The Triumph Dolomite Club - Discussion Forum

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PostPosted:Fri Mar 19, 2021 9:26 pm 
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TDC Shropshire Area Organiser

Joined:Sun Aug 21, 2011 4:12 pm
Posts:6086
Location:Highley, Shropshire
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So I have given up trying to fit the mechanical pump. I have bit the bullet and bought a Huco pump, it's low pressure so doesn't by all accounts require a pressure regulator, but on receiving the pump today it says it is recommended that a emergency cut off switch be incorporated in the electric system. For people that don't know it's a switch that in case of a accident the fuel is cut off automatically.
Sounds like a reason to fit one so ordered one from Ebay but it takes three weeks to arrive.
I don't plan on having a accident imminently.
The only other thing I think I need is a filter but does it go on before the pump?
Alan
Most cars have a filter built into the tank pickup to catch the worst of any crap before it gets to the pump. Dolomites are not blessed with one of these, so best to fit a line filter between the tank and the pump.

I use fuel shutoff inertial switches on my high pressure EFi powered cars, it's a sensible precaution in that case, where you have 40+ psi running through the lines. Not really so needful on a carburettored car with only 3 or 4 psi on tap. Switching off the ignition will stop it in any case. So the only time you might NEED an inertial switch is when the car is upside down and you are unconscious. In those circs, you are already in big trouble! Though I was always a fan of the concealed manual switch in the powerline to the pump. It makes a good thiefproofing device! On my GT6 MkII convertible, I used the redundant HRW switch (clearly labeled as HRW) to power the pump, hiding in plain sight on the dash!

By an odd coincidence, the white Sprint shuddered to a stop on me today! I took it for a little run to blow out the cobwebs after first warming it on the drive. After about 15 mins running and 5 miles driving it started running rough, refusing to rev above 2000rpm and spluttering, I coaxed it another mile or so before I found a spot to turn round then started back, doing another 2 miles at slowly decreasing speed till it cut out on a slight uphill bit and refused to restart.

Lucky me, i'd just rolled it back onto the verge when a neighbour passed by and stopped to see if I needed help, so I blagged a lift home, got some tools and another car and went back to see what the problem was.

Because the rev counter had been steady throughout the rough running, I tentatively eliminated points, condenser and coil from my enquiries and went first to the boot where I physically checked the presence of fuel in the tank by removing the sender unit, half a tank at least there so next to the carbs, I removed the pipe from the front carb and switched the ignition on and, though the pump was clattering furiously, no fuel emerged. Ignition off again and the float bowl lid removed to show, as expected, a dry float chamber. I obviously had a line blockage and my thoughts turned to the fuel hoses under the car, they were all fairly new when I got it, but were they REAL R9?

Back to the boot and pulling the pipe off the pump allowed fuel from the tank to flow freely from gravity, no problem in the tank then! Pipe returned to filter and pump, I tried the other side of the pump, less flow but still enough, I replaced that pipe too and moved to the PRV, access was a bit poor but I managed to get the pipe off the engine side of the PRV without too much cussing. At this point, there was no flow from gravity (not that I expected any, at that point I was higher than the top of the tank) switching the ignition on got me no more than a feeble trickle despite the pump racketing away. So I turned the PRV up from it's default 1.5psi setting to 4 psi, that increased pressure to what I considered might be workable. I reconnected the pipe and a swift recheck of the float chambers showed them full now.

However, the car STILL refused to even try to start, not so much as a cough and the battery was going flat. I checked the points gap and opened it slightly, carefully inspected dizzy cap and rotor and checked the plugs, all OK but still no start, even with my (Ex Jeep Cherokee Chief) huge slave battery connected via jump leads. Until suddenly, just as I was about to give up and get the car recovered (no easy feat as mine is auto too) it burst into life, strong and sure on all 4 pots, WEIRD! I drove it the last 3 miles home and it was like nothing had happened, pulled strongly and idled fine. I switched off at home and it restarted immediately.

Now it's glaringly obvious that I have a problem in the fuel lines, it shouldn't need 4 psi to open the needle valves (there was no flooding at this pressure setting which I half expected) SOMETHING is slowing the fuel down, so I will replace all the soft lines with known real R9 and blow out or replace the hard lines as needed. I also need to check the other side of the PRV to see what sort of pressure is there, it may be that the PRV is malfunctioning (my fault for praising it in a post further up this page!) Why once it HAD fuel, it wouldn't start, until suddenly it did, I will postpone until a) I've fixed the lines and b) it does it again and I can check other things! But if the PRV IS duff, i'm definitely going for one of those recon SU pumps which, by rights, shouldn't need a PRV!

Steve

_________________
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.


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PostPosted:Fri Mar 19, 2021 11:31 pm 
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Future Club member hopefully!
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Joined:Mon Jun 03, 2013 4:48 pm
Posts:1505
you can fit a bump cut off as fitted to cars like Fords or Landrovers, the earlier type two wire ones are easy to fit but as the dolomite suspension may be slighty harder than a modern car there is a risk that even a small speed bump or pothole can trigger it, the upside is that if you fit it in the cabin area it can act as a immobliser as you can activate the cut off by hitting it and to reset its a simple case of pressing the button on top.
I've fitted a morris Minor electric fuel pump on the drivers side turret on the 1850 but no cut off switch

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PostPosted:Wed Mar 24, 2021 7:17 pm 
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TDC Shropshire Area Organiser

Joined:Sun Aug 21, 2011 4:12 pm
Posts:6086
Location:Highley, Shropshire
Just a quick postscript to my own problem, it turns out the pump has a built in metal filter on the tank side and this was blocked solid with crap and rust from the tank, you can just see it in front of the pump in this picture.


Image

I removed it and tapped it on a hard surface and dislodged a lot of loose rust and sediment and then washed and backflushed it with brake cleaner, but I could still barely blow through it and the fuel pressure at the carbs was STILL pitiful. This filter is part of the pump, probably only sold with it, so the pump will have to go, it looks like one of the £15 chinese ebay sort, so no great loss anyway and I've ordered a new Osias type pump (which needs no PRV and should be quieter) for underbonnet mounting and I'll put a disposable type line filter in the boot where the pump was and keep an eye on it. At a couple of quid a pop I can afford to keep a couple in the glove box and swap them out if they get too choked up.

Interestingly the tank was supposed to have been cleaned and tested before I got the car, when I first got it running and for a year or more after, I ran it on a can in the boot to preserve the tank's allegedly pristine status, only connecting and filling it when it was MOT time (when I found out the tank sender was duff) I'm beginning to think everything the PO did is suspect at the very least.

It's back running again, but now has an annoying hesitation when blipping the throttle sharply that it never had before. Probably from me messing about with the points at the side of the road when I didn't need to! I'll get to that when I 've changed the pump etc and know it's NOT fuel related.

Steve

_________________
'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.


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PostPosted:Wed Mar 24, 2021 8:55 pm 
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Joined:Mon Dec 12, 2016 9:53 pm
Posts:1171
Location:Harrow Middlesex
Ive fitted a fuel cut off switch from Rover 45 to mine, and have recently cut a hole in my tank, to fit a in tank fuel pump,when looking in side my tank it looked to be in good condition and lucky no patches have been welded to it

Dave


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