Still no boost

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May 24, 2010 | 07:58 AM

wmiller

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From: North East, MD

Still no boost

Still can't find my boost leak. Truck will only make 22-25lb boost on hard accell and is egts seem lot higher than they should be. When I get on a little running down the road the turbo doesn't want to light. Feels like I have too big a turbo but with 2s should have more than plenty of fuel to spool it. Checked up pipes and exhaust manifolds for exhaust side leak and can't find any signs. Put my old y pips back on to by pass the intercooler and no luck. My driver side intake manifold has a small crack in the nipple but don't really see how it could leak past the clamp. I'm planning on pulling both intake manifolds and checking to see if maybe leaking around the head. The only other thing I could possibly think of is something with the turbo but it has less than 7k miles on it.

May 24, 2010 | 10:04 PM

cowmilker08

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Joined: Oct 2008

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From: Avilla, IN

Have you tried a boost leak detector?
Does the smoke clear up ever?
Faulty gauge or leaks in the fittings leading up to gauge?
Bad sensors could cause low boost also.

May 25, 2010 | 10:56 AM

glasseater

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From: hillsborough nj

there's a spot on the intake manifold where the boost line goes into... that boost line tells the computer how much boost its making and what it needs to do... if that little fitting is broken or if the hose is loose the computer won't fuel past a certain point... on an untuned truck it'll make 0 boost and can't get out of its own way
check for that line/fitting

May 25, 2010 | 09:16 PM

oldbird1965

Fleet Owner

Joined: Aug 2004

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From: AZ

x2 on what Phil said. The boost leak detector found 4 leaks for me! Good ol soapy water!

May 28, 2010 | 10:19 PM

wmiller

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From: North East, MD

Update: Still no luck. Put a new MAP sensor in it no change. Tried a different computer that was known to be good...again no luck. Ran it down the road with scanner and couldn't find anything out of the ordinary in live stream data.

Truck is obviously getting plenty of fuel ( sky high egts and LOTS of smoke). I'm kinda leaning towards bad turbo

. I have the EBPV gutted and solenoid removed and plugged. Any reason that having that big cylinder empty would be causing turbo to starve? The harness that controlls it is unplugged because if left hooked up when the computer calls to cycle the butterfly valve it will dump lots of oil into that cylinder and starve the turbo.

May 28, 2010 | 11:33 PM

1997F-350

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From: SHELTON, WA

Quote:

Originally Posted by wmiller

no i had mine unplugged and it ran fine. whats the condition of your exhaust housing/ex turbine? fins effed up from high egts? i'd imagine you still have the 1.15 (IIRC) stocker with 2's yeah?

May 30, 2010 | 09:43 PM

wmiller

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From: North East, MD

Good news I may have found the problem. Went to pressure test the motor and couldn't get to hold any pressure. After some inspection one of the bolts was missing form the passenger side intake manifold.

After diging in the valley I found the bolt that who ever put my motor together obviously dropped aqnd forgot about. EGT are more controlable, turbo spools better and can hit about 30 now. Gonna pull the manifold and re silicone and see what happens.