[Syty] Fuel Pump

Thu Apr 20 12:10:06 CDT 2006

THAT lower-mount is precisely where your problems may occur... depending on whether the mount or frame/cradle physically contacts-- either tight or bouncy-- the sheet metal of the inner, baffled gas chamber.  The BIG noise will most likely come from that resonating plate rather than the cradle that the pump sits in (unless it's loose or cracked).  Watch that overstuffed rubber pump-mount doesn't force the filter-sock-collar to jam into... or come within striking distance of that lower baffle plate.  I could see a mini-Big Sid Catlett doing some interesting cymbal solos on that inner structure if you don't watch the mechanical contact points....

Just be glad we don't have those old reciprocating fuel pumpz!  These screw-drives are much quieter... and efficient.

D.O.
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----- Original Message ----- 
From: Jeffrey Smirz 
To: DOlivares 
Sent: Thursday, April 20, 2006 5:37 AM
Subject: Re: [Syty] Fuel Pump

OK, Bosch is OUT.

Racetronix says to leave the factory wiring in place, and they include a rubber pump mount that may help with Ron's noise factor.

Jeff

On Apr 18, 2006, at 8:01 PM, DOlivares wrote:

  OEM IS a Bosch.

  Supposedly, legend has it, the Typhoon and TTA pumps were the best of the breed, but I can tell you from personal experience that my TTA pump was constantly starving out, even from the first day I drove it new in 1989.  All the eventual versions of adjustable-FPR never helped me on the top end. 

  As for the Typhoon stock pump... I haven't driven it enough to give an impression....

  Since you're gonna rewire that harness-- a bit of a romantic exercise in ultimate futility (like cc-ing your heads) unless you're installing a true high-amp pump(s) in a first-gen Grand National, which isn't necessary for street/strip-- you might want to consider the viable alternative of retaining the stock wiring and splicing-in one of those Boost-a-Volt (or whatever they call 'em nowdays) on-demand overdrivers for the FP.  I got one from Kennedy-Bell and it RESURRECTED my stock-schlock Bosch TTA FP.  Too bad I never got to drive it much before I tore the engine down again....
  I'm tempted to install one (basically, a 13-to-18-volt DC-DC Converter which is enabled by a boost-switch) on my 'Clone but with that fat Walbro 255 in there now-- which never chokes or starves-- I'm not sure it will do much good for the cam and injectors I'm currently running.  Your plans might be different.... 

  Think about it,

  D.O.
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  ----- Original Message -----
  From: Jeffrey Smirz
  To: DOlivares
  Sent: Tuesday, April 18, 2006 8:11 AM
  Subject: Re: [Syty] Fuel Pump

  Thanx Dennis.
  I had originally thought the FPR to be the culprit, but confirmed the pump problem using the technique you (and the GM manual) describe.

  You seem to be suggesting that the OEM pump is already a Bosch?  If so, I'll definitely go Walbro, but based on last year's flurry of messages on the subject, I'll likely spring for the extra bucks and wait-time to get Racetronix' plug-n-play harness as well.

  Jeff

  On Apr 18, 2006, at 8:19 AM, DOlivares wrote:

    Thanx for the advance-vote of confidence, Jeff,

    But so far my experience with Walbros versus stock-Bosches strongly favors the FORMER.  And now that I think about it,everystock-Bosch pump I ever owned has been high on longevity but POOR in providing that nice neck-snapping PRESSURE needed for smooth full-throttle response.

    Price-wise, they don't compare well either:  Putting that Walbro 255 in the tank (sans "pulsator") this past Summer only cost me$69 delivered based on a lucky eBay purchase!  That thing will put out over 93psi with my FPR cranked-in all the way-- and before further diaphragm depression from turbo boost!  I'll never go back to Bosch!!  I recommend you don't either.  Be not afraid!  That extra pressure/flow will be there when you most need it... and may well save your pistons during a full-throttle blast in peak-summer weather.  Check out the offerings on eBay under "Syclone Fuel Pump" for the best deals vis-a-vis regular Internet providers of Walbros....

    Although I've yet to publish my unique troubles with my "fancy" FPR-- which went BAD on me at the onset of cold weather here last November-- you might want to VERIFY that it is in fact your FP and not the FPR that is causing your woes.  I was struggling to run with only 11psi when I finally broke down and rigged-up my fuel-pressure hose & remote gauge.  I was heartbroken.  All that grief pulling the tank and the Walbro let me down...?  But, the actual culprit was a collapsed FPR diaphragm.  As soon as I switched-in the old mechanically adjustable FPR I used on my T-Trans Am (never throw away your "obsolete" performance parts!) we were back in business... never a speck of trouble since then!  Check out your start-up/idle pressure (no need to start the engine) by CLAMPING THE FUEL-RETURN LINE with a pair of needle-nosed vise-grips or something equally positive-gripping.  If you still get the same low readings IT IS THE PUMP.  But, if the pressure goes north of 40psi, you've just saved yourself a lot of money and/or acrobatic labor!

    Good luck,

    Dennis O.
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    ----- Original Message -----
    From: Jeffrey Smirz
    To: syty at syty.org
    Sent: Monday, April 17, 2006 8:03 PM
    Subject: [Syty] Fuel Pump

    The Ty's OEM pump is down to about 25 psi.  The poor thing barely runs.  I'm pumping and pulling the tank tomorrow.  There was a lot of talk about Walbros in Feb. '05, but I'm not planning on racing, except the occasional stoplight Grand Prix.  I'm leaning towards a Bosch replacement pump.  Advice is welcome.....particularly if it comes from the one and only serovilo, grtyphoon, bullyhart, merk1993 or any of the other great contributors.

    Jeff
    Syclone #950 (totaled in '99)
    Syclone #1654 (formerly Chris Pearson's)
    Typhoon #1165
    Indy, IN

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