Won't build boost

[monkeyy337]

Vehicle in question is a 87 Gn and the motor won't build boost. It has vacuum and when you bring the RPM up the vacumm goes down but the motor won't build boost even though you can hear the turbo wind up. We changed the boost selenoid thinking that might be the problem but still have the same problem. The motor has an after market 63 turbo on it.

 

[JW87T]

One thing is the waste gate puck may not be closing on the waste gate hole in the turbo housing. Whenever I change turbos, I have to make sure the waste gate is closing all the way. Usually it doesn't and I have to loosen the down pipe bolts and move it around until it feels like it is closing all the way. Just having it open a small amount will kill boost.

 

[QUIP'6']

Vehicle in question is a 87 Gn and the motor won't build boost. It has vacuum and when you bring the RPM up the vacumm goes down but the motor won't build boost even though you can hear the turbo wind up. We changed the boost selenoid thinking that might be the problem but still have the same problem. The motor has an after market 63 turbo on it.

did this just start with the 63 if so what converter do you have you need at least a 10 inch 3200 to even spool that turbo. does it have a stock elbo on it or a thdp the puck may be fall in the hole if it is a ported wastegate hole.

 

[TurboDave]

You're not trying to do this in park/neutral are you?

 

[mikestertwo]

You're not trying to do this in park/neutral are you?

That's what I was wondering

 

[monkeyy337]

Just to answer a few of the questions asked.
1. The waste gate puck is closing all the way into the waste gate hole.
2. The transmission has a 10" 3200 convertor (or looser)
3. The turbo has an aftermarket elbo which is not ported
4. Were not trying to spool in park/neutral
The vehicle was purchased with the motor laying in the trunk. We rebuilt the motor, put it back together, and the motor runs fine and will wind up with no misses or stumbles but the boost never comes in. Could the turbo be the problem? Thanks

 

[QUIP'6']

Just to answer a few of the questions asked.
1. The waste gate puck is closing all the way into the waste gate hole.
2. The transmission has a 10" 3200 convertor (or looser)
3. The turbo has an aftermarket elbo which is not ported
4. Were not trying to spool in park/neutral
The vehicle was purchased with the motor laying in the trunk. We rebuilt the motor, put it back together, and the motor runs fine and will wind up with no misses or stumbles but the boost never comes in. Could the turbo be the problem? Thanks

i meant is the wastegate hole ported not the exhaust elbow. and the wastegate puck should be closing on the hole not in the hole if it is going in the hole the you need a bigger diameter puck

 

[BlackBandit]

How are you measuring boost? Assuming the device being used works can you be a little more specific? By no boost do you mean none, not even 1 pound? If so I would check to make sure the wastegate puck is covering the hole. The rod should put some tension on it even when it's closed. If this is the case you can try unhooking the line from the wastegate and trying to spool it SOME. This will tell you for sure whether the problem is the puck/hole or the control devices. I can't stress enough that you need to be careful doing this and also need to be sure the device measuring boost works before you try it. If it doesn't and you don't think you have boost and you keep trying to build more then you can hurt things quickly. HTH. james

 

[gczarny]

Just to answer a few of the questions asked.
1. The waste gate puck is closing all the way into the waste gate hole.
2. The transmission has a 10" 3200 convertor (or looser)
3. The turbo has an aftermarket elbo which is not ported
4. Were not trying to spool in park/neutral
The vehicle was purchased with the motor laying in the trunk. We rebuilt the motor, put it back together, and the motor runs fine and will wind up with no misses or stumbles but the boost never comes in. Could the turbo be the problem? Thanks

are you sure you have restrictor in the "tee" facing right way ?

 

[monkeyy337]

i meant is the wastegate hole ported not the exhaust elbow. and the wastegate puck should be closing on the hole not in the hole if it is going in the hole the you need a bigger diameter puck

Did some more troubleshooting today and found the wastegate puck is not closing squarely on the hole. Guess thats probably the problem.