78SportoSC Posted 5September, 2017 Report Share Posted 5September, 2017 Hi all,Long time reader and I finally have a question. We are in the final stages of getting my Dad's 78 SC back on the road (one owner, he purchased it in '77 and drove me home from the hospital in it when I was born!) and the last hurdle is the sporto. Seems like we are not quite getting enough vacuum to throw the clutch. Is anyone here running an electric vacuum pump to power the sportomatic? What were the challenges, how did it turn out, what pump did you use? The focus at the moment is to get the car back on the road, rather than making it super original.Thanks for any help. Link to comment Share on other sites More sharing options...
Russ Posted 5September, 2017 Report Share Posted 5September, 2017 I've looked at doing this with a vacuum pump out of a W124 Mercedes (normally under the back seat) and it was all too hard.Are you sure that the vacuum levels are the problem? have you measured the vacuum the engine is producing?Are you sure it's not the diaphragm not working? or the solenoid not getting 12v to activate the clutch? there's a few other things it could be Link to comment Share on other sites More sharing options...
michel Posted 5September, 2017 Report Share Posted 5September, 2017 @Russ talks with sense Loss of airtightness of motor can effect sporto, though there is a myriad of other components that can impact.good news all can be remedied.Even the previously NLA diaphragm is been remade by a QLD'r I among a few others will be interesting to hear what the issues and remedies are .. sports aren't a dark art despite the many claims. There is also a MLB guy who has occassionslly posted here and extensively on pelican, who did a superlative definitive sporto rebuild thread.. worth digging up as is posts by Grady Clay and a few others PS kudos for you and your dad for keeping the sporto. ??? Link to comment Share on other sites More sharing options...
78SportoSC Posted 5September, 2017 Author Report Share Posted 5September, 2017 Thanks guys, gearbox is currently apart for trouble shooting, worn parts have been replaced all looks ok it seems. The diaphragm is holding vac, the gear lever microswitches have been replaced, just trying to get a step ahead incase this is a road we need to go down, as I mentioned getting her on the road asap is the main focus. Once its back in a good test of the electrics and adjustments looks like the next step.Thanks again, anyone else with advice feel free to chime in. The main symptom is grinding when attempting to go into gear. Link to comment Share on other sites More sharing options...
911_sporto Posted 8September, 2017 Report Share Posted 8September, 2017 Hi 78SportoSC, Bremith on typ901 fitted one to his 3.0L. Even with a new diaphragm, his rebuilt servo would not work effectively. You need around -15 psi to pull in the clutch. Cost him about $150 and it also needed an extra switch. This type of gauge can be adapted to check your vacuum-http://www.ebay.com.au/itm/Blue-Air-Conditioner-R404-R134A-R22-Refrigerant-Low-Pressure-Gauge-PSI-KPA-New-/142079642014?epid=2114662422&hash=item21149b499e:g:ioMAAOSwy5BZpQvI Link to comment Share on other sites More sharing options...
Zelrik911 Posted 13September, 2017 Report Share Posted 13September, 2017 @Russ talks with sense Loss of airtightness of motor can effect sporto, though there is a myriad of other components that can impact.good news all can be remedied.Even the previously NLA diaphragm is been remade by a QLD'r I among a few others will be interesting to hear what the issues and remedies are .. sports aren't a dark art despite the many claims. There is also a MLB guy who has occassionslly posted here and extensively on pelican, who did a superlative definitive sporto rebuild thread.. worth digging up as is posts by Grady Clay and a few others PS kudos for you and your dad for keeping the sporto. ??? The sporto guy in Melb uses the name ' rodoredas ' on PParts & is still a bit active. (His special interests are 911 Sportos & Zenith carbs, both are known cures for happiness.)His real name is Shane - I met him a few years ago and he is a hell of a nice guy.http://forums.pelicanparts.com/new-zealand-australia/507877-sportomatic-gearbox-rebuild.html Link to comment Share on other sites More sharing options...
Flatout Posted 20September, 2017 Report Share Posted 20September, 2017 Could you run a vacuum tank? Would that give enough vac, would at least stabilise it. I ran one in an old rotary as the large ports and intake meant little to no vac, that helped a lot. Just to clarify I know nothing about sporto's though. Just a different option to consider. Link to comment Share on other sites More sharing options...
911_sporto Posted 20September, 2017 Report Share Posted 20September, 2017 Could you run a vacuum tank? Would that give enough vac, would at least stabilise it. I ran one in an old rotary as the large ports and intake meant little to no vac, that helped a lot. Just to clarify I know nothing about sporto's though. Just a different option to consider.Hi Flatout, They already have a tank. I think that the problem with some of the newer motors is similar to your old rotary.... Link to comment Share on other sites More sharing options...
Zelrik911 Posted 20September, 2017 Report Share Posted 20September, 2017 I know zilch about sportos as well. But I do know about TR6 Fuel Injection which uses vacuum to control the injector pump.Because of the issues outlined, some TR6 guys use diesel alternators which have a vacuum bump built into the end as diesels have no natural vacuum (not directly suitable for 911 though).I will ask around, but with the popularity of diesel cars - there must be a modern compact vacuum pump somewhere that could be adapted.Here is a US muscle car one for $US600. Its nice however you should find one for a fraction of that price.https://www.mpbrakes.com/accessories/silent-drive-vacuum-pump-ac9001k.asp Link to comment Share on other sites More sharing options...
78SportoSC Posted 27September, 2017 Author Report Share Posted 27September, 2017 Hey Guys a little update. After adjustments we can get D and D3 R and P but L remains a problem. Gearbox pulled and opened again to look for any obvious problems but none evident all worn items were replaced the first time around. Since we can select most of the gears I guess we can knock vacuum off the list of problems. We are just going to enjoy her for a while in D! Has anyone else been down this road? Link to comment Share on other sites More sharing options...
911_sporto Posted 28September, 2017 Report Share Posted 28September, 2017 Is it a 3 or 4 speed box? 1st can be very hard to engage if the splines on the shift coupler are not properly aligned on the 4 speeds. Even with 2nd, 3rd and 4th working nicely.I still highly recommend actually measuring the vacuum....just to be sure you're not prematurely wearing out your synchros. Link to comment Share on other sites More sharing options...
78SportoSC Posted 28September, 2017 Author Report Share Posted 28September, 2017 Its the 3 speed. Good idea, The Syncro on 3rd was worn and replaced other two looked ok. There hasn't been a whole lot of gear changing going on just crusing in D, its such a tease. Good to have her back though. Link to comment Share on other sites More sharing options...
78SportoSC Posted 1February, 2018 Author Report Share Posted 1February, 2018 It was chased down to multiple bad grounds as the wiring has been tampered with over the years. No pump required. Great news, thanks for your help everyone. Link to comment Share on other sites More sharing options...
ELSPORTO Posted 5February, 2018 Report Share Posted 5February, 2018 Great story, great ending. Go the sportos! Link to comment Share on other sites More sharing options...
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