rough idle and boost gauge lit up in park.

[Tony87gn]

Car has a really rough idle and and my stock boost gauge is lit up in park. Seems like it is running really rich. I drove it to work and it was fine then I go to leave work and this is happening any ideas? Vaccuum leak?

 

[Tony87gn]

ttt

 

[noslo6]

Sounds like you have a vacuum leak and/or your line to the map sensor has come off (which would also be a vacuum leak).

 

[vader87]

I agree since you are showing boost in Park. Also check your Fuel Pressure. Mine idles terrible if it is over 44 pounds. Should be set at 42-43 line off.

 

[unix_punk]

IMHO a vacuum leak wouldn't cause the boost gauge to light up. The way the MAP sensor works for the boost gauge is the voltage increases (on the green wire) as boost increases. So if you were to check the voltage at the green wire coming off the MAP or behind the glove box on the clear/black connector with the key on/engine off you shouldn't see anything close to 5v. Maybe check the voltage coming into the MAP as well (the other 2 wires.) That should be 5v.

Also, a vacuum leak could cause a ruff high idle, but because it causes a lean condition, not rich.

Any logger/gauges that you could tell us their readings?

I agree with vader, I'm sure you've checked all the vacuum lines, but maybe double-check the line off the regulator.

 

[Tony87gn]

ok looked at the car while runing again and I noticed a good sized crack in my downpipe. That would explain why my turbo was so laggy I guess. I can see exhaust fumes spewing out of the crack, would this cause the problems Im having? inserted a picture showing where the crack is. Also i do not have any money to buy a new downpipe is there anyway this could be welded?

 

[unix_punk]

Im not so sure that would effect you much, if at all, since it's after the turbo.

 

[Tony87gn]

im at a loss for what it is then

 

[Tony87gn]

pretty sure all the vaccuum hoses are good. My boost gauge even lights up when I just put the key in the car and turn it without turning the car on, this is really wierd

 

[Underboost]

When my boost gauge on the dash lit up all the way across. It was my map sensor on the passengers fender w/ the vacuum line attached to it. :smile:

 

[Tony87gn]

are you saying that it went bad?

 

[Underboost]

are you saying that it went bad?

Yes

 

[unix_punk]

keep in mind that unless it failed in a way that would cause a vacuum leak, the map sensor going bad would not effect how the car runs because the only purpose of the map sensor on a stock ecm car is for the boost gauge in the dash...

 

[Tony87gn]

Yeah I should have mentioned I have a modified MAP for the MAFT pro system. So it must be the map.

 

[unix_punk]

ah, yes do you run a 2-bar (stock) or 3-bar? I have a 2-bar if you want it.

 

[Tony87gn]

if i remember correctly it is a 3-bar, thanks for the offer though man

 

[bison]

ok looked at the car while runing again and I noticed a good sized crack in my downpipe. That would explain why my turbo was so laggy I guess. I can see exhaust fumes spewing out of the crack, would this cause the problems Im having? inserted a picture showing where the crack is. Also i do not have any money to buy a new downpipe is there anyway this could be welded?

That crack could be welded very cheap. The guy that does all my welding wouldnt charge more than $15 for that if it was off the car.

 

[unix_punk]

if i remember correctly it is a 3-bar, thanks for the offer though man

Not a problem. Let us know how it turns out after you swap that MAP.

 

[Tony87gn]

Thanks bison for the info Ill have that welded then. Do you think it would cause lag though? Hopefully the problem goes away after the map sensor is out.

 

[Tony87gn]

I took another look at the sensor and there is a brown plug that is coming off of it that isnt connected to anything. The sensor is plugged in though. Any idea what it is?