Need help can't get any boost

[slow305]

Wow, I have this exact same problem. When I bough the car it was boosting fine. I bought an RJC boost contoller and Autometer boost gauge and was speeding around at about 12-14 pounds with just an adjustable fuel pressure regulator. It then just started to loose boost over time (over the course of about 2-3 months last summer), and now, I can't get it over 5. The first thing I did was pull off the cat to see if it was plugged up. There was some loose debris in it, so I dumped it out, but when I drove it around without it on at all (open downpipe), it still wouldn't boost over 5.

I then thought it was vacuum lines, nope. Replaced the wastegate and all intercooler hoses and filled the intercooler with water and cleaned it out, still didn't solve the problem. I even pulled the hose off the wastegate and plugged it up so the car would boost until it exploded, but nothing. I then thought that it might be the stock headers leaking, preventing the boost from climbing, so I bought a set of Poston headers and crossover and stuck them on last week. Still nothing. I'm about to resort to pulling the inake manifold off and replacing all the gaskets to see if that fixes it.

Anything you can find that would prevent me from doing this, please let me know. Otherwise, this is what I would suggest doing before throwing parts at it trying to fix the problem like I did. On the other hand, the car probably need some of these things anyway. :wink:

 

[Dabigguy]

It doesn't make sense. Sounds like it is making boost, but it isn't making it to the intake. Where is it going to? Sounds like the puck isn't sealing for some reason. Maybe something is stopping it from closing all the way. Has anyone looked at the puck's imprint that is left on the turbo?

 

[ricky87gn]

Ok so this morning went and dropped the cat it was clean hollowed it out anyways. Pulled the exaust elbow off checked it out and it looked like it was seating there just fine. This is really starting to get to me and making me a bit angry. Damn this car but I love it when it runs correct. Any other ideas guys. I'm giving them all a shot and see what happens

 

[ricky87gn]

Wow, I have this exact same problem. When I bough the car it was boosting fine. I bought an RJC boost contoller and Autometer boost gauge and was speeding around at about 12-14 pounds with just an adjustable fuel pressure regulator. It then just started to loose boost over time (over the course of about 2-3 months last summer), and now, I can't get it over 5. The first thing I did was pull off the cat to see if it was plugged up. There was some loose debris in it, so I dumped it out, but when I drove it around without it on at all (open downpipe), it still wouldn't boost over 5.

I then thought it was vacuum lines, nope. Replaced the wastegate and all intercooler hoses and filled the intercooler with water and cleaned it out, still didn't solve the problem. I even pulled the hose off the wastegate and plugged it up so the car would boost until it exploded, but nothing. I then thought that it might be the stock headers leaking, preventing the boost from climbing, so I bought a set of Poston headers and crossover and stuck them on last week. Still nothing. I'm about to resort to pulling the inake manifold off and replacing all the gaskets to see if that fixes it.

Anything you can find that would prevent me from doing this, please let me know. Otherwise, this is what I would suggest doing before throwing parts at it trying to fix the problem like I did. On the other hand, the car probably need some of these things anyway. :wink:

Wow now I don't feel so bad knowing some one else is having the same problem. If you happen to figure it out before I do please tell and I will do the same for you also. Thanks

 

[stugots]

Check the puck, i had the same problem and turned out to be the puck stuck.

 

[ricky87gn]

Check the puck, i had the same problem and turned out to be the puck stuck.

Ok so went out to the ol car and took the elbow of the puck looked good like it was sealing just fine and moved freely. Starting to get very mad at this car and thinking about spending the money and just buying a whole new turbo

 

[BlackBandit]

Does the turbo spin freely? Or does it drag?

 

[ricky87gn]

Does the turbo spin freely? Or does it drag?

Hi turbo spins nice and free no marks on the housing. Got the turbo from "86 tr" he is a member on this board. And pulled it off his car and told me that there were no problems with the turbo. My old turbo did this exact same thing that's why I got a replacement turbo but that did not fix it so now I'm just dumb founded.

 

[BlackBandit]

Okay, I know the puck thing has been discussed but I'm starting fresh. So, are you sure the puck is large enough to cover the wastegate hole? Allot of guys have ported out the holes on their turbos to stop boost creep and I know you bought this turbo from someone else.

