CharlesElliott Posted January 24, 2008 Share Posted January 24, 2008 I recently bought a Spa oil pressure sender, and it seemed to make sense to make use of the 'dual gauge' option and have a fuel pressure gauge too. 😬 Now I'm thinking about fitting it. The car is a standard K-series with the plastic fuel rail - it's a race car and whilst we are allowed to fit additional instruments, I cannot just ditch the standard high pressure hose that takes the fuel from the chassis outlet pipe to the fuel rail. My first thought was to buy a T-piece with a tapping for the sender. Think Auto do one of these (M14 x 1.5 Male to Female) but it doesn't seal on the flared pipe . Has anyone found a suitable T-piece, or how else have people fitted fuel pressure gauges when they have the plastic fuel rail? Charles --- My SuperGraduates 2006 diary My SuperGraduates 2005 diary, My Caterham Academy 2004 build and race diary Link to comment Share on other sites More sharing options...
Peter T Posted January 24, 2008 Share Posted January 24, 2008 Does the rail have a pressure take off point? Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 24, 2008 Author Share Posted January 24, 2008 No Link to comment Share on other sites More sharing options...
Peter T Posted January 24, 2008 Share Posted January 24, 2008 You could change the pipe that runs from the pump to the filter and incorporate a take of from there. No scrap that idea as it would only give you pump pressure before the pressure regulator. ☹️ Edited by - Peter T on 24 Jan 2008 17:31:50 Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 24, 2008 Author Share Posted January 24, 2008 The only regulator (I think!) is at the output end of the fuel rail, so (roughly) anwhere on the line between filter and rail should be OK. Having looked into it a bit more, something like this seems the normal way of doing it. However, this would really mean cutting the chassis to fuel rail pipe, which I'd rather not do. Link to comment Share on other sites More sharing options...
Peter T Posted January 24, 2008 Share Posted January 24, 2008 Is the pipe M14x1.5 female? I might have something that will fit. Link to comment Share on other sites More sharing options...
Peter T Posted January 24, 2008 Share Posted January 24, 2008 Can the adapter be unscrewed from the plastic fuel rail or is it part of it? Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 24, 2008 Author Share Posted January 24, 2008 Thanks Peter. At the chassis end, it is M14 x 1.5mm male, over a flared copper pipe. The high pressure hose is obviously M14 x 1.5mm at the chassis end and a custom fitting at the fuel rail end. It can be unscrewed (from the rail) but I think it's a Rover only fitting. Apparently it's a Saginaw type fitting (see here) and scroll down a bit, hence why there are slightly special sealing requirements and why the T piece I got from Think doesn't work.... Charles --- My SuperGraduates 2006 diary My SuperGraduates 2005 diary, My Caterham Academy 2004 build and race diary Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 25, 2008 Author Share Posted January 25, 2008 Anyone fitted one? Charles --- My SuperGraduates 2006 diary My SuperGraduates 2005 diary, My Caterham Academy 2004 build and race diary Link to comment Share on other sites More sharing options...
strij Posted January 25, 2008 Share Posted January 25, 2008 I had the same problem after buying an ex race R400 engine with a stack fuel pressure sender badly fitted, I eventually made an inline adaptor to go into the connection between the metal fuel line and the rubber pipe to the fuel rail. I considered making an adaptor to go between the rubber pipe and the fuel rail but the stack sender is a heavy lump and I did not want it mounted on the end of a plastic rail and subject to engine vibration. When I got the engine, someone had drilled and tapped the back of the fitting on the end of the rubber pipe that mates with the rail and fitted the sender, on inspection I found that the sender only needed 3/4 of a turn before it fell out leaving a hole pointing at the driver side bulkhead, highly dangerous. When I get somewhere to host pics of adaptor I will. Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted January 25, 2008 Share Posted January 25, 2008 I changed my pressure regulator for one with an extra outlet and put the sender into thhis Just visible at the top of this picture here Edited by - Alex Wong on 25 Jan 2008 12:59:19 Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 25, 2008 Author Share Posted January 25, 2008 Thanks strij and Alex. If I'm going to do it, putting an inline adaptor into the chassis to rail hose seems the best option - shame there isn't a T piece that will fit onto the M14 as it comes off the chassis (at least not one that will seal with the type of fitting). Alex - would be a good option but I have to keep the standard FPR. Charles --- My SuperGraduates 2006 diary My SuperGraduates 2005 diary, My Caterham Academy 2004 build and race diary Link to comment Share on other sites More sharing options...
Kevsta Posted January 25, 2008 Share Posted January 25, 2008 Excuse my ignorance, but what advantage is it to know the fuel pressure? Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted January 25, 2008 Share Posted January 25, 2008 I diagnosed a failing fuel pump with mine, and also a wiring problem to the fuel pump. Both times I had a misfire. If you've ever had a misfire that you've struggled to find the cause for, you'd feel that it was a good idea. Link to comment Share on other sites More sharing options...
Kevsta Posted January 25, 2008 Share Posted January 25, 2008 Fair comment, but the hassle it seems to be causing (can see the hassle it could save though) plus added weight for a race car seem to outweigh (excuse the punn) the effort. Have struggled to find a similar problem before (turned out to be lamda) so can see advantage. Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 27, 2008 Author Share Posted January 27, 2008 It has little value (unless the pump is failing). But it's there to be measured 😬 To be slightly serious, it could also show a fuel starvation, particularly round left handers towards the end of a race. Weight isn't an issue, I have to use lead to bring the car up to the minimum weight anway. Charles --- My SuperGraduates 2006 diary My SuperGraduates 2005 diary, My Caterham Academy 2004 build and race diary Link to comment Share on other sites More sharing options...
philwaters Posted January 27, 2008 Share Posted January 27, 2008 Is the sender safe to use with fuel? Might be worth checking with Spa as i might have seals in it that won't like the petrol. Just a thought.... Good idea though as I had an adjustable regulator that was loosing pressure when it got hot. I couldn't work out why my car was rich to start when starting off and then gradually getting lean by the end of a 1/2 hr blat.... certainly would have helped. Phil Waters Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 30, 2008 Author Share Posted January 30, 2008 It is the sender supplied by Spa with the fuel pressure gauge so I hope so! Charles --- My SuperGraduates 2006 diary My SuperGraduates 2005 diary, My Caterham Academy 2004 build and race diary Link to comment Share on other sites More sharing options...
Grubbster Posted January 30, 2008 Share Posted January 30, 2008 Charles am I being too simple? Can't you just cut the rubber fuel hose that goes to the fuel rail and put a T piece in the line? Your rubber hose is probably long over due for replacement anyway so may as well replace it (just cut the crimps off the ends and attach the end fittings to new hose with jubilee clips (a fiver from halfords). It's only taken four and a half years - I have started my website at last! Early days yet . . . Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 30, 2008 Author Share Posted January 30, 2008 Steve - the hose has already been replaced 😬. Unfortunately I couldn't really just replace the hose and jubilee clip it because that would have been an unauthorised modification . I can T piece it but that still feels a bit on the unauthorised side.... Charles --- My SuperGraduates 2006 diary My SuperGraduates 2005 diary, My Caterham Academy 2004 build and race diary Link to comment Share on other sites More sharing options...
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