The Triumph Dolomite Club - Discussion Forum

Sorry JPB, have to disagree, look at Peugeots, French admittedly, but the inertia switch is in the engine bay

So long as it is solidly mounted to the shell, at the correct attitude, it will work.

Get one from an old Jaguar XJS. The designed locating point is on the footwell side wall, goes nicely on the inner wing, just use a little bracket to get it vertical.

When i have broken down and found no fuel in the bowls, i have tried opening the cap and then trying for several minutes more, with little luck.

Im really at a loss. i use my car everyday to get to work and back so i need to fix this problem once and for all.... i just can't find it lol. also got its MOT due 20th this month and at the moment it won't even make it to the test center . can i drill a 2.5mm hole in the fuel cap or something? (on the underside so water doesnt get in)... im out of ideas

Triumph1300 wrote:....look at Peugeots.....

Aw, do I have to?
There are two students' Peugeots in the practical bays at the moment - doubly annoying as I want to get the Dolly in there for a service - one is a 104zs which has a camshaft-driven, mechanical pump, the other a 106 whose inertia cutout is under the driver's seat as it is on the equivalent Citroen, I'd be interested to know which models have the cutout under the bonnet, just so I know where to apply the hammer/BFM when we get one in which has refused to start in "mysterious" circumstances.

Dolly Unlimited wrote:When i have broken down and found no fuel in the bowls, i have tried opening the cap and then trying for several minutes more, with little luck.

Im really at a loss. i use my car everyday to get to work and back so i need to fix this problem once and for all.... i just can't find it lol. also got its MOT due 20th this month and at the moment it won't even make it to the test center . can i drill a 2.5mm hole in the fuel cap or something? (on the underside so water doesnt get in)... im out of ideas

As has been suggested by others; fitting an electric pump won't solve the problem any more than fitting PAS will "cure" a partially seized rack.
Before drilling a hole, you could simply run with the cap off for a while (not with more than 5 gallons in the tank though, ideally). If that solves the problem, then you'll have narrowed down the possible list of causes of the trouble, if not, then you still would, since that'd be one less thing to cause it.

ok, so maybe if i take the cap off, go for a drive... if it still happens... whats next? seeing as its a new pump and new rubber piping?
Thanks

Sure is an odd one, but by the ongoing process of following the fuel supply all the way upstream, then perhaps there's a blockage in the breather pipework inside the boot? Actually no, scrub that, running with the cap off (and don't get caught doing so) would eliminate that too.
Just to recap; did you replace every one of the rubber connectors between the steel sections of the pipe?
Is there a smell of fuel in the boot?

breather pipework ...

I replaced all the rubber bits that i could see... which i think was 3 or 4 pieces. everyone keeps on about there being a rubber part above the gearbox??? but i don't think there was any rubber part there.

that i know of there is no smell of fuel in the boot.

Thanks

Just my tuppenceworth.....

One of the advantages as I see it of the electric pump in the boot and bypassing the mechanical pump is there's less heat transfer into the fuel, ( The mech pump gets pretty hot, preheating the fuel ?) reducing the potential evaporative stalling on a hot tickover. My Armstrong Siddeley was transformed driving in hot slow traffic after swapping from mech to leccy pump.

Also, re the inertial cutout. It worked for decades on many, many cars when mounted in the engine bay or front footwell even in the event of a rear impact. The shock is transmitted through the body easily enough. The inertial switch on my AS is off an Alfa of some kind ( Fiver off Ebay ) and mounted to a plate along with the relays I put in for the headlights n stuff, the plate in turn mounted to the innner wing. If anything it's a tad too sensitive. Cuts the bloody pump when bumbing off a curb, which took a while to work out the first time it did it?

trampintransit wrote: ↑Sun Dec 18, 2022 7:03 pm Just my tuppenceworth.....

One of the advantages as I see it of the electric pump in the boot and bypassing the mechanical pump is there's less heat transfer into the fuel, ( The mech pump gets pretty hot, preheating the fuel ?) reducing the potential evaporative stalling on a hot tickover. My Armstrong Siddeley was transformed driving in hot slow traffic after swapping from mech to leccy pump.

