Slow boost problem, help please

[Divergent Lightning]

I have a slow boosting problem. I figure I should start with the free fixes first.

Which way to I adjust the wastegate to make it spool faster?

(It is the waste gate rod that you adjust correct?)

 

[Daryl H]

Unless the wastegate is way loose or you only build low boost
then adjusting the wastegate will only yield a higher peak boost.

What PSI are you able to achieve now?

 

[Divergent Lightning]

It gets all the way up to where I need it to be it just gets there really slowly...

Would the solenoid or actuator be dead?

 

[kwick6]

Hey Clint,

I'd start by making sure the rod is set properly.

following is from chitownsyty.....

The wastegate rod is connected to the wastegate lever. The lever has a pin, the rod slips on to it, and a retaining clip through the wastegate lever holds the arm/lever together. If you pull the pin, and slip the rod off the lever, the hole on the arm and the lever's pin should overlap slightly. In the manual it states to look for 1/2 overlap, so you'd have to pull the arm out of the actuator slightly (tight spring tension here) to connect the arm to the lever's pin. I believe the overlap spec has been updated so factory specs are now 7/8 overlap (basically a looser/longer rod setup). The arm's length can be adjusted as the rod end is threaded onto the rod. Tightening the end will shorten the wastegate, loosening lengthens it. If the rod is shorter, the wastegate is clamped more tightly shut. If the rod is longer, the wastegate is held loosely shut. If the rod is shorter, the actuator requires more boost pressure to open the wastegate the same distance as if it were adjusted longer. Result - more boost, faster spool up, as the wastegate is not opening quite as much, and not as quickly. The opposite goes if you lengthen the rod.

Make sure its set like that, and if your still having problems then it could be other things, but I'd do that first.

 

[Divergent Lightning]

Alright I went and adjusted the wastegate rod. Boost now spools up to where it is supossed to much faster and when I shift, boost only drops to 11 psi instead of 8 or 9. Granted I would like it only to drop to 13 or so but it is a start.

 

[ghettosled]

sure its not pulling out timing on shifts? As a result, this would cause it to pull back boost. Usually it will spike on shifts.

 

[Divergent Lightning]

It is pulling timimg a little bit, I ran DM the other day at the MOFO gathering and only saw 6-7* of knock. Boost was almost half way to where it should be with the signals it was getting. Once the signals topped off at my intended boost level the turbo would spool up the rest of the way...

 

[kwick6]

Have you redone your vacuum lines? Is the boost control solenoid hooked up correctly?

Sounds like your only getting base boost.

 

[Divergent Lightning]

actually come to think of it, every time I accelerate, I hear this somewhat noticable whooshing sound from under the dash in the pedal area. I will have to go check that out. It probably is a loose/ruptured vacuum line. Other than that the engine bay has been redone in silicone vacuum lines.

How many vacuum lines are under the dash?

 

[kwick6]

actually come to think of it, every time I accelerate, I hear this somewhat noticable whooshing sound from under the dash in the pedal area. I will have to go check that out. It probably is a loose/ruptured vacuum line. Other than that the engine bay has been redone in silicone vacuum lines.

How many vacuum lines are under the dash?

I've had the one on the canister in this pic blow off, when I didn't have the check valve in place after redoing the vac lines.

You didn't put a vac line on the port of the boost solenoid that has the metal clips surrounding it did you? That is the vent.

 

[Divergent Lightning]

It could be possible that my fat foot took a part of that connection off.

As for the soleniod, I haven't touched it since tha last owner had it. I will check that out too.

Is the venting portion of the soleniod on the left or right side of the soleniod?

 

[Divergent Lightning]

I checked the vacuum conections next to the throttle pedal and they were both on there tight.

Any other ideas where the vacuum leak could be coming from?

 

[kwick6]

Clint,

Did you set your wastegate rod, like this......

http://boostvalve.com/tech/wg-preload.html

So that you have to pull the rod out of the actuator canister a bit to have it go over the stud on the wastegate arm.

I helped a local guy today, and his was way too loose. When we put the boostvalve on, we couldn't get any more than 10 psi..... turned out the rod needed tightening.

As far as a vacuum leak, do you have the check valve installed at the fire wall for the line that goes inside the truck for the heat/AC controls? If you didn't put that checkvalve on, you'll hear a vacuum leak.

 

[Divergent Lightning]

I tightened the WG so the WG rod needed to pulled out a little bit to fit over the hook up point.

As for the check valve, I haven't checked that yet. I need to do that.

Would a bad solenoid cause this as well? or a bad wastegate actuator? I am wondering about that, because they are probably original and have about 130K miles on them