Hi Roger, I installed a Weber DGV, and the fuel pressure is a little over 2.5 lbs.
I ordered the weber after the CD150 went nuts after a rebuild. In retrospect, the rebuild was fine, it was the new fuel pump I installed shoving 5+ psi down it's throat that caused the problems. ----Original Message Follows---- From: Roger Elliott <[EMAIL PROTECTED]> To: Paul Meyer <[EMAIL PROTECTED]>, spitfires@autox.team.net Subject: Re: [Spits] 79 Spitfire with SU carbs Date: Fri, 29 Jun 2007 18:25:34 -0500 I have been chasing similar problems for quite a while. It never occurred to me that the problem could be too high of fuel pressure. What did you need to set the pressure at to make the car run correctly? I stopped at Napa, they had one that could be adjusted 2 - 4 pounds and one that could be adjusted 4-9 pounds. Thanks, Roger Elliott Paul Meyer wrote: >Several years ago I swapped carbs on my '78. >Similar fuel problems resulted, which were eventually identified as being >caused by the new carb requiring less fuel pressure. Idle was ok, but as >soon as I increased rpm or fiddled with the choke, it would roughen or >stall. I too replaced the fuel pump, but that only made things worse. > > >I put in a cheap, in-line fuel pressure regulator, and got some >improvement, but the cheap regulator caused flow problems in high rev >conditions. > >Ultimately, I put in a higher quality fuel pressure regulator, and that >solved it. > > > >Paul F. Meyer > >Home Phone: 781-551-8574 >Cell Phone: 781-801-3170 >e-mail: [EMAIL PROTECTED] > > > > >----Original Message Follows---- >From: David Woerpel <[EMAIL PROTECTED]> >To: spitfires@autox.team.net >Subject: [Spits] 79 Spitfire with SU carbs >Date: Tue, 26 Jun 2007 17:43:27 -0500 > >Hello, > >I am helping a friend with a 1979 Spitfire 1500. He's removed the >Zenith and installed 2 S.U. HS4's. I'm one of the masochistic types >that likes working on SU's and have no problem with the H4's on my MGA >or H1's on the Bugeye Sprite but this problem has us stumped. > >The car has been desmogged, the head lightly shaved (I don't know how >much) and the rest is stock as far as we know. It was running happily >and he decided that he wanted SU's. The carbs are set correctly. We >started with the jet adjusting nut at 12 flats down (yes, they are >centered). The float levels are at 3/16", oil in the dashpot (1/2" >above tube). The car starts and runs on choke and the pistons rise >equally but when the choke is gradually reduced after, 3-5 min., it >starts to stall. Add choke; it runs. Push off the choke and it wants >to die. When we tried hand manipulating the throttle it occasionally >coughs back through the carbs and dies. > >The owner had ordered a new mechanical fuel pump which we installed. It >ran better off choke momentarily but then fuel poured out both float >bowl overflows. I know the mechanical pump isn't putting out too much >pressure so I'm suspecting the float needle and seat. New rubber tipped >ones are on order. The coughing back through the carbs makes me suspect >timing but when it runs it's pretty smooth. Just for kicks, what are >the timing specs for a 79 1500? He has no manual and mine are for my >above cars. > >Any suggestions would be very helpful. Thanks in advance. > >Dave >59 :{) >59 MGA 1500 >05 MCS >Burlington WI >_______________________________________________ >Spitfires mailing list >Spitfires@autox.team.net >http://autox.team.net/mailman/listinfo/spitfires > >_________________________________________________________________ >PC Magazines 2007 editors choice for best Web mailaward-winning Windows >Live Hotmail. >http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_pcmag_0507 >_______________________________________________ >Spitfires mailing list >Spitfires@autox.team.net >http://autox.team.net/mailman/listinfo/spitfires > > _________________________________________________________________ http://liveearth.msn.com _______________________________________________ Spitfires mailing list Spitfires@autox.team.net http://autox.team.net/mailman/listinfo/spitfires