SLOW SPOOL & LOW BOOST ???

[1BADCOBRA]

I am only getting about 8 psi from my VDO aftermarket boost guage and it takes about 10 seconds for it to spool-up to the 8 psi.!
WTF can it be........I heard something about a relay on the firewall that can cause this ?
Could my Turbo be going bad ?

Thanks again.....Frank

 

[kwick6]

Have you set your pre-load on the wastegate arm?

 

[1BADCOBRA]

Have you set your pre-load on the wastegate arm?

I'm assuming its correct , but i'll check it tomorrow. Yes, i have the little chart off this site that shows the proper way to set it up.
Are there relays on the firewall that can stop boost at around 8 psi ?

 

[Divergent Lightning]

if you are still using the Boost control solenoid it might be worth replacing it. It is only about $20 from the General himself.

 

[1BADCOBRA]

if you are still using the Boost control solenoid it might be worth replacing it. It is only about $20 from the General himself.

OK, but won't that cause an over-boost and not a low/slow boost ?

 

[kwick6]

Have you set your pre-load on the wastegate arm?

I'm assuming its correct , but i'll check it tomorrow. Yes, i have the little chart off this site that shows the proper way to set it up.
Are there relays on the firewall that can stop boost at around 8 psi ?

You need to check it. Most trucks are not set right. You'll notice a big difference in spool up.

Then disconnect the electrical connector to the solenoid and see if you get base boost (10psi)

Also, when you have the actuator arm off the wastegate rod, open and close the wastegate and make sure it isn't sticking.

Obviously you'll need to pull the inner fenderwell out to get at it, so leave it out while your doing the testing. Throw some gloves on and test the wastegate while its hot also.

 

[Divergent Lightning]

if you are still using the Boost control solenoid it might be worth replacing it. It is only about $20 from the General himself.

OK, but won't that cause an over-boost and not a low/slow boost ?

If the tube of the solenoid that leaks the pressure is clogged you will see slowly rising boost levels because the pressure wont 'be able to vent as quickly as it should letting the wastegate close all the way to enable good solid boost control.

 

[1BADCOBRA]

qwick6.........OK, thanks i'll do that tomorrow.

D Lightning...........True, I didn't really think of that, you're right and since i work for a Buick dealership i'll get me 1 tomorrow.

Thanks , both of you.

 

[1BADCOBRA]

ok, i got a new boost solenoid and installed it and i correctly set my wastegate actuator rod and i still only have 8 psi and its still slow to boost...
Could my turbo be bad.........i did suck a piece of the plastic crossover air tube into it and it bent 2 of my impeller blades all the way around.???

Please help me to have boost...........lol

 

[GregS]

Just how badly are those blades bent? Pics?