Lost boost

[warlord]

Hey fellas , my gn used to push 16-18 psi, now all of a sudden it barley makes 10 psi, i did not make any changes to my car, it just happend all of a sudden, i found a crack on my DS exhaust manifold and just had it removed, welded and put back together with a remflex gasket, i was almost 100% sure that was were my lost boost was going..i checked turbines for any play and oil in my intercooler, all is good, i tried looking for a crack on the pass side manifold, but could not visually see a crack from looking top of motor down , my blm's read 137 then somtimes when i shut it down and restart, my blm will read 128, & somtimes under, car idles fine and runs pretty much decent, except i can notice the slight loss in power at wot....any suggestions
Iac-13
Tps-44
Rpm-650
Bat-13.4



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[warlord]

Im still fighting this problem, once i get to the bottom of this i will post my finds. Some help would be appriciated


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[notacarlo]

Do you have a vac/boost gauge? What does it read at idle for vacuum?

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[warlord]

I have a vac/boost gauge, its a notch above vac


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[Boostian]

Mine did almost the same thing. If it feels almost the same but just the gauge is reading diff check all your hoses and connections that your gauge is tee'd into. Mine were dry rotted. Gauge read wrong, boost was right.


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[85typet]

I thought I was the only one who was having this same exact issue my car builds 10# and even if I unhook the wastegate it wil maybe build 11# I tried replacing the fuel pump and the maf and I don't hear any exhaust leaks

 

[85typet]

And the car has half of the power that it's suppose to have

 

[warlord]

Rgr that. My next move is to check for a clogged cat


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[notacarlo]

Wait... At idle that needle should read 15-18 in/murcury. If it doesn't you got issues.

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[85typet]

b

 

[warlord]

Hey guys.... Good news i found my problem,,,, turns out two of my vac hoses were halfway out, and for some reason the straps i put on them were not tight enough... I think it was due to the size (width)of them, there were about 1/4"wide, so i pushed in both hoses and strapped them with a much smaller tie wrap, it felt much more secure.....BTW the vac hoses that were loose was the one that was coming out of my boost gauge to a tee, and the other was from the very oppisite side (straight) of the tee... Both were almost out from the tee.... I got to say if i didnt double check them id be bald by now . Anyways, i also took car for a test run and she felt like a beast again, wwooooohoooooo!!!!! ...... Thanx guys for chiming in on this problem here.....


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[warlord]

Hi guys just want to reupdate my findings,what i thought that fixed my boost loss wasnt the problem, 2 days later i was back at 9-10 psi,(sry i didnt post it sooner) so i started doing boost leak tests, and found a few more leaks which were vac block gasket, the 2 throttle body shaft seals that are located by tps sensor & throttle cables, bad o- ring on my turbo compressor housing, & egr.......all which i have repaired and still had boost leak, then i just started dabbling with the wastegate arm moving it back & fourth, repeatidly a few times, & viola, boost is back, and been back for over 2weeks, when i 1st figured it out, i was like no way!! Then i parked my car and the next day i drove my car and boost was down to 9-10 psi again, so i rapidly turned my car off opened the hood and started moving the wastegate arm back and forth a few times again, and boost came back, and its been back ever since, now im for sure that it has to be my wastegate puck or the actuator, when i try to move the arm its pretty tight and always feels closed when the car is off, i know if its the wastegate itself i will overboost, but then again like i said the puck doesnt feel like its stuck open....anyways, just wanted to let the community know my findings..... Oh and btw & fyi, all those leaks i found & fixed made my car more awesome....... car idles lovely, and cold starts are amazing, BLM #'s are at a perfect 128 all day..........sweet!!!!!!!!!!!


87 grand national
60 psi mototron injectors
V 5.7 tt chip
Accufab fuel pressure regulator
Walbro 255 fuel pump
Hotwire kit
160 stat.
T04b turbo
K&N cone air filter
Dual radiator fans
Scanmaster