No boost under load

[Elek_ron_ix]

I have a 1995 Eagle talon TSI and it will not boost over 2 psi. I just had to change my headgasket and pretty much redid the whole top end of the car with OEM new parts. I did the 100,000 mile stuff since i had the head off. I did notice when I manually hit the throttle from the cable control the wastegate actuator arm doesn't move. I'm thinking the wastegate is stuck. My BOV doesn't seem to be working either. The car seems to be running fine, but it's slow now. Any help on my problem would be much appreciated. Thanks, Ron.

 

[RadDsm]

Check to make sure the flapped is still connected to the wastegate arm, and a boost leak test never hurts.

 

[SmoochDarling]

In this order:
-Check WG flapper arm,
-remove arm and manually move WG flapper to see if it is indeed stuck.
-Boost leak test
-Fix all boost leaks
-Compression test
-Set base timing
-Check plugs/wires

Still problems?
Check mechanical timing.

You could have a few problems here,
-The car not building boost because of a large leak
-No boost because WG is held open
-No boost because the ign timing is off causing sputtering and bogging down
-No boost because your a mechanical timing is off
-If none of these, you could be running really rich causing super bogging issues

 

[Jerkychew]

My fuel pump strainer was clogged and I had a similar issue.

 

[miguelmcv]

If he is saying the car is working good, except boost.
I think all what he have is a WG Problem.

Try to disconnect the WG Hose, and give a drive to see how it works, It should build boost.
Put some air pressure to the WG, and see If it opens and closes freely.

By the way.
How is your set up?.
Insert some pics to see how the set up is (WG source line).

Ho, I just saw that you have an AEM electric Boost Controller.
Run the vacuum line jumping the boost controller (run the vacuum line from the turbo to the WG), take a drive and see if it build boost.

Your Boost Controller might be OFF.

 

[Elek_ron_ix]

Okay took it for a spin after rerouting tubing and found a vacuum hose off coming from the EGR. On my test drive after I got to six PSI max. BOV works fine also.After my boost leak check tomorrow I will see if there is a leak I can fix to close the system. Will post results tomorrow evening. Thanks for everyones posts.

Does anyone know offthe top of there head the sping pressure rating for a T3/T4 turbo wastegate? It's the internal that came with the bullseye turbo.

miguelmcv : Thanks for the good info. I have the settings on the electric boost controller turned down since I'm not sure what settings were set to by my by last tuner. I'm trying to figure it out tho. It's definitely on setting A not B which was my track setting. Which somehow saved and my everyday driving one got reset, so I have to find a baseline for now to get around on until I save some money. I will post pictures tomorrow of under the hood of the wastegate area.

 

[caseyk]

Okay took it for a spin after rerouting tubing and found a vacuum hose off coming from the EGR. On my test drive after I got to six PSI max. BOV works fine also.After my boost leak check tomorrow I will see if there is a leak I can fix to close the system. Will post results tomorrow evening. Thanks for everyones posts.

Does anyone know offthe top of there head the sping pressure rating for a T3/T4 turbo wastegate? It's the internal that came with the bullseye turbo.

miguelmcv : Thanks for the good info. I have the settings on the electric boost controller turned down since I'm not sure what settings were set to by my by last tuner. I'm trying to figure it out tho. It's definitely on setting A not B which was my track setting. Which somehow saved and my everyday driving one got reset, so I have to find a baseline for now to get around on until I save some money. I will post pictures tomorrow of under the hood of the wastegate area.

I had a bullseye 50 trim with internal gate. I believe mine opened up at around 12psi with no boost controller. Hope this helps.

 

[Dert]

You have 1) a boost leak
2)wastegate stuck open
3) HUGE preturbo exhaust leak
4)failed turbo


Sent from my iPhone using Tapatalk

 

[Elek_ron_ix]

Okay I did my leak down test and to no resolve. I didn't hear or feel any boost leaks. The good news is I boosted 11lbs after putting my old road tune on. It seems to boost really slow tho and late it starts about 3300rpm and peaks at 11PSI at 6100rpm. My idle has improved but seems to stutter a bit not under accelaration, like maybe fuel loss.Any suggestions of why it do this?

Caseyk your dead on it was 12.5 for the spring pressure, thanks!

 

[Dert]

Okay I did my leak down test and to no resolve. I didn't hear or feel any boost leaks. The good news is I boosted 11lbs after putting my old road tune on. It seems to boost really slow tho and late it starts about 3300rpm and peaks at 11PSI at 6100rpm. My idle has improved but seems to stutter a bit not under accelaration, like maybe fuel loss.Any suggestions of why it do this?

Caseyk your dead on it was 12.5 for the spring pressure, thanks!

Try putting dishsoap in a spray bottle and spray all IC couplers, BOV, Throttle body, injectors, BISS screw, when doing boost leak test so you can SEE the leaks. Slow boost build is 98% of the time a boost leak. Stutters can be a number of things, check for fouled, incorrectly gapped plus, bad wires etc. Depending on your tune, you could be easily overrunning your 600cc injectors too, so your not getting the fuel needed. I'm personally almost maxing out my FIC 650's on a 190 wally, and 57 trim with a moderate tune on link.

 

[Elek_ron_ix]

Thanks for the info Dert. I do believe I'm going to replace my fuel injectors next. I got to do some research to see what type I need, but first going to replace the stock fuel pressure regulator with the Weapon R one I purchased. The car is running alot better now tho. Even my lifter knock is gone now after the headgasket replacement. Thanks for everyone's help and keep the helpful information coming.

 

[rEclipserGST]

You said you did a BLT, what boost did it start leaking at? Test up to at least 20 psi. Need to know how much psi, & how long it took to leak out. Use soapy water, & an air compressor. NOT a bike pump.

Pictures help as well, to spot anything you are doing wrong or may be out of place.