Shaking under boost

[CSquared]

Well after posting this in informational like an ass... here is a second attempt.

Well i went to alabama this weekend for supra shootout. On the way i had a plethera of problems, which is wierd considering this car has been reliable for so long at this point. (made thousand mile trips back and fourth from New York and Georgia just a month ago)

I was in 5th gear at 80mph(3000rpm) and hit the throttle to pass a car in front of me... Instead of passing my car decided that it wanted to offer no power and shake violently as if i was running over those things on the side of the highway that tell you when you're going off.

So it seems that every time i boost the car does the same crap... Shakes and goes nowhere. Other suggestions have been my plugs... bad fuel... and faulty egr valve. I was thinking boost leak originally.

Other information: We were sticking my car on a trailor but it turned out that the incline was too steap. For the first time in my life i burnt my clutch. We let it sit about 5 minutes while running... turned it off for about the same amount of time... and left. I think i may have hit my intercooler but we found no visual abrasions(spelling?) Car was fine for about a half hour even under boost then it started crapping out on me.

We pulled off, had a meeting of the minds, and capped the vaccume line to the egr valve and it stopped shaking for a while... was still low on power but not shaking. Then... after I'd say anothing 15 min it started again.

SUGGESTIONS?

 

[CSquared]

Just to add... I did some city driving today and there is some hesitation/missing during all acceleration(with and without boost)... Obviously though as i said it's more prodominant during boost.

BONE STOCK

 

[doom26464]

mine did the exact same thing. Change your spark plugs. If its not that most likly boost leak but im almost sure its spark plugs. Mine were fouled really bad and it did the exact same thing.

 

[mkiii222]

I had the same problem with bad gas, which led to fouled plugs. If it is bad gas, get some cheapo plugs to run because they'll just foul out again within a week.

 

[lagged]

boooooooost leak.

 

[CSquared]

lol it's something different to everyone... I hadn't really had a chance to look at the car but actually i just found a nice pool of oil surrounding my first spark plug. About to pull the rest later when i get back from school.

Sound like my problem/solution?

 

[mkiii222]

That would probably be your problem. May have fouled the plug, or you may be able to clean it up and be good to go. Just be sure to find the source of the oil(bad ring, valve cover gaskets...).

 

[CSquared]

My valve covers leak oil and i guess it's been a while since i checked how tight they were. I'm off to the hardware store after school to see what i can find in the way of new bolts. The gaskets themselves are in the car about 12,000 miles. Replaced all of that hardware when the headgasket went.

You'll hear from me later if that doesnt work. Also I'm about on E at this point... so we'll also see if it was the gas.

 

[mkIIIman089]

Just to reinforce what everyone has said. I also think that it is either a boost leak or fouled plugs. Though I have never delt with oil between the valve covers personally before that could be a problem with the plugs I suppose.

 

[MDCmotorsports]

BOOOOOOOSSSSSSSSSSSTTTTTTTTTTT LEAK.

Check the plugs too.

 

[Disco Stu]

Get stock NGK or Autolite coppers. Won't be more than 15 bucks. Get some starter fluid while you're there to check for a boost leak if the plugs don't fix it. Valve cover bolts from an Acura Legend V6 happen to work very well and look sweet. You could pay for them or maybe not, your call.

 

[mkiiSupraMan18]

mine did this once...... has never done it since.... friggin 7mgte.... :icon_conf

 

[lagged]

did you check for error codes? i bet youll find a code 34.

 

[CSquared]

Code 34 is turbo pressure? Which would mean boost leak?

I'm not getting any check engine lights and unfortunately i dont have any diagnostic tools. See if i can get them read tomorrow.

I just replaced my plugs tonight and have ngk wires with maybe 12,000 on them. It's not bad gas as everyone was saying since that has been adressed. Still doing this crap. Doesnt really happen in lower gears although they feel rough(like theyre about to break up). It really happens when i try comfort driving such as boosting from 3000 rpm in 4th gear. Also... doesnt really start until i get around 7-ish pounds.(or so it seems)

You are the man btw... every time i have a problem you are usually the one that sends me in the right direction.

 

[lagged]

well hopefully youll figure it out.

look, you dont need any "tools" to check error codes on our cars. see the TSRM for the way to get the error codes.

hitting fuel cut will throw code 34, the light will go on and NOT stay on.

if it is a violent cutting on and off of the engine while you have your foot on the pedal then its almost certainly fuel cut which can be cause either by excess boost, or a boost leak.

check ALL your IC pipes, and dont forget the one from the 3000 pipe to the TB.

 

[CSquared]

well hopefully youll figure it out.

look, you dont need any "tools" to check error codes on our cars. see the TSRM for the way to get the error codes.

hitting fuel cut will throw code 34, the light will go on and NOT stay on.

if it is a violent cutting on and off of the engine while you have your foot on the pedal then its almost certainly fuel cut which can be cause either by excess boost, or a boost leak.

check ALL your IC pipes, and dont forget the one from the 3000 pipe to the TB.

lol well i feel like an ass but i guess you learn something new every day. I'm pretty sure i can fish around the office and find one of those expensive diagnostic paper clips. I'll let you know how it goes.

 

[CSquared]

Ok according to the process given by the tsrm I'm not throwing any codes. I got home, turned the car off but left it in the acc position... Cut a section off of one of those garden flags on the thick metal wire and set it up as shown in the illustration

No spaces between blinks... Just kept going.

EDIT: I went through all of my intercooler piping with a fine tooth comb and found nothing. The intercooler although dented at the bottom is fine. The only thing i can think is the acordian hose to the turbo is a little frayed on the turbo side but not past the outlet. i doubt that is the problem, but I guess i'll replace and go from there.

thanks

 

[mkiii222]

If you've taken care of plugs, know it's not the gas, and have cleared up the oil, then it's probably boost leak.

The pipe from the turbo to the intercooler is easy to miss(it's the one mine was), as is the hose inside the front bumper.

 

[CSquared]

bump for edit on my last post.

 

[lagged]

well if you didnt get any codes then you didnt hit fuel cut. at the moment nothing is coming to mind so someone else will have to chime in.