I also posted this on the SSS forums, but I figured the more eyes the better. (this is for a 2003 Silverado SS)

Long story short I'm not showing any boost on my Procharger P-1SC. I bought the truck and the previous owner never actually had boost showing (confirmed this a week after buying it) but he didn't really know how anything worked on the truck (bought it for looks). I replaced the valve and made sure everything was tight. The blower is blowing hard and pushing through lots of air. Previous owner had it sent in and overhauled in October so I know that the blower itself is working. I spent about a week checking lines and such and never found any obvious leaks. I pressurized the hose that goes into my gauge and I can get it to show however many PSI I need it to so I'm sure that the gauge is working. I called procharger and tied the boost gauge line into both places they told me to try, but to no avail.

I finally broke down and took it to a performance shop that installs and works on these all the time. The guy there told me he specialized in GM and has done quite a few SSS's. They diagnosed it as a thoroughly messed up tune and said it would need new injectors if they hadn't been upgraded yet. They told me something to the effect of "the truck is working against itself because the computer is tuned so crazily, and it probably needs injectors if they haven't been swapped yet". They said the blower seemed to be working great and the re-tightened all the connections.

I had gotten a couple lean codes so the injector claim made sense. As you can see from this thread:

http://www.silverado...-injector-swap/

... I was able to complete the swap from the stock injectors to Zippy's suggested Siemens Deka 60lbers. While I was swapping the injectors I addressed the tune issue by sending my PCM to Zippy. I got it back today and was able to try it out for the first time and... still no boost showing . The truck feels peppier than before but I still don't think I'm legitimately getting boost for some reason. Mind you, I've never driven one of these stock so I don't have any reference point, but from what I've seen it should be running quite a bit faster/harder than it is now.

Also, to add a bit more information that could possibly be helpful. I can hear a loud hissing when the engine is idling and the hood is open. It couldve been there the whole time but I just noticed it after putting in the ejectors because I was really looking and listening for things.

Also, the PCV hose that comes off of the top of the engine and connects to the back side of the drivers side manifold came out when I installed the injectors a couple times. I seated it back in, but could I have lost an O-ring or something (if it even has one)?

AND to add another variable... the valve that came in the original kit was one of the cheap aluminum looking ones that they no longer supply with them. I replaced it with a black proflo surge valve about halfway through my diagnostics as I said above. On the off chance that I got a bad valve, could that be the root of all my problems? I hear it blowing off and I also hear the valve rattling when the RPM's drop. I'm running the stock pully so I figured the proflo would be fine.

Any other suggestions, paths to take, or anything at all? I just want this bugger to work!!! I'd like to avoid having to take it in to another shop if possible as I don't think anything major is wrong.

Thanks ahead of time.

 

I am not familiar with zippys tuning ability, but has he been able to straighten out the tune? No CELs? I find the total lack of boost very odd.

 

can you upload a pic of where you have your gauge Plugged into for your boost reading? It just needs to be T'd in with your vaccum line for the blow off valve to the passenger side port on the intake manifold. The only other thing I could think of would be a vaccumm leak, which would be a bigger boost leak. But I think you would have all kinds of codes going on with that.

 

One more thing to check, Make sure crank bolt is tight, you may be spinning the crank pulley on the crank and not making boost. You may have to pin your crank

 

The more I look into it and get suggestions, the more it seems like it might be some sort of vacuum leak. It looks like I'm actually getting like 3-4psi boost at WOT and 6k RPMS. Seems low, so maybe the vac leak has something to do with it?

I sprayed some soapy water on the idling engine and found that this little nipple thing behind the throttle body definitely has a bit of a leak, but I don't think it is the source of the hissing.



The hissing sounds like its coming from the passenger side of the engine as pictured below. (Specifically the part that looks like I sprayed it with soapy water)

 

The part that is bubbling up with soapy water, originally i believe was pcv from your passenger side valve cover. I believe at idle, it would be a vaccum leak, possibly small, but small enough to give you that lean code, because it is air the maf is not reading. If you were NA I would believe you would run leaner from that leak as you upped the rpms. Since you are running the blower, I think the boost is overpowering the vaccum and causing a boost leak right there.

 

Its possible that rubber block off cap is cracked, but hard to see. Pull it off, replace it, and put a small hose clamp on it. I had the vortech blower, similar to the procharger, Mine was capped off there also, mine leaked, and i lost boost at the track, it actually popped off, i had to clamp it on. I also spun the crank bolt out twice and was loosing boost, had to pin that. I would still keep an eye on your crank bolt, its bound to come loose under boost if not pinned.

 

And your boost line is hooked up in the right place, so it should be reading boost fine, unless its something mentioned above.

 

One more thing, On my lq4, my 8psi pulley only made 6psi, and when I added the intercooler it dropped again to 5psi. I had to pulley down to get back up. Even with a small leak fixed, you may not see more than 5-6psi at max shift point on your 6.0 without going smaller on your pulley, or using a overdriven crank pulley.

 

Replaced the cap and took it out for a spin today. Still only getting 4ish psi boost on the gauge. Took the video below. Seems to be working pretty well actually. If it had less gas in the tank, not a large person driving, and no amp/sub she would be going pretty quick!

Supercharged Chevrolet Silverado SS 0-60 - YouTube