fg won't boost

[blacktur8oute]

Hi all

fg xr6t won't boost it revs to about 4000rpm and won't rev any more and then when I back off I hear a gush of air coming out, it was tuned about a year ago on 98 and E85 ran perfect up until few weeks ago has the following mods

6235 precision 

turbosmart accuator

twin 460 walbro's in PW serge

PW fuel rail turbosmart reg

ID 1000 injectors

PW race box & cooler

4 Inch xforce

ive done a bit of research on here and tried a number of things with no luck, I've repealed & checked

all 6 coils replaced

new genuine plugs gapped at .8

boost solenoid replaced

ive checked all plumbing joins and hoses all good

I removed the dump pipe to see if the flapper is moving freely with blowing air in the accuator and all good

replaced fuel filter 

with all of the above still no luck is there any suggestions on what it could be or what else to check for before I take it to the tuner

[Panda Eyes]

cooler hoses, but you already did that. 

I would take a visit to your tuner before any thing else.

Edited 04/09/17 02:03 AM by Panda Eyes

[Ralph Wiggum]

Are you missing any rubber gloves?

[blacktur8oute]

Rubber gloves ?

[k31th]

it's a joke reference to this thread

[4321]

Undo the outlet pipe from the turbo. find a old inner tube & cut out the valve stem with enough of the rubber to clamp around the outlet pipe, put your compressor on to the valve stem & presurize the inter cooler & piping system ( I use about 30 psi) & listen for air leaks It should hold most of the pressure If it pass's this test look at the turbo.

[blacktur8oute]

Thanks will try it

 

What's to check on the turbo both vacuum lines from the boost solinoid to the turbo and accuator are good no play in the turbo all tight it's done about 2000km

[4321]

The actuator should hold the waste gate shut, assuming it's a 12 psi actuator it should take 12 psi down the vac hose to force the waste gate open bypassing the exhaust gas from the turbine & therefore stopping the turbine from spinning fast enough to make decent boost. Check that the actuator is fully up (you might have to measure another one) to check weather the waste gate is shut. If you unbolt the dump pipe you can see in there. But my bet its the rubber hose on the t/body

[blacktur8oute]

It's not the throttle body hose I'm running a silicon one, I've pressureised the plumbing as you said holds pressure, I removed the dump pipe again and the gate was closed I put 12psi as you said and it was opening and closing freely

[Puffwagon]

On 04/09/2017 at 11:18 AM, blacktur8oute said:

it revs to about 4000rpm and won't rev any more

 

Open wastegates and busted intake fittings won't cause this. A turbo car can still rev to the limiter with a huge hole in the piping and can still make boost with an open wastegate although it wont make any until about 3k to 4k rpm.

 

At any rate the car will need to be plugged into a scanner/tuner and checked to see what is happening.