Can't boost over 10#

[NY_GN]

Started with bad MAF, then coil pack went out.

Put in New Maf, cleared code. Then put in New coil pack and module. Did compression test; good, no vac leaks and no cracked headers.

It's firing right, but won't boost over 10#.
Could I have an issue with spring in my external waste gate?

 

[TurboBuRick]

Remove the gate and inspect. It may be stuck open.

 

[NY_GN]

Remove the gate and inspect. It may be stuck open.

Ok, I'll try that. Thanks.

 

[NY_GN]

Ok, I'll try that. Thanks.

Checked the gate, not stuck.

 

[bison]

Exhaust restriction or inlet restriction or damaged blades on the turbo or wastegate not setup for proper range. Post pics of the setup and what wastegate


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[earlbrown]

When you say ''new MAF' do you mean a replacement unit from a parts store?


Also, have you welded up the crack in the drivers side header yet?

 

[NY_GN]

When you say ''new MAF' do you mean a replacement unit from a parts store?


Also, have you welded up the crack in the drivers side header yet?

I have a new maf on order, a granitelli MAF from my camaro is in it right now. It's flowing fine and hooked up to my maf translator.

Welded gusset on header 2 years ago, no leaks.

We'll see when the new maf gets here.

 

[djj624]

I had the same problem with not being able to go past 10lbs. It turned out to be s bad external wastegate. I had an old atr unit that came with the car and I thought the insides were probably toast (diaphragm torn ,stuck rod, bad spring) turns out the rod moved very freely the diaphragm was like new, and different springs did nothing. I don't know why it wouldn't work but I replaced it and boom instantly went past ten and works like it should.

Galaxy S7 Edge

 

[djj624]

I had the same problem with not being able to go past 10lbs. It turned out to be a bad external wastegate. I had an old atr unit that came with the car and I thought the insides were probably toast (diaphragm torn ,stuck rod, bad spring) turns out the rod moved very freely the diaphragm was like new, and different springs did nothing. I don't know why it wouldn't work but I replaced it and boom instantly went past ten and works like it should.

Galaxy S7 Edge

Galaxy S7 Edge

 

[NY_GN]

I did a few WOT blasts and it seems the MAF isn't flowing consistent and won't reach 255. So, I've got 3 bad MAFS on hand, still waiting on new one in the mail. The car pulls hard, just tops out at 10#. we'll see what happens.

 

[Rafs-T-Type]

You aren't reading the boost off the stock dashboard are you?

 

[NY_GN]

You aren't reading the boost off the stock dashboard are you?

Hell no, I have a mechanical autometer gauge on my pillar. It reads fine, plus you feel the difference between 10 & 25#.

 

[John Larkin]

I had a loose intercooler hose once that leaked boost. Check those clamps.

 

[NY_GN]

I had a loose intercooler hose once that leaked boost. Check those clamps.

That happened to me before too, I wouldn't pop all the way off just loosen up under boost. When it first happened, I reclamped all couplers.

 

[NY_GN]

Got it fixed, but holy shit was it a pita.

-New MAF, Same problem
-New coil pack, Same problem
-checked all couplers, Same problem

Ended up being exhaust leak, pass side, header to the crossover. Pulled the header, that gasket was leaking too. All the numbers on my scanmaster were good, but that leak was as clear as day.

Fixed all that, then started backfiring thru the air filter, but I could finally get up to 20# and quickly.

Changed coil pack module and then blew the coupler off my pipe from turbo to ic. Fixed that on the side of the road.

Everything is good to go. Wow I missed that loud spool and instant pull and even that horse sneeze.

 

[1986 Buick GX1]

I'm glad you found the problem. And thank you for posting the results.

 

[NY_GN]

I'm glad you found the problem. And thank you for posting the results.

Thanks, and I hate when I read old threads without results. Maybe this helps someone out.

 

[GNRick]

Did you replace the header gasket? Mine is leaking on the DS. Thinking of using copper RTV this time.

 

[NY_GN]

Did you replace the header gasket? Mine is leaking on the DS. Thinking of using copper RTV this time.

luckily I had a set gaskets laying around. The spool is instant, glad I found that leak.

 

[bison]

Those gaskets won't last long unless the header flanges are flat and thick and the bolts are cranked down really good.


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