504 TI fuel pump replacement

[Wilko]

My original pump is leaking around the DC connector and had been “repaired”
with Araldite by a previous owner. I ordered a replacement pump from La’Adventure quoting the original part number 1450.41 which looked identical to the original in the parts breakdown. The pump I received, is nothing like the original and does not have a pressure regulator. The spec on this pump has an operating pressure of 1 Bar or around 15 psi, so it should not need pressure regulation I’m thinking. It’s recommended that non return valves be fitted in the flow and return lines, a flow restrictor in the return ( possibly to create some back pressure) and finally that the pump be located BELOW the tank level, yet they quote a maximum suction lift of 500mm with full lines. My thoughts are that it’s not practical or desirable to locate the pump in such a low and unprotected location and would prefer to locate the pump pretty much in the same location as original. Has anyone used this replacement pump and found it to be satisfactory? Grateful for any help.

 

[BP505v6Turbo]

Hey Wilko.
You can pull apart Ti fuel pumps, I've fixed siezed ones, pretty easy, if you have another one or others you can make 1 out of 2. Have a battery near by when pulling apart to test it on the bench. Also lots of CRC to lubricate.
You'll have to undo the locking parts in the body to get into it.
Good luck finding a new pump there not a thing to be found.

Hope you work it out.

Cheers BP

 

[Andrew Watkins]

I have a similar. Pump - Bosch, from a Commode - in the 404 which is running KF2 injection and it works well without pressure regulator. My recent (past?) issues with overfuelling are not pump related

Mine is installed in the 404 just in front of spare wheel mount and is well out of the way, also at bottom of tank level(ish). Can‘t remember exactly what the underside of a 504 looks like but there may be a similar niche

Mounting is old datysun 280Z mount, which fits perfectly and is nicely rubber insulated.

I don‘‘t have non return valves etc installed, although the KF in the 504 is a bit different

The KF injectyion doesn‘t need the super high fuel pressure needed by modern junk

Andrew

 

[BIGRR]

Pump specifications can be found here "504.org" under Technical Information Engine Chapter 1

 

[neil s]

Very vague memory that it is a VL commodore pump that will work??

 

[julian c b]

I have a VL commodore pump in my 504 cabriolet and have had no problems .It has higher pressure than original but the unused fuel just returns to the tank as it did before

 

[Wilko]

Thanks guys for your helpful hints. I have fitted the new pump and it’s somewhat noisy. The installation instructions state that a flow resistor be fitted in the return line. By clamping the return line partially the pump is a lot quieter indicating that it could be cavitating due to low pressure ( not sufficient back pressure). Does anyone know where I can obtain such a device? The pump’s operating pressure is around 15psi and the Keugelfischer injection pump operates at around 17 psi so the return line should be restricted to allow the pump to maintain the correct operating pressure.

 

[robs]

I had noise problems when I fitted fuel injection from a Falcon to my 604. The injectors only wanted something like 15 psi, but the pump could deliver more like 60. The pressure regulator was struggling to send the excess fuel back to the tank. I ended up fitting a cheap adjustable PWM controller on the pump power supply and that let me slow the pump down. I adjusted flow so that there was enough returning to the tank to be sure the regulator was in range (something like 250 ml per minute down the return line). Pretty sure something like that would do the business for the TI.

There's a picture of the PWM unit halfway down the page linked here. Nine years later and it's still working fine.

 

[GRAHAM WALLIS]

Leave the old pump in place without power and run the fuel from the new one into it. The pressure regulator on the old pump will continue to function.