Also, re the inertial cutout. It worked for decades on many, many cars when mounted in the engine bay or front footwell even in the event of a rear impact. The shock is transmitted through the body easily enough. The inertial switch on my AS is off an Alfa of some kind ( Fiver off Ebay ) and mounted to a plate along with the relays I put in for the headlights n stuff, the plate in turn mounted to the innner wing. If anything it's a tad too sensitive. Cuts the bloody pump when bumbing off a curb, which took a while to work out the first time it did it?

Can't you achieve the same by just mounting the mechanical pump with the longer arm? The spacer block should reduce heat transfer from the engine block.

cleverusername wrote: ↑Mon Dec 19, 2022 10:20 am

trampintransit wrote: ↑Sun Dec 18, 2022 7:03 pm Just my tuppenceworth.....

One of the advantages as I see it of the electric pump in the boot and bypassing the mechanical pump is there's less heat transfer into the fuel, ( The mech pump gets pretty hot, preheating the fuel ?) reducing the potential evaporative stalling on a hot tickover. My Armstrong Siddeley was transformed driving in hot slow traffic after swapping from mech to leccy pump.

Also, re the inertial cutout. It worked for decades on many, many cars when mounted in the engine bay or front footwell even in the event of a rear impact. The shock is transmitted through the body easily enough. The inertial switch on my AS is off an Alfa of some kind ( Fiver off Ebay ) and mounted to a plate along with the relays I put in for the headlights n stuff, the plate in turn mounted to the innner wing. If anything it's a tad too sensitive. Cuts the bloody pump when bumbing off a curb, which took a while to work out the first time it did it?

Can't you achieve the same by just mounting the mechanical pump with the longer arm? The spacer block should reduce heat transfer from the engine block.

I don't think it's an issue at most cars with a mechanical pump. I think the float bowls hanging above exhaust manifolds would cause more trouble when too hot fuel does cause problems.

Jeroen

the mechanical pumps can supply more than enough fuel, even for double 45´s Weber carbs.

a dolly, fully loaded, going uphill, in winter, with throttle fully open might have a consumption of 12mpg.
and the original pump can supply that.

a "real" reason for fitting an e-pump is to prime the (dry) float-chamber, as often our cars arent used on a daily basis.

for such pre-priming a simple pump, routed in line with the original pump is more than enough and it could be also wired without inertia-switch. just use a simple toggle switch. if you dont want to install an extra toggle switch, use the rear-screen switch. here just a sample of a pump which could be used (quick search):
https://www.ebay.co.uk/itm/151711108040 ... R7rtu9arYQ


this said....lets look over the edge:

all the typical alfa-romeo´s from the 70ies (Giulia, Spider, GTV, GT/J) had double 40ies webers/dellorto/solex fitted. all those cars came from the factory with a mechanical fuel-pump.

around 25y ago i was owning a standard 1600 Giulia, my mate a giulia with a tuned 2L engine..we went to Nürburgring.
before we went on the track (Nordschleife) ...we topped-up the fuel to max...drove 2 laps ( 2 x 21km)...an re-fueled again:

the consumption on my Giulia was 11mpg, my mates 9mpg.

One of my 1500HL dolomites started to cut out due to fuel starvation and I suspected that air was being drawn into the supply line so I replaced all the rubber joint sections but it continued. In the end it turned out to be a very small rust hole had developed in one of the bends in the metal petrol pipe that goes up over the rear axle. As this point it is above the fuel level in the tank fuel did not leak out at any time, even when the pump was working, as this was pulling air into the pipework. I can't explain how after an overnight rest the engine would start and run for a time. It did take me a long time to find the problem but once that bit of pipework was replaced with a length of micro bore central heating copper pipe the problem was solved. My recommendation is take this section out and check it for a rust hole or crack.

Some OHV triumphs seem to suffer with hot fuel issues, and electric pumps see
m to help.
I have wondered about having a (restricted) return pipe from the carbs back to the tank, so fuel doesn't spend too long sitting in pipework in the engine bay. I "think" some carb equipped cars used a system some years ago. Maybe fords?