise. Plus all cylinders would not blow at once.

To happen as peacefully as it did, the damage would have to be to something very light-weight. Rings come to mind, but not all would have gone at once.

[SloS13]

once again, there would have been an aweful noise. Plus all cylinders would not blow at once.

:thinker maybe it was the silent, motor-killing fairy.:pface If it was the headgasket, it would have been followed by a billow of white, sweet smelling smoke, right? Sounds like headgasket though. That'd be my guess at the moment i guess.

[NISMOingen]

I agree. Head Gasket is a very likely cause. I just suggested checking the valvetrain first because he can do it in 30 minutes, and valve train is likely as well.

[WDRacing]

Stock fuel pump and 370 injectors doesn't equal a blown motor...Unless the SAFC was trimmed to the point where it would lean out. For the car to run lean enough to blow all the cylinders, or the damn HG in every cylinder you would have VERY audible detonation. Trust me I know...I've been through a ton of motors due to lean conditions caused soley by to much boost and not enough fuel. I'm not saying he couldn't have blown a HG or 1 maybe 2 cylinders. But you can get white smoke from other sources. Water jacket inside the engine, intake gasket leak, turbo seal leak. For the car to simply stall and not start again, it just sounds weird. If someone wants to help troubleshoot, they are only trying to help. We tend to welcome that sort of thing on this site. If I swapped a motor every time I got stumped by a problem I'd never be able to race.

WD

[Nathan]

I could be wrong, but if you think about it...it happened at 3/4 throttle, a point the S-AFC can not correct for, a place where the computer reverts to STOCK fuel maps. Yes you have 370cc injectors, but it still would not be as good as a proper map. This is why I just decided to do the JWT ecu...I dont trust big injectors run solely off of a stock map, stock timing etc. at 3/4 throttle. I think it could be the reason something blew for you.

[SloS13]

whoa? what?

at 3/4 throttle, the SAFC would use the hi-setting, seeing that its 75% and 75%>50%(high setting)

so you think that the SAFC will only work if the TPS reads exactly 50%?

The way I understand it, from 0-50%, the SAFC would use an algorythm to make a smooth transition from the low settings to the high settings, and the high settings would remain the same from 50% to WOT. Am I wrong?

[Nathan]

I dont know, I was unsure about whether it would kinda use some fuzzy math and make a smooth transition. I also was under the impression that it only had a part throttle and wide open throttle setting. I talked at length with Marc at Import-Autoperformance and learned that a lot of high boost wrx's using s-afc's to tune have burned holes in their pistons because of this issue.

Edit: I just feel uncomfortable with it because it's really a fine tuning instrument, not an engine management system...also, I have one but I cant read the instructions (japanese) to figure out EXACTLY how it works

[SloS13]

if I dont go standalone, im going to use injectors/pump/safc/FMU. Its nice to have at least something thats boost-dependent

[SloS13]

BTW - an easy way to test this theory is to just go WOT and monitor the correction % on the unit.

I think if this were the case, anybody running NA with 370s and -27% correction would run too rich to even burn the fuel that would be delivered at WOT (or anywhere over 50% or otherwise set hi-point throttle), which would be 27% over stock (if it reverted to the stock programming). Think about it...

[Nathan]

But the S-AFC is not boost dependent, it's throttle position/rpm dependent...If I use an MBC (which I will) then it'll go full boost at part throttle...the S-AFC wont know I need more fuel and poof...lean condition. Unfortunately, I cant test it...or else I would. The car has never run under my ownership...I havent even driven a 240 yet, just worked on one way too much

[SloS13]

I wasnt saying the SAFC was boost dependent. I was referring to the FMU. aka rising rate fuel pressure regulator.

an MBC is a manual boost controller, which simply 'hides' boost from the wastegate. I dont see how the MBC would make you go anymore full boost at part throttle than running a plain-ole wastegate...

[Nathan]

An MBC is more prone to going full boost at part throttle than an EBC (electronic boost controller) Your right though, it wont make it go full boost any sooner than running JUST the wastegate. I thought you might be talking about the FMU (yes, I DO know what they do, how the work etc )

Edit: I guess what I dont understand about the S-AFC is this:Do the high and low settings refer to >50% throttle for high and <50% throttle for low? Or is it a full throttle = high and low = part throttle using fuzzy math to make it a smooth transition up to the full throttle setting? Even if was either of those though, you would still possibly have problems getting full boost a 3/4 throttle...

[SloS13]

When i get my car back together, i'll do some experimenting with the SAFC although im pretty confident the hi-values (no matter what %throttle position its set at) will still be in effect from x%(hi setting) to 100%

[Nathan]

Can you set what % the high setting starts at? That darn thing is confusing...you'll have to let me know how it goes, I'll be VERY interested to see if I could have saved 200 bucks

[SloS13]

yeah, you can change the hi-low percentages. Because im running 370's, i had to change my low from 10% to 0% so i wouldnt idle 27% too rich. I'll let you know what i find out

[Nathan]

Good deal, I didnt know you could change that