Boost flutter...revisited
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From: WY
Originally Posted by G1625S
Well, I've always suspected my pump of being a bit of a turd reman....anyway, my pump is pushed toward the head as far as it will go, so one would ASSume there's enough timing to do the job. Just for giggles, I pulled the wire to the KSB (which, on the non-IC version, full KSB advance is given when NO voltage is present) half hoping for good results and half hoping something would fly apart since I haven't started a good carnage thread since I tore up my R&P 
The bottom line is the truck runs great...NO fluttery boost gauge and no overwhelmed wastegate controller. Also, alas, NO smoke once she lights 
Things could be worse, I guess. I'm not sure if my pump was setup for a bulldozer or what, but I'm gonna advance the pump gear a tooth (again; never had it advanced with the new turbo) to make up for whatever is lacking and still have my KSB. So, several pages later, I've at least found a work-around untill I get the gear advanced....and I've also got a tapped banjo to install and yet another pressure gauge to put in the pump top before my Walbro shows up 
Thanks for all the suggestions/comments...I'm sure I'm not out of the woods yet, but maybe we can at least put this one to bed and get some new problems!
Greg
The bottom line is the truck runs great...NO fluttery boost gauge and no overwhelmed wastegate controller. Also, alas, NO smoke once she lights Things could be worse, I guess. I'm not sure if my pump was setup for a bulldozer or what, but I'm gonna advance the pump gear a tooth (again; never had it advanced with the new turbo) to make up for whatever is lacking and still have my KSB. So, several pages later, I've at least found a work-around untill I get the gear advanced....and I've also got a tapped banjo to install and yet another pressure gauge to put in the pump top before my Walbro shows up Thanks for all the suggestions/comments...I'm sure I'm not out of the woods yet, but maybe we can at least put this one to bed and get some new problems!Greg
I"m just curious ...as probly you are, if your paticuler set up just need more timing, or if the pump need to be all the way up cus the gear was off a tooth?
Real glad that you have found the road to the fix!!!!
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From: port crane, NY
I've timed the truck using the plunger-lift method. I could get up to about 1.9mm of lift with the gear in the stock position. I advanced the gear a tooth once upon a time, before the hybrid, but I pulled the pump waaay back to be safe, then started doing more towing and decided to bring it back to stock. There is a set-it-once preload on the spool valve spring that essentially determines the internal pump pressure...and that setting is determined by the pump builder, on a pump stand, I assume. What I'm thinking is that setting may be too loose on my truck (even after fussing with is a bit) and that my internal pump pressure is not high enough even for stock, and so I'm losing out on my dynamic timing, hence tons of smoke and boost. At least all the porting I did on my 12cm housing seems to be working...boost flys to 30psi and stops like it hit a brick wall with my foot to the floor in 4th and by the time I've scanned the gauges, I'm pushing 85mph with temps in the 1100 range
and yes, my truck is indeed a wee tawd, but she's my wee tawd
and yes, my truck is indeed a wee tawd, but she's my wee tawd
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From: WY
just trying to under stand these pumps better, what and were is the spool valve? I printed off the VW, VE pump pic so i'd have pic's to get the visual 
any ways were is this "spool valve spring". Is it in the out lets of the pump to inj lines? The fittings, sticking out the back of the pump?
any ways were is this "spool valve spring". Is it in the out lets of the pump to inj lines? The fittings, sticking out the back of the pump?
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From: port crane, NY
The valve is on the outlet side of the vane pump that supplies pressure to the pump case. It's really only meant to be set once, kind of like a crush washer on a pinion shaft. Basically, pressure reaches a certain point, the spring compresses and fuel is bypassed back to the suction side of the vane pump. More preload on the spring, more internal pump pressure. The good Pastor advised against fussing with this little item, and I tend to agree, as it's really only for the pump builder and people who want to ruin a perfectly good daily driver like me 
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Joined: Mar 2006
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From: WY
Originally Posted by G1625S
The valve is on the outlet side of the vane pump that supplies pressure to the pump case. It's really only meant to be set once, kind of like a crush washer on a pinion shaft. Basically, pressure reaches a certain point, the spring compresses and fuel is bypassed back to the suction side of the vane pump. More preload on the spring, more internal pump pressure. The good Pastor advised against fussing with this little item, and I tend to agree, as it's really only for the pump builder and people who want to ruin a perfectly good daily driver like me
O
ho i see thank 
the crush washer i can relate too! now i can get my pump pic back out and learn!
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