not boosting when gauge shows boost

[89turboguy]

As the title says. I built boost, like 1 bar, BUT the car didnt actually boost. so i tryed it again in third gear instead of second and it started to boost but then stopped boosting. I know the turbo is fine because first of all i am running open 3in. dp and i can hear the spool and whistle and it sounds perfectly fine. Also it shows boost fine on my gauge. Any thoughts?

 

[suicide]

where is your boost gage hooked up too... its posible you mihgt have a pluming leek after the gage and its not getting to the engine

 

[MDCmotorsports]

You're going to have to explain - "It builds boost but doesn't boost."

 

[plaaya69]

I would also check the vacuum hose that goes to the boost gauge sensor. It could be loose or have a small leak.

 

[oscolivar1]

i guess he's trying to say ihe see's that the car is boosting from the boost gauge and sounds, but he doesnt feel the response the car should be giving from the readings...

if thats the case u have a boost leak.

 

[amd_hcds]

I'd start with an aftermarket boost gauge

 

[89turboguy]

i guess he's trying to say ihe see's that the car is boosting from the boost gauge and sounds, but he doesnt feel the response the car should be giving from the readings...

if thats the case u have a boost leak.

exactly what he said. i have an aftermarket gauge. it is T'ed right before the stock boost gauge sensor. i guess i will have to check for boost leaks, but if i had a boost leak wouldnt it still read less boost on the gauge?

 

[loki2043]

hmmm. my car did the same thing... i just thought it was slow lol. ive only had the car for about 7 months as a DD for work. but i want to get some juice out of it.. i was always wondering if it was sapposed to be a little faster, and turns out it was sapposed to. so i decided to go with a rebuild so i knew that everything was going to work perfectly. and turns out my exhaust manifold was loose as shit, and the turbo was loose as shit on the mani, and the elbow was loose as shit. when i say loose as shit i dont mean wobbly, just leaking a LOT and not torqued down much.

anywho, the car still built full boost pretty quicky, but no balls, so i never really knew what was wrong... also i was developing RK, but soon she will be good and FAST!

check your exhasut nutz

 

[aye mate]

Check for boost leaks. Don't forget the Throttle Body coupler, that one gets overlooked all the time. I guess it could be the manifold or the turbo is loose, wouldn't hurt to check also.

 

[mkiiSupraMan18]

uhh...

Checked your timing?

 

[MDCmotorsports]

uhh...

Checked your timing?

W3rd.

Check your timing on not only your cams, but your cps.

 

[mkiiSupraMan18]

Another thing I've never understood,

If he has a boost leak, how the heck is he showing a bar? Wouldn't the AFM be all over that w/ fuel cut? Hell mine hit at 6psi when I had my boost leak(s).

*edit*
AFM, ECU, WTFE.

 

[89turboguy]

Thanks guys, i will get all this checked out. My downpipe is loose as shit because i got a full3 inch and the nuts i had wouldnt clear the dp so i only have 2 on there, but it ran fine for at least a week like that. so i dunno.

Mkiiisupraman18...
I am hitting fuel cut at 1.2 bar still, so thats why i wasnt thinking it could be a boost leak. so i dont get that either.

i also have a huge crack in my intake pipe, but yet again it ran fine for a while with that same crack.

 

[s383mmber1]

Thanks guys, i will get all this checked out. My downpipe is loose as shit because i got a full3 inch and the nuts i had wouldnt clear the dp so i only have 2 on there, but it ran fine for at least a week like that. so i dunno.

Mkiiisupraman18...
I am hitting fuel cut at 1.2 bar still, so thats why i wasnt thinking it could be a boost leak. so i dont get that either.

i also have a huge crack in my intake pipe, but yet again it ran fine for a while with that same crack.

That crack could have gotten much larger....

CHECK TIMING!

 

[89turboguy]

how would my timing get changed all of a sudden? wouldnt that make my car run bad and missfire even when im not in boost?

 

[cwapface]

how would your boost gauge measure boost that isn't there?

 

[89turboguy]

I dont know, that is why i made this thread :icon_razz

 

[loki2043]

if your dp is loose then your leaking exhaust. your o2 sensor isn't reading right most likely... maybe running nice and rich?

 

[89turboguy]

id rather be rich than lean. but i doubt that is what this is caused by.

 

[mkiiSupraMan18]

how would my timing get changed all of a sudden? wouldnt that make my car run bad and missfire even when im not in boost?

Maybe the bolt on the tensioner came loose? Belt may have stretched... maybe something magical happened to stop a cam or something and it jumped that way.... I dunno. But seriously it takes 12 seconds to check and can rule out an easily fixable problem.