My car normally boosts to 1.5 bar...

One day I was driving, coming out of a turn on second, car felt like it did not boost up to 1.5, like something was blocked, then when I put more throttle to it, the car kind of jerked really hard, like i took off my foot from 100% throttle and placed it back again (all the while, my foot was on 100% throttle). slowed down a bit, and then gunned it again, and everything was normal. Thought is was just a hiccup...

Sent it in to the shop to change the clutch, and when I got it back to test it. It did the very same thing, on the first attempt. And then, the whole time I was driving the car, it would only boost up to 1.3 bar....and if I kept on going till redline, the engine would cut off and get back on again...it feels like, I am hitting some kind of limiter, or the car protecting itself. Since I was not boosting as much, I was also running rich, and I heard back fire also.

Brought it back to the shop, and the guy test drove it said ti seemed normal, and boosting consistently at 1.2 bar!!!! argh! Had him check tha vaccum line, and they said everything seems normal!

What could be going on? help please!

 

what mods do you have done? are you tuned?

 

Boost leak? Are your IC pipes tight? Any CEL?

 

Sounds like you may have a leak.I had a leak on my car and even though the boost gauge read about 1.4 bar I knew it did not feel like it was.I checked and one of the intercooler piping hoses had a rip and that was causing my boost leak.

 

boost leak test.

 

Check your LICP... my evo was lowered and one day it somehow had a very small "slit" into it, and when i hit full boost, only sometimes, it would feel like the car would "bog" a bit... then sometimes catch fully. If not, run a boost leak test honestly

 

+1

 

I am on my way to the shop now to do a boost leak test....

The car is slightly mod, it has HKS exhaust, and Stage 5 headworks, drop in filter, and tuned via SAFC only...all else are stock.

 

check your spark plugs too...they may need to be changed but it also sounds like a boost leak as well

 

definitely a boost leak. there's muuuuuuuch more to check than just vacuum line. good luck.

 

checked everything already, and there seems to be no boost leak...test drove the car again, and it is not only boosting up to 1 bar....any other ideas?

 

Also, when I was test driving the car...if I held partial throttle at say 4,000 RPM, to try and keep it there...the car starts to sound like it has a machine gun in the exhaust...Sounds like the Rally cars right in the starting line when they throttle up...but not in a good way.

Anybody have a clue?

 

last time my car did that i had jumped timing.... had to change a few valves....

 

what all should you check when doing a boost leak test?