Fuel Filter and Pump Recommendations with conversion from FI to twin carbs

Started to get fuel starvation issues again at about 1/4 tank so Have move pump higher up to see if any better. With pump in stock location and long hose lengths maybee gravity feed to the pump inlet just can’t keep up as it had primed and run ok with full tank n more pressure..

 

Malpassi filter bowl is not always full of petrol and is not meant to always be full of petrol.

Is what I was told

 

Yeah That’s probably right. after I broke down in the services I Refitted the Malpassi in the lower position and it filled back up Nearly to full and all looked ok. Then it cut out again on way home after about a mile, pulled off fuel hose To carbs and again bone dry. Should of just filled back up with fuel!
Hopefully will be ok now

 

I would move the obviously struggling pump higher. Job done. Why fight the obvious?

 

Fingers crossed, just gotta re balance n tune carbs again as it’s now very rich and stinks! was also back firing slightly on motorway when lifting off throttle

 

Happened again whilst trying to tune carbs, no fuel pressure and pump making a racket but still going...

Recon the Slosh tank inlet holes r Partially blocked so anything below 1/2 tank and slosh tank empties out completely whilst tank still 1/2 full. Then gradually fills back up after about 1hr!
New tank on order from Schofield (With £30 off )

 

If you fitted a cutoff solenoid valve before the pump or simply put the pump on the chassis rail, below the tank you would not be ever calling on the pump to prime on air.

4psi is about 3 metres of lift of fuel on the outlet, so its the input suction that is the issue. if you arrange it so air gets in the inlet of the pump thats what stuffs you.

Move the pump down..

 

I had the pump down on rail in original position and same thing happened . Pretty sure it’s fuel starvation!
I didn’t realise there’s a small tank within the large tank. I thought it was a baffle!
I Think the small lower inlet holes to small tank are partially blocked. Causing small inner tank to empty when below 1/2 tank, (maybee just FI. Busses have this type of tank?)Also think the fuel outlet fitting is flush inside tank, IE no stand pipe.
Maybee my Fuel inlet/outlet pipes are just the wrong way round?

 

I'm happy, the pic shows it couldn't really be fitted much lower!

 

The pump does virtually nothing anyway, the float chambers are more or less at the same level as the bottom of the tank and it should work higher or lower. The problem is elsewhere and if he’s connected the pump suction to the FI return to tank that could be it - but I don’t know how a FI tank is arranged internally.

 

yep supply and return both within stupid little bowl with no standpipe ......at least now I know!
Supposedly you can replace tank with eng still in (type 4 only!) we will see!

 

Seems like you would have been better off simply sorting your FI (non-issue).

Seems you have taken a massive step backwards

 

Not really because I need it to be realiable !

 

You broke down and then changed it all to carbs and by what I’m reading have ‘broke’ down several times due to your new setup = unreliable.

FI is Superior to carbs and once understood you would have confidence in it. Your breakdown might have been unrelated to your FI.

 

What's with the heavy wiring that belongs on the starter solenoid flapping around the tank outlets? Is it just the photo?

 

Pretty sure that's the feed to the dual relay (when on FI) that powers the relay during cranking.

The tank is obviously full of crud, look at the rust in the filter

Sent from my Pixel 4 using Tapatalk

 

Yes breakdown was due to fuel starvation issues but fuel injection system was also very degraded with all rubber boots perished And idled at 2000 (bus had sat for 20 od years) Carbs was simply easier until I can overhaul engine,/rebuild bigger tuned engine, might Even go scooby yet, but without Malpassi and fuel px gauge id never of known what’s wrong!

 

Yep factory wiring to fuel pump via relay, still in use but yes wants re routing somehow really

 

Probably the pesky tank as you suggest! Random tank outlet blocking is very difficult to diagnose with any confidence.