fuel pump upgrade.Why?

[nospark]

The 260z came with a supplementary electric fuel pump. Why did Nissan do this? Was it because they found the 240z mechanical pump setup to be deficient in some operational circumstances and this was the best time to introduce an upgrade ? Or was it because technical differences in the 260z engine required the extra fuel boost?
Just curious.

 

[Rob Gaskin]

I don't know the 'official' answer but in my experience the mechanical pump can deliver the fuel ok but after a period on non-use it takes a while to fill/prime the carbs. Electric pumps can pump without the engine turning over.

 

[nospark]

I typically use my car every 7 to 10 days and the first start up typically takes about 20 seconds before it catches and fires up. For the rest of the day it then starts immediately. So I can see what you are saying.

 

[AliK]

I think it read somewhere they had them for certain hot climate markets but bit for the UK cars.

Cue Albrecht or RichieP

 

[Stockdale]

My early 260Z isn't fitted (and as far as I can tell never has been) with any supplementary pump. Just the mechanical unit. Seems to work fine with starting within 5-8seconds from cold and no hesitation when driving. I always thought that it was only later model 260Zs that had the supplementary pump but may be mistaken.

 

[andrew muir]

Thats almost exactly the same as mine!
About 15 seconds to get it to fire up after that it starts one the button till laid up for more than 24 hours.

I typically use my car every 7 to 10 days and the first start up typically takes about 20 seconds before it catches and fires up. For the rest of the day it then starts immediately. So I can see what you are saying.

 

[SeanDezart]

The Z was a world car built for different climates AND there was a carb change.

I believe that you have touched both reasons :

easier/quicker starting and especially in hotter climates

I don't know from which production year the electric pump was fitted as OEM or whether is was certain target models/countries.

 

[Albrecht]

Auxiliary electric fuel pumps were fitted in certain markets from almost the beginning of production (on HLS30-U 'Datsun 240Z' for example) as part of the battle against fuel percolation.

PS30 Fairlady Z432 and PS30-SB Fairlady Z432-R had electric pump (no mechanical pump on S20 twin cam engine) and the 'L' shaped bracket mount and mount location on the right hand rear transfer link brace link was carried over onto other models.

Electric pumps helped to keep fuel line pressure up, which helped the fuel percolation issue somewhat. As engines were gradually set to run hotter (for lower emissions) the percolation issue got worse...

 

[SeanDezart]

Thanks.

Never seen them on any HLS30s - from when were they fitted on RLS and GRLS30s please and on all of them from day 1 ?

 

[Albrecht]

It's all in the factory parts manuals...

 

[SeanDezart]

Oh jolly good then...........!

By design, mine will also have an electric fuel pump