Second, you could eliminate the intercooler as the problem by running some hose from the turbo to the throttlebody.

Do you have any big exhaust leaks?

There really is only a few things it could be. Something is blocking the air flow to the engine (intercooler), The exhaust system isn't flowing through the turbo or at all (plugged exhaust, leaking headers, wastegate puck not sealing, bad wastegate), or it could be the turbo. It doesn't sound like it's the turbo though. (it spins freely, no marks, ect)

You could verify the turbo is getting oil by unhooking the oil feed line and cranking (not starting) the engine. Also you should check to see that the drain isn't restricted.

One other thing you could do is wire the wastegate puck closed. This would do the same thing unhooking the wastegate vacuum line should do but eliminates the wastegate as a cause.

Let me know if you need any clarification. HTH james

 

[ricky87gn]

Okay, I know the puck thing has been discussed but I'm starting fresh. So, are you sure the puck is large enough to cover the wastegate hole? Allot of guys have ported out the holes on their turbos to stop boost creep and I know you bought this turbo from someone else.

Second, you could eliminate the intercooler as the problem by running some hose from the turbo to the throttlebody.

Do you have any big exhaust leaks?

There really is only a few things it could be. Something is blocking the air flow to the engine (intercooler), The exhaust system isn't flowing through the turbo or at all (plugged exhaust, leaking headers, wastegate puck not sealing, bad wastegate), or it could be the turbo. It doesn't sound like it's the turbo though. (it spins freely, no marks, ect)

You could verify the turbo is getting oil by unhooking the oil feed line and cranking (not starting) the engine. Also you should check to see that the drain isn't restricted.

One other thing you could do is wire the wastegate puck closed. This would do the same thing unhooking the wastegate vacuum line should do but eliminates the wastegate as a cause.

Let me know if you need any clarification. HTH james

I will give it all another shot in the morning I got the intercooler off the car cleaned it all out nothing in it just a little dirt and grime also no holes any where in it.

 

[BlackBandit]

Another thing to check is the intercooler hoses. They can split so they don't look broken but the crack opens up when pressure tries to build.

Can you hear the turbo spool?

 

[ricky87gn]

Another thing to check is the intercooler hoses. They can split so they don't look broken but the crack opens up when pressure tries to build.

Can you hear the turbo spool?

Hi I thought that might have been the problem before so I replaced all the hoses with new ones but I will check them again.

 

[SouthernCal GN]

Hi, Ricky,

Have an idea- tomorrow, wire the wastegate shut, and take a light run up your street- watch the boost gauge to see if it builds beyond 5 psi...

 

[ricky87gn]

Hi, Ricky,

Have an idea- tomorrow, wire the wastegate shut, and take a light run up your street- watch the boost gauge to see if it builds beyond 5 psi...

Hi I will give that a shot in the morning letting the innercooler dry out for the night before I put it back in. Wow the motor looks good when its clean LOL.

 

[TURBOPOWERED68]

subscribing.

 

[SouthernCal GN]

Hi I will give that a shot in the morning letting the innercooler dry out for the night before I put it back in. Wow the motor looks good when its clean LOL.

The object is to determine whether the actuator is the problem- with the wastegate wired shut, there's potential for you to do damage if the car overboosts, so take it easy!

 

[BlackBandit]

Hi, Ricky,

Have an idea- tomorrow, wire the wastegate shut, and take a light run up your street- watch the boost gauge to see if it builds beyond 5 psi...

I agree, this is an excellent idea. Pure genious!!!:biggrin:

 

[87we410877]

I agree, this is an excellent idea. Pure genious!!!:biggrin:

Either your waste gate is bad (stuck open ), or your intercooler has a huge hole in it. I have a stock waste gate if you want it. Let me know.

Like others have said, do you hear the turbo spool? If not, its deffinately the waste gate.

 

[Jerryl]

Ok, here is a dumb question :

Where is the boost gauge hooked up and are you sure the line to the gage is ok?
IOW, Does it truly feel like 5 psi?

 

[BlackBandit]

Like maybe the line to the boost gauge is cracked or if he's still using the factory set up the map could be bad.