Car looses all power when boosting...

[jmatyas]

Ive looked through a ton of threads about issues similar to what my car is doing but none that do exactly what mine is doing. Hopefully posting my own thread will help.

OK here we go...

Car runs great at idle. Sitting right about 750 to 800 rpm. Runs great under engine power either under low load or wot. The second the turbo starts to boost on wot or when it hits about 4k rpm on low load it just shudders and dumps as though it hit a massive fuel cut. One of my friends said it feels as though I'm getting sucked backwards... Almost feels like the turbo is choking the engine to the point of where i have much less power than just engine power.

What i have tried so far...
Boost leak test 3 times, new spark plugs and wires, compression checked. The car only had 48k miles on it. I'm stumped.... please help.

Stock turbo setup, Only mods are cold air and a 3" exhaust.

 

[AK Maniak]

You must be out of boost fluid

 

[jmatyas]

wow i must be a noob haha. What is boost fluid and how do i replace/fix....it haha. Not trying to be a smarta** at all i just have no clue what that is.

 

[bigolsackapoo]

wow i must be a noob haha. What is boost fluid and how do i replace/fix....it haha. Not trying to be a smarta** at all i just have no clue what that is.

Lol....
Really?
You haven't heard of it because it isnt real.

 

[jmatyas]

Well duh haha. If there was such a thing we would find a way to tweak it and make it better already.

 

[pullerfan]

what plugs and wires? gap?

 

[97-gst]

today i just got my problem fixed. my problem was it felt like my car was hitting a rev limiter at 5000 rpms, i tried just about everything, and finally we hooked up an obd II to the car. It said that i was getting misfire, so we fixed the problem by redoing all the wiring to the coilpacks.

 

[jmatyas]

Ngk standard. No platinum or anything like that. Bought my wires with the ngks at napa which was the only place out here that sells them. Cant remember the brand of wires are offhand. But its what he was running on his 99 gsx. Gap has been tried at .025 and .028 with no diff. Running at .028 atm.

Also there is no check engine light or anything that pops up when it happens. It might be because i switched out the ecu for a eprom if that could happen ( don't know much about ecu's to be honest). And yes i switched the wires for the new ecu

 

[pullerfan]

well you could try putting the old ecu in and see if that fixes it. thats probably the first step i would take. i had this same problem at one point to. i think my problem was that i disconnected the battery and it may have messed up my ecu, after about a day it fixed its self.

 

[jmatyas]

Hate to say already tried the old one again and i had to take that one out in the first place because it had a bad issue and wouldn't work anymore. I remembered that after i put it back in. Also Ive had the eprom ecu in there for quite a while and this problem is fairly new. Ive owned this car for 2 years now and Ive only put about 400 miles on it because of issue after issue. I love my dsm

 

[Dsm4lyfe12]

What bov do you have? Even though in boost leak tests 2g bovs really dont show up, but they do. take my word for it.check your timing belt and your turbine in your turbo, along with shaft play ect. good luck. Hope that helps!

 

[jmatyas]

Thanks man. Ill have my timing checked asap. Hopefully its not too bad. I still have the stock pos bov that came with the car. Ive been wanting to put on a new one but i didn't want to till i got my punishment racing fmic when i can afford it. But if i have to soon i guess i have to.


Also note: The other day i was driving and the boost gauge went all the way down to the lowest vacuum possible. Ive seen it go low but it touched the bottom of the gauge. Also got a small turbo spike once since this started. I forgot to add this earlier sorry, its been a long day.

 

[92EagleAWD]

Sounds like a fuel pressure issue. Check out your fuel pump. ive seen this exact same thing happen to 2 dsms, and it was the fuel pump both times. Next time you pull your plugs check them and see if they are White, Brown , Or black

 

[jmatyas]

Ive been wanting to switch to a Walbro anyways. So maybe now is a better time than ever. But should i go 190 or the 255. I only hope to get max 350hp out of this car. Just a fun street car no racing except a car or two on the freeway on ramp .

 

[GSXSixteenG]

I believe you have to change the plug order using a eprom in a non-eprom 95+ car. I also think the cas is different between a 95 and 95+.

I have dsmlink so it wasn't as much as a concern for me. But I know when using that you atleast have to change plug order and check a box. Maybe a wiseman will chime in.

 

[jmatyas]

Yea i switched the order when i first installed the eprom. I found that out on here after it wouldn't start. Idk what i would do without dsmtuners

Ok so i drove home today and the second the turbo boost started to fill my car died. It chocked it so bad that it just shutoff. Started it back up and made it home. Popped the hood and was able to hit 7k rpm at full boost under no load. Under load it just chokes the engine to the point of it sputtering. Im so lost on whats wrong. Ran a obd2 for the hell of it and it showed not a single code...wtf

 

[AK Maniak]

Definitely sounds like a fuel problem. Try what 92EagleAWD said, should shed some insight

 

[EclipticalGS]

It just looses all ze powa

 

[Boostdclips99]

I had the same problem before. Turned out to be a bad fuel pump. Check all of your connections first then if it still stumbles I would look into a new one. Your eventually going to need one at some point.

 

[jmatyas]

Looks like i have a walbro 255w on its way, checked out my pos stock 2g bov and realized that its leaking, so i went ahead and ordered the punishment racing fmic in flat black with bov inc, love the new color guys! Thanks for all of the help on here and ill let you know if it fixes anything in the next week or two. Thanks again!

Also i went and pulled off the intake to check my turbo play and i noticed i had a bit of forward and back play but no up and down, guessing my turbo is about to go i need to decide to go 16g or more, only want to do about 350hp if that.

 

[highlandgst]

Well if it is none of these problems .. I had the exact issue awhile back ., Under boost my car would bogg and putter bad . I did everything you did so far With the addition of two things I changed out my TPS throttle position sensor because it wasn't working right then I took my throttle body out cleaned the hell out of it because it was dirty as #### after that it ran like a ####in champ

 

[jmatyas]

Thanks for the idea about the throttle body. Ill have to take a look and clean that.

 

[Project_4g63]

16g will be plenty for 350 hp. you can use the stock injectors too. also with a walbro 255 you will need a fuel pressure regulator. Aeromotive make a good one.

 

[standard235]

Stock injectors for 350?

I guess if you bump the base pressure then you could... but i maxed my 450s on 10psi with stock fpr and 255

 

[jmatyas]

I have a ebay (obx or whatever) fpr that i got a for about $40 a few months ago with gauge on it that i hope will be ok haha. I would of went with something much better but i cant afford much with this economy.