I have a LS turbo.

The other day, I backfired big time.

2 days later, by BOV isn't going off and I can't rev past 5500
and my car is weak as hell.

I'm going to try a new BOV today, but I doubt that's the problem.
The Turbo is still boosting at 2500 rpm.

My car just feels super weak. I'm susupecting its the valves.

Can anyone help me out. I did the research on the forums with
people having similar problems, but they had VTEC problems.


Please help....running out of Ideas.


Modified by masterasia at 1:31 AM 9/21/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by masterasia &raquo;</TD></TR><TR><TD CLASS="quote">I have a LS turbo.

The other day, I backfired big time.

2 days later, by BOV isn't going off and I can't rev past 5500.

I'm going to try a new BOV today, but I doubt that's the problem.
The Turbo is still boosting at 2500 rpm.

My car just feels super weak. I'm susupecting its the valves.

Can anyone help me out. I did the research on the forums with
people having similar problems, but they had VTEC problems.


Please help....running out of Ideas.</TD></TR></TABLE>


have you done a compression test?

 

i know u said backfire but, just to make sure, did it feel like when it happened the car felt likethe gas shut off for a quick second? is the car tuned? what kind of fuel management and fuel upgrades do you have on the turboed car. look into that also. was once a problem of mine. car wasn't getting enough fuel in the higher rpm's. good luck. sucks to have a turbo and can't kick any butt

 

I have in my car...

Walbro 255 fuel pump
AEM Fuel Rail
450cc DSM injectors
B&M Fuel Regulator
Blitz BOV
T3/T4 Turbo intercooled
2.5 Downpipe
TiAl 38mm Wastegate

I'm using AFC for fuel management


I've heard about the SafeMode/Limp Mode.
I already Reseted my ecu, but I didn't check the codes yet.
I'm waiting for my friend to bring his Code Reader over.

When I backfired, my engine was totally flooded.
I pulled over and turned off my engine for a few seconds and it restarted fine.
It ran good for about 2 days, then when I was on the high way, I boosted one final time and the BOV went off, and in a split second, my car was running shitting as hell. I didn't find out about the safe mode until I reved it in neutral later and couldn't get past 5500. It's as like the fuel will cut off if I try to hold it there.
This sucks. I need turbo boost.

I'm thinking it might be my Cat. When your car is in safe mode, you have to fix
what ever is wrong to make it get out of safe mode right???

 

i had that same problem. Sorry to say this but when i did that i melted my piston to my sleeve had to get new je pistons. Your problem is not good Good luck

 

what did of boost control? what kind of gas you run?

 

try checkin your intercooler piping (intake side)...did it come loose?

 

I checked all my pipes.....the car still boost......just no BOV....
I'll know more when I do a diagnostic later today.


I only run 92+ octane on my car. I don't think it was a piston. The car
sounds and runs fine, just can't rev past 5500.

 

Did some more tests.....

my compression on all cylinder was 90 psi.
It think cylinder 4 is not firing.

Anyone think it might be the valves????

How much does a valve adjustment cost???

 

The fact that it is not blowing off, means either the BOV is fucked or, it is not getting a vacuum signal from the intake manifold, which lets the valve open to relieve the surging pressure from the still spinning turbo.

Maybe for some reason it backfired through the intake...I don't know...but for some reason you're not seeing vacuum, or your BOV is crapped out. Does it idle ok??? I guess the valves being screwed up could lower the intake manifold vacuum pressure. Maybe a gasket somewhere???

As for the ECU not letting it revv past 5500, I have no idea. I guess pull the code, and check that out. Maybe if you reset it, it'll go out of limp mode, and not immediately go back in.

Anyone else got any ideas...that's kind of sketchy

 

is there oil in the coolant or vice versa? could be a headgasket, or a ringland or two could be broken

 

Here's what I checked so far....

ECU codes...found nothing
my idle is okay...boost gauge reads -20 at idle, which means I'm it's not Vacuum
Compression Test all at 90 psi
Changed all spark plugs...found that cylinder 4 wasn't firing
Took off my turbo...so I'm running N/A
Still can't rev past 5500.....Car is so weak right now

Going to do valve adjustment next...

 

Maybe you have a weak spark and it's time to change the distributor and the plug wires. If you can't spark the mixture, then you can't spool the turbo. The fact that you're backfiring and cylinder 4 is not firing means it's gotta be an ignition problem.

 

What would explain the low compression....????
90 PSI - 120 PSI is very low...LS motors shold be around 170 PSI

When I had my turbo still on, it still spooled. The problem is
that the motor doesn't want the air. My car feels like its sucking in
air and blowing it right back out without mixing it fuel.

I have new NGK spark plug wires in and new Denso Iridium spark plugs.

Would the intake manifold have anything to do with it? The throttle body
feels like it's still powerful sucking in air. I put my hand over it and it almost
sucked it into the motor.

Is it possible that the valves are letting air through?

I don't see any fuel in my oil so I don't think I blew a piston or valve.


I'm running super rich right now. I'm getting like 12 miles to the gallon.
I have an AFC to lean it out, but it's still running rich.

When I hit the throttle, I can see my A/F gauge go right over to Rich.
It seems the fuel I'm putting is not burning at all.

My car revs up to close to 3000 without any problems when in gear, but it takes forever to rev past that. I have to torque what so ever. I can still drive on the freeway, but it takes me forever to get up to speed. The motor sounds fine to me when it idles...just that it is too damn weak right now.

Somebody please help...I don't have the time right now to do a motor swap...
just too damn busy....

Modified by masterasia at 1:28 AM 9/21/2005


Modified by masterasia at 1:29 AM 9/21/2005

 

Somebody please help

 

When i melted a pistion it sound fine but had problems reving up.. you said you were having problems with four.. it seems to me what it is and i would stop driving it you are only making more worse for yourself

 

After I replaced the spark plugs, cylinder 4 starting firing again.

I think its my timing. There's too much fuel when I rev and it's flooding
the motor. Anyone else thinks different?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by masterasia &raquo;</TD></TR><TR><TD CLASS="quote">After I replaced the spark plugs, cylinder 4 starting firing again.

I think its my timing. There's too much fuel when I rev and it's flooding
the motor. Anyone else thinks different?</TD></TR></TABLE>


did you check the timing?

 

is it tuned properly?

 

igniter (sp?) on the distributor?

 

Are you doing your compression test the right way? Cuz if you really have 90 psi on all 4 cylinders you're screwed

 

I checked the timing, distributor, oil pressure, and compression

Everything seems fine.


My car still won't rev over 5500. It lost a lot of power. It has no torque at all.
I took off my turbo and leaned out my fuel. Up to 3000 rpm, it runs like stock, but past that it shitty.

I did some research and found people with similar problems, but they never
posted the solution.


I do have some codes from my ecu relating to my automatic tranny.

When I did the conversion from auto to manual a while back, I used my
auto ecu and wire harness. It worked fine. I just got 4 codes because the
ecu wasn't seeing my auto tranny. If the ecu didn't like it, it would have done something back then, right?


Everyone I ask says to swap out the harness and ECU.

 

did u check all your charge pipes to see if any blew off, that happend to a buddy of mine and his car was slower then dog ****

 

That was the first thing I checked.

I checked all the pipes and intercooler. They were fine.

Right now I have my turbo off. I'm running N/A

 

bump for a solution....