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: turbo not boosting!!!


rivalbro
04-23-2011, 01:24 PM
Alrite, many of you know my turbo from my built thread if not then please visit it for details of the turbo (http://www.preludepower.com/forums/showthread.php?t=340805) so i can directly ask my question/problem:

I received my LM-2 after PLX going bad on me so i went for a tuning session. at the tuning, as i accelerate for WOT, after 1.5 psi, my car would feel to go to neutral and get to 10+ psi from MAP of my neptune without any power.
Anyways, i tried fiddeling with boost controller, removing it and then placing it back again but nothing helped.

at the end, i heard a backfire and my car stopped boosting, i dont hear the loud turbo spool (i can see the turbo moving tho), i can hear the turbo spool very quietly tho. but there is not swishhhhhh sound of BOV and i m not building boost more than 1psi anymore.

what could be the problem? wastegate (stuck)? turbo itself? i hear no air leak...

viper_boy403
04-23-2011, 01:46 PM
do you have a good basemap? what does the air-fuel ratio look like in boost?

As for the no boost issue, check all your couplers, that "backfire" could have been a coupler blowing off

rivalbro
04-23-2011, 11:00 PM
do you have a good basemap? what does the air-fuel ratio look like in boost?

As for the no boost issue, check all your couplers, that "backfire" could have been a coupler blowing off

I Checked the couplers to the intake from turbo, all of them were intact with no leaks. the AFR is between 9.5 and 11 in boost as it shoots up, but before shooting up it is between 11.5 and 12.5

Basemap is a very good one from neptune. AFR was always on rich side of all between 11 and 12.7 where i leaned it down to between 11.5 and 12.5. because of that boost problem i wasnt able to play with the tuning a lot

rivalbro
04-23-2011, 11:30 PM
I'm quite sure the waste gate has taken a dump here as the turbo does spool but no pressure is built.

Checked for leaks but all pipes are intact. Wideband is working correctly.

I think, in my theory, WG was allowing more than 6psi into the engine, the map sensor was shutting the intake off, thus the neutral revving when boost went above 11 psi. The back fire must've killed the WG making it stuck open so now there's no boost.

Anyone confirms this theory?

The new exhaust has made VTEC come alive though. I've tried tuning without VTEC and it was the same result before the backfire happened.

91JDMsi
04-24-2011, 12:20 AM
I'm quite sure the waste gate has taken a dump here as the turbo does spool but no pressure is built.

Checked for leaks but all pipes are intact. Wideband is working correctly.

I think, in my theory, WG was allowing more than 6psi into the engine, the map sensor was shutting the intake off, thus the neutral revving when boost went above 11 psi. The back fire must've killed the WG making it stuck open so now there's no boost.

Anyone confirms this theory?

The new exhaust has made VTEC come alive though. I've tried tuning without VTEC and it was the same result before the backfire happened.


You should check the fire ring at the waste gate valve on the bottom .

viper_boy403
04-24-2011, 01:26 AM
yeah, just take off the wastegate and check it out. If that looks fine, take it apart and check the diaphragm. Stock map sensor doesnt read much over 10psi so it will cut out if it goes past that.

the "neutral revving" could have been clutch slip

rivalbro
04-24-2011, 08:04 AM
but that neutral reving only happens past 1.5PSI boost, will that have to do with clutch?

viper_boy403
04-24-2011, 11:12 AM
more boost=more power, and if you're on a stock clutch it can slip

rivalbro
04-24-2011, 01:07 PM
could it be a boost creep possibly?

g-gameslude
04-24-2011, 01:55 PM
no. the ebay turbo could be blown or the wastegate spring/diaphram is probably fucked.

LUDE_4_LIFE
04-24-2011, 02:59 PM
If the wastegate doesn't open, the car will over boost. I doubt it is sitting open, but you could pull off the pipe and find out.

The turbo could very well be blown. It might spin, but if the bearing assembly is fucked the turbo can't spin fast enough to build boost.

How are you AFR's cruising now? Is the car running really rich?

Do you have a CAT? Your CAT could be clogged to shit as well.

LudeBB6
04-24-2011, 07:17 PM
My bet is the turbo took a dump, I've heard this story so many times and generally why people suggest avoiding them. Hopefully it's not the case and maybe it's something small and easy to fix though.

viper_boy403
04-24-2011, 07:30 PM
my friend has a mk3 supra that bought a bolt-on replacement ebay turbo. ran fine for about a week then stopped building boost one day; the wheels had ground into the housing. ebay turbo FTL, you basically always end up paying more in the end

rivalbro
04-24-2011, 11:55 PM
no. the ebay turbo could be blown or the wastegate spring/diaphram is probably fucked.

I will check the wastegate spring, hope its easy to check...how would i know turbo is fucked? any way to say?

If the wastegate doesn't open, the car will over boost. I doubt it is sitting open, but you could pull off the pipe and find out.

The turbo could very well be blown. It might spin, but if the bearing assembly is fucked the turbo can't spin fast enough to build boost.

How are you AFR's cruising now? Is the car running really rich?

Do you have a CAT? Your CAT could be clogged to shit as well.

i will check the wastegate as i said,

AFR at cruising is rich yes, gone to 9 - 11 from 11.5 to 12.5

No CAT

My bet is the turbo took a dump, I've heard this story so many times and generally why people suggest avoiding them. Hopefully it's not the case and maybe it's something small and easy to fix though.

How do i know its the turbo? how do i check it?

my friend has a mk3 supra that bought a bolt-on replacement ebay turbo. ran fine for about a week then stopped building boost one day; the wheels had ground into the housing. ebay turbo FTL, you basically always end up paying more in the end

Thank you, but how do i know if the turbo is gone bad...

by the way, this is not the first ebay turbo we using, we have a ebay turbo .63 AR on a 2JZGT single Turbo for a year now...it has done more than 10,000km on that turbo and is still running...i am saying that 2jz because its been with us for long, other than that we have installed ebay turbo's on many other cars...maybe my luck but how do i check?

viper_boy403
04-24-2011, 11:58 PM
pull the intake off the turbo and check the wheel for play

hjdanzi
04-25-2011, 01:59 PM
First off... with the car idling, put your hand in the BOV discharge and feel if there is coming out... if you have a leak in the BOV it will never build up boost... Btw... can you tell me how much inhcg of vacuum does the car have while idling?

viper_boy403
04-25-2011, 02:13 PM
First off... with the car idling, put your hand in the BOV discharge and feel if there is coming out... if you have a leak in the BOV it will never build up boost...

My BOV is 100% open at idle and blowing air out, thats perfectly fine on MAP cars. If he blips the throttle, it should close though

hjdanzi
04-25-2011, 02:29 PM
My BOV is 100% open at idle and blowing air out, thats perfectly fine on MAP cars. If he blips the throttle, it should close though

Im sorry, but thats not perfectly fine. In the last 10 turbo cars ive tuned, the bov doesnt blow air out while idling unless you have a bumpy idle. IF its blowing air off it has a leak. Anyway... what ive meant for him, is to see if the bov have leaks.

viper_boy403
04-25-2011, 04:35 PM
I know you think you know everything since you started tuning cars, but you are wrong in this situation. It's normal for certain BOVs to be open at idle. They close as soon as any throttle is applied. Does not mean there is a leak.

If he blips the throttle and THEN it doesnt close, he has a problem.

hjdanzi
04-25-2011, 05:16 PM
I know you think you know everything since you started tuning cars, but you are wrong in this situation. It's normal for certain BOVs to be open at idle. They close as soon as any throttle is applied. Does not mean there is a leak.

If he blips the throttle and THEN it doesnt close, he has a problem.

hahahha.. I was 100% expecting that kind of answer from you... This is not the first time... If I say something different from what you think, then you give me those smart ass comments.

1) From all the people in this forum, if there is somebody who is always saying that "he doesnt know shit and he is always learning" its me... So im sorry, but you couldnt be MORE WRONG about that smart ass phrase you gave me... I DONT THINK I KNOW IT ALL.

2) I just said that about tuning.. cause it happens that i have a turbo car... AND IT NEVER LEAKED AT IDLE... and recently... since i had a turbo civic i couldnt fix (now i fixed it)... i went out and checked a lot of turbo cars, like my buddys 97 boosted prelude, a turbo hatch and many others that are visible in my webpage.. and did the exact same thing to check the bov... and they didnt leak.... THIS CIVIC I SAID I COULDNT FIX.. leaked.. and that gave me a low vacuum idle (you remember the car right=.. and I SAID THERE it was leaking.... after i replaced the bov... NO MORE AIR ESCAPED, and the problem was fixed... THATS WHY I SAID ALL THAT... NOT TO ANNOY YOU, AND NOT TO SHOW THAT I KNOW SOMETHING... WHICH BTW.. I DO KNOW SOMETHINGS...

3) So since you know everything, and you always knew..since you were born.. then, i suggest making a forum just for you to answer qurestions... And i say this.. cause i just said something, and you are saying in public.. FOR EVERYONE TO READ IT... that "I THINK I KNOW EVERYTHING"... that was a kick in my balls from behind.

So.. know that i explained why i said what i said.. and that you can erify it yourself in the "WIDEBAND READS LEAN ALL THE TIME THREAD"... then im outta hear. I deeply hope you are never wrong.

Sorry for the OF. BYE!

LUDE_4_LIFE
04-25-2011, 05:51 PM
^Hey man. My BOV is open at idle sometimes too, and then under load it will close up. My BOV is a turbo XS RFL so not the greatest BOV out there by any means lol.

I will check the wastegate spring, hope its easy to check...how would i know turbo is fucked? any way to say?

AFR at cruising is rich yes, gone to 9 - 11 from 11.5 to 12.5

No CAT

How do i know its the turbo? how do i check it?

Thank you, but how do i know if the turbo is gone bad...

by the way, this is not the first ebay turbo we using, we have a ebay turbo .63 AR on a 2JZGT single Turbo for a year now...it has done more than 10,000km on that turbo and is still running...i am saying that 2jz because its been with us for long, other than that we have installed ebay turbo's on many other cars...maybe my luck but how do i check?

Not just your luck man. It happens, and happens on a lot of cars. I have seen it first hand several times, and heard about even more failures over the past few years. They are junk, and cheap for a reason.

Back on topic. If the car is running really rich now, you could have an injector failure. If the bearing assembly is fucked on the turbo, the turbo cannot spin fast enough to let the exhaust gases escape, thus not spooling and acting like a clogged CAT.

The last thing is to do a leak down and compression test, because you could have destroyed your engine.

hjdanzi
04-25-2011, 06:00 PM
^Hey man. My BOV is open at idle sometimes too, and then under load it will close up. My BOV is a turbo XS RFL so not the greatest BOV out there by any means lol.


Maybe you are right, what pisses me off is his attitude.. to cry out loud something to make me look like an idiot... Even the op, knows that im the most humble person in this forum... his comment was totally unecesary.

viper_boy403
04-25-2011, 06:15 PM
Chill out amigo. You said I was wrong, and I'm not. I was just pointing that out.

LOL at saying "Everyone knows I'm the most humble person on the forum" That statement contradicts itself so bad it makes me laugh

Now, enough bickering and lets figure out what's wrong with this guy's car

g-gameslude
04-25-2011, 07:44 PM
try adjusting your bov.

rivalbro
07-11-2011, 01:54 AM
Right guys, a bit late, had a lot of family problems, my father had bilateral stroke, his movements and all stopped. he was in the hospital for 2 months and now we brought him back home.
Please pray for his recovery.

updates on the lude, we took it to a friend who knows turbos...he checked it we found one charge pipe leaking so that resolved charging issue...the second issue with WOT was clutch slip. ordered a stage 3 clutch with 12lbs flywheel. waiting for estimated arrival on 25 and estimated installation on 27th july.

will be keepin on touch...

hjdanzi
07-11-2011, 06:53 AM
Im very sad about your father. I knew a guy whose father ha the same, and some months later he recovered and gained back his movements. Good luck man and i hope all ends up good and quick.

98vtec
07-11-2011, 08:44 PM
I have had plenty of BOV's open at idle. as long as it closes under no vacuum and boost loads, then opens properly when you let off the throttle, it is doing its job.

the only point of a BOV is to bypass the still charged air in the intake charge piping.

rivalbro
07-12-2011, 11:59 PM
Thank you hjdanzi...

blake, the BOV till now is working fine and as it is suppose to...i am not going to be too worried about my turbo parts breaking apart, as i have taken that risk into consideration before buying an ebay turbo kit.
By the way, our Ebay turbo kit on 2jz gte (single turbo) last checked was intact till 2 weeks back (after 2 years), the turbo fan broke and came out...it held for 2 years and more than 5000km and more than 20 drag races and 200+kmph speed...bov, wastegate and intercooler still intact...just for information

bb4arson
07-13-2011, 03:54 PM
hope your father recovers bro ,must be hard seeing him like this..

and does your car sounds all sick with a slipping clutch? like if its breaking traction lol

rivalbro
07-16-2011, 04:26 AM
hope your father recovers bro ,must be hard seeing him like this..

and does your car sounds all sick with a slipping clutch? like if its breaking traction lol

i seriously have been thinking about what kind of sick sounds you would be talking about but no clues man...it just goes free and when accelarator is depressed it comes to normal function

accordludeH22
07-24-2011, 02:31 PM
Hey bro good luck on your car. Hopefully you will get it going good. I have a friend with a turbo EG and he had something simular happen. we did a boost leak test and found a small hair line crack in his fmic. It was crazy that little crack caused him to loose boost. Got it fixed and its running great.