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Re: Dolomite 1850 fuel pump problem

Posted: Tue Jun 01, 2021 9:08 am
by davidmorr
Thanks for that. I can apparently get the same item here in Australia. Will have to see if anyone local has them.

I was quite surprised to see really elaborate pressure devices, going up to 160PSI. They even had gauges on them!

Re: Dolomite 1850 fuel pump problem

Posted: Tue Jun 01, 2021 3:48 pm
by Carledo
davidmorr wrote: Tue Jun 01, 2021 9:08 am Thanks for that. I can apparently get the same item here in Australia. Will have to see if anyone local has them.

I was quite surprised to see really elaborate pressure devices, going up to 160PSI. They even had gauges on them!
If you have a 2.5 PI Triumph engine in a TR6 or WHY they won't even run at less than 115PSI! Most modern EFI systems run at around 3bar (45psi) though you can boost this to 4 bar or so with an adjustable fuel regulator for a couple of extra horses. Much more than 4.5 bar will upset the idle (guess how I know)

You don't need one of these fancy devices though, as you only need to drop the fuel pressure from the 5-6psi that the pump is generating down to the roughly 1.5 psi the carbs need to run right.

I recommend a Sytec Pro-Flow like this one below.


Image

Steve

Re: Dolomite 1850 fuel pump problem

Posted: Thu Jun 03, 2021 3:06 pm
by davidmorr
Well, after managing to source a pressure regulator, at great cost, I managed to borrow a pressure gauge and discovered the pump was only putting out 2psi anyway! Certainly the SU carbs were not flooding.

So the car would idle nicely after that, perhaps a bit rough - too rich? But if I pushed the accelerator in, it would get up to about 1500rpm then either start backfiring or just slow down and stop. I pulled out the plugs and found that 1, 2 and 4 were a bit sooty, but 3 was not sooty and perhaps a little wet.

I am guessing an electrical problem, perhaps a bad spark plug or lead?