Mechanical to electric fuel pump conversion.

[bl1300]

I've recently been having problems with my DAF 44 with fuel starvation. I've tried a rebuild kit in the existing mechanical fuel pump but i'm still getting such a weak fuel supply she is barely drive able. Having tested the supply after the pump its literally only dribbling.

Now this leads me to think either the cam lobe the drives the fuel pump is worn, the pushrod bent or the cam lever in the base of the pump. The simplest solution to me seems to be to bypass the mechanical pump and fit and electric.

The car is only 844cc single carb so the pump can't be overlly powerful or it will overwhelm the carb and flood the engine. I was thinking either an SU pump from a Morris minor or a facet pump.

What would you recommend as a suitable part. The car is 12V so easy there but does not have provision for an electric pump so the less bulky the better.

Paul

[omega]

if you can find a bedford rascal van [1000cc] they have a electric pump.its mounted underneth near the tank

[davemnw]

You'll need something with a fairly low delivery pressure (around 5psi max). I've got a facet pump on my VX (with twin strombergs) like this one and would never go back to the old mechanical setup. Easier starting after she's been stood for a while, no more hot starting problems, and much smoother running in hot weather. It's only a couple of inches square, so easy to find a spot for it. Instructions say it needs to be near the tank, but it works fine up in the engine bay too (just took a while to prime when it was first installed). Webcon do a similar thing with a fitting kit too.

[steveo3002]

Jan 18, 2015 19:22:27 GMT davemnw said:

You'll need something with a fairly low delivery pressure (around 5psi max). I've got a facet pump on my VX (with twin strombergs) like this one and would never go back to the old mechanical setup. Easier starting after she's been stood for a while, no more hot starting problems, and much smoother running in hot weather. It's only a couple of inches square, so easy to find a spot for it. Instructions say it needs to be near the tank, but it works fine up in the engine bay too (just took a while to prime when it was first installed). Webcon do a similar thing with a fitting kit too.

does it make much noise?

encouraging to hear they work in the bay , id heard they fail quickly if not down near the tank level

[docjohn]

Whatever pump you use, and the Facet ones are fine, I would suggest thinking about a couple of other things. A relay is a really good idea, and a switch is useful both as a security feature and for when you are working on the car and need the ignition on when the engine isn't running. Electric pumps are quite sensitive to any debris from the tank, so I'd recommend an inline filter before the pump. You are quite right to ask about fuel pressure, and I always use an adjustable pressure regulator so that you can match your carb's needs. All together that'll cost about £100 but is easy to do and will be very reliable.

[davemnw]

It's mounted on a couple of small rubber cotton reels low down on the inner wing. There's a faint humming noise when you turn on the ignition but with the engine running it's inaudible. Had it for 5 years now (summer use only) and it's still working fine.

[MrSpeedy]

As suggested, one of the small square solid state facet pumpds would be ample for your application.
I would also suggest fitting a pressure regulator of feeding a carb more used to low pressure.

When I converted my Vitesse to electric from mechanical I initially had the float chambers curse word fuel out. A cheapo 'Sytec' regulator set at 2.5psi solved all the issues

[Rich]

I fitted one of these to the MGB to replace the failed SU pump.
www.ebay.co.uk/itm/FACET-ELECTRIC-FUEL-PUMP-ULTRA-LOW-4PSI-NO-REGULATOR-REQUIRED-4-CLASSIC-CARS-EO-/400822185781?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5d52dd2f35
No regulator, has a built in pre-filter, very small and low current draw. No issues with it at all. We are going to use one on our diesel buggy to keep the filter pot full as the tank doesn't gravity feed as well as we had liked. Good little things.

[bl1300]

Fully intending to fit with a cut of switch and relay. It would be daft not to. The way it was going to be fitted was so that both the ignition and a hidden key switch must be on to activate the pump. The standard setup has no security on whatsoever. I can and have started her without the key without damaging anything and using two strands of wire so extra security is a big bonus.

I've ordered a pump now a 3 to 6 psi jobby like mentioned above. Will be mounting the pump on the front inner wing in the engine bay as the lines there are lower than the tank anyway so shouldn't be a problem for priming. I will also move the inline filter to before the pump as its currently fitted on the high pressure side of the mechanical pump due to the bloody thing not being able to draw through it.

[taurus]

I used a Mini pump on my Triumph 1500, worked a treat. It's well worth doing.

[bl1300]

Conversion complete.

Have left the mechanical pump in situe but blanked off the pipes and bypassed it's a pain to remove.

Electric pump is mounted low on the inner wing with a fuel filter before it and the thing only cost £12. Wiring is simple she is relayed with the activation circuit running off the ignition with a hidden key switch for extra security. So she effectively now has an immobiliser in the form of a fuel supply cut off.

As to difference. No more missfire or hessitation and she is now driveable. Has highlighted another problem though in a poor charging system as she is only just coping with the extra drain of the pump.

[romfordman]

mechanical pumps are ok when fully functional. had mine revamped with a service kit. still have slight issues with hot restarting due to gas vapour bubbles. tried fuel pump electric facet type.worked a treat but every now and again failed to function! may just be a dodgy pump ..or possibly it was trying to apply too much pressure and over heated. so when 'cool' started again. went back to mechanical. an inline pump as used on say Fords etc with 12v and low pressure supply is likely my best bet as a late fix if still unhappy with my current mechanical one. ( rover p6 v8 auto)

[hario]

For information, all modern electric fuel pumped cars have a tilt / knock switch inline with the ignition live which cuts the 12v supply in an accident for safety.

Imagine if you crash and the car flips upside down and the fuel pipe is severed, the pump will continue to pump petrol over the car and you (until the ignition is switched off).

I incorperated this safety feature when I facet pumped my classic Mini because it was a death trap to begin with and most crashes resulted in the occupants being pinned inside.

Think happy thoughts..

[Rich]

Feb 3, 2015 16:20:13 GMT hario said:

For information, all modern electric fuel pumped cars have a tilt / knock switch inline with the ignition live which cuts the 12v supply in an accident for safety.

