Whining fuel pump - what does it mean
 

I have been getting on and off over last few months a loud whine - can be heard inside and outside the car - from the o/s/r wheel area. Also the area where the fuel pump lives.

Mine is a 94 wagon JDM classic scooby, and had a Walbro 255l/hr fuel pump about 3 - 4 years ago.


It used to whine when I was low - i.e. on E on gauge - of petrol but now does it now and again even if full.


Is the pump worn out, or getting airlocked?

I had the odd "fuel starvation" when booting hard and on under 1/4 tank ...


If it is shot, what's the best drop in replacement - Walbro, Bosch or other?

Thanks

there isn't another drop in replacement to replace the wallbro. However the bosch can be fitted with some small modifications. best to do a search for bosch fuel pump. Got a bosch 909 fitted on my P1.
ken

Walbro is still best VFM upto 450bhp..

Simon

Thanks Ken.

Hi Simon! ;)

Really wondering is the fuel pump now had it and if I need a new one ..

What mods are needed for the Bosch, as I have seen the higher powered cars using one or two of them ... I have been happy with the Walbro though and it's an easy swap at a good price!


Neil

Mine wines all the time, sometimes I notice it more tha others - its done this for years. If you take the rear seats out its even louder
It doesnt seem to effect performance and the fuel pump is fine. You'd soon know about it if it was knackered!
On Track I get fuel starvation issues under a third of a tank........

Cheers guys.

Suppose I should ask, as Simon mentions the Walbro is OK upto 450 bhp.

I have a calculated 430-440 BHP based on the calc for 4 ( no. injectors ) x 850 (flow rate mm/min ) x 72% ( injector duty max ) divided by 5.5 ( mls per hp ) . TD05-20G at 1.65 bar - 1.70 bar boost. Broke the gearbox recently after 2 years of 363 bhp/325 lbft!

Is this calc about right?

It was spot on for the last turbo / injectors at 360 when measured 3 times on 2 rolling roads over 18 months at 363 bhp/325 lbft. ( 550 injectors at 91% duty, TD05 @ 24 psi )

I thought that the 20g would only get you to 380-400hp, with a few of exceptions running 420bhp with octane booster?

Need to get it on the rollers when it's all sorted.

Had 363 offf a TD05 std turbo with 90 degree inlet. High boost from it means more air = more power!

No way it will get that power - not 'real power' but fantasy numbers
Then again I dont want to comment much more than to say at best its about 380-400 (on optimistic rollers) as I dont want it to go into a Turbo Thread

No turbo thread arguments - I just run high boost to get more air in the engine, . Certainly more power / torque there now thru the rev range than the measured 363/325 lbft on the old turbo!


Is the calc I posted still avout valid ..?

Only posting the "power" to see if fuel pump may have been at it's limit ...

What mods needed on the Bosch in tank fuel pump?

Who does the best price now on the Walbro in tank 25 l/hr furl pumps?

I'm going down the Bosch route as my uprated pump, although not knackered, just cant flow enough above 5500 revs, the pressure drops by .5 bar.

I've sourced the pump from Harvey (:thumb:) and list of bits required to fit it from Bob Rawle (:thumb:) but wont be fitting it till early next year as I've got to do MOT, engine mount changes etc first. The bits for fitting cost abotu £50 from Demon Tweeks, they're good in that you'll prob just need to state you're fitting a Bosch ### to a scoob and they'll send you the parts.

Swiss

What was your uprated fuel pump - a Walbro?

Seems a lot of mods for the bosch pump!
The "big power boys" seem to use in tank pump and swirl pot with 1 or 2 bosch pumps to feed the fuel rails ...!

Yep, Walbro...its only had the whine once or twice this year and works well but the drop off from 5500 revs is now causing issues. I dont need two pumps or anything like that as I'm heading for 500 bhp, no more, so the single Bosch will do nicely. Not sure what the fitting will be like as I've never taken a pump out before but I've got a guide and pic from Bob (:notworthy ) to help me along.