boost has been acting wierd??

[doom26464]

Well anyways before I start to get to my problem I will start one of my angery raves. Anyways it was the night of the show and shine car show in our town the other night and some nice cars where out so some guys I met on a forum from like the next city over where down. So we go out to the highway to race and its me (my 1990 turbo supra :love: ), a 89 Turbo honda CRX, Brand new Cobalt SS, And a modded up eagle talon TSI. SO as soon as we get out there it and just about to race it just starts to pour like there no tommrow and we probaly get the worst thunder storm ever. I was really looking forward to testing out my car against these guys.


SO anyways thats just a story to lighten the mood my real problem is latly my boost has been acting so wierd. Usally when I floor it in liek 3rd or 2nd gear it would just boost right up to just 8 and then go and hold it slef at 7 psi and everything be fine. But now when I floor it the boost guage maxes its self out and the car seems to shake and kick kinda of. And its not that smooth sorta of power that u would normaly feel. I though wow my car seems to have found a way to boost pass 8psi but it like shaking and kicking violently. And really Even though for some random reason that it started doing this even though the boost maxes out its not any faster becuase the car is shaking and kicking violently. And also it only does this sometimes. Sometime I will be driving and it will act normal and it will boost like it usually does. SO what the fuck is goign on here???? IS my turbo shot or what? becuses I don't think it should be shot if sometime it acts good and sometimes acts wierd. I recently wraped some of my intake and pcv pipes in heat reflective tape and after it started doing this mabye the heat reflective tape is fucking it up??(even though I doubt that and that mabye its just a concidence) Some one plz help me :wtc:

 

[Stanzaspeed]

does your check engine light come on when the car is shaking violently? if so its probably fuel cut. if thats what it is i would maby check the vac line running to your waste gate for leaks or just out right replace it with some new stuff from an auto parts store. im not sure what else it could be at the moment. thats the best i can do with the info.. hope that helps ya brett!

 

[doom26464]

just checked and tighten all my clamps then took it for a test drive. Its raining outside so I can only boost in like 4th or 5ht with out spinning out. It boosted fine though for like the first 5 min then after awhile it did a little bit of shaking but very very little could have just been the bumps in the road or something else. Though it never did any crazy 8+ psi boosting so thats good at least. Need to do some more testing when it dry up outside.

 

[CTsupra]

You hit fuel/spark/boost, whatever cut . Yeah, it sucks. You Canadians have that nice cold air up there, so you might boost spike more frequently year round.

 

[doom26464]

You hit fuel/spark/boost, whatever cut . Yeah, it sucks. You Canadians have that nice cold air up there, so you might boost spike more frequently year round.

I don't think its fuel cut as Im pretty close to stock only have 3 inch downpipe and drop in air filter. And it how hard it shakes depends one how much boost its going. Shouldn't fuel cut only work if u have major amount of boost?

 

[CTsupra]

Yeah, but you said it shook violenty over 8psi. As we all know, the stock boost guage only goes up to 8psi, so who knows what it might have spiked too.

The only time my 89' shook or bucked violently was when it actually did hit fuel cut in the range of 10-12psi. When this happens, it feels like the car loses all of its power. The engine light will blink on, and then off, then stay on. I would have to turn down the evc-ez, and then boost it up again under fuel cut, so the engine light would turn off. After this the car would be fine, and back to normal power.

My car never shook for a boost leak or anything, and I did have a few. Maybe it's something in your front-end? Steering?

 

[Stanzaspeed]

same here. except i was hitting fuel cut because of a boost leak. it scared the shit out of me when it first happened. maby just outright replace the line and clamps going to the WG.

 

[doom26464]

any other ideas besides fuel cut???

 

[lagged]

premature boost cut. check your IC pipes. you probably have a boost leak some where, causing the premature boost cut.

 

[aye mate]

:withstupi
Check the 3000 pipe > TB. That thing almost was blown in 2 pieces when I finally found out thats what was leaking.

 

[doom26464]

i noticed today one of my houses was loses I tightned it and its been acting good again. IT felt good again to feel the strong smooth pull of the turbo. I don't know the name of the hoses but I can point it out in this pic. This is a pic of my N/a engine bay but it has the same hoses as my turbo the pink sorta of hose that goes all around the engine bay it was lose by the power steering container. What does this hose do anyways??

 

[lagged]

its the vacuum line for the charcole canister.

 

[doom26464]

its the vacuum line for the charcole canister.

???

 

[doom26464]

Well today I took it for a drive and well it was acting up again.... Guess I didn't fix it wonder why it just Acts like that whenever it feels like it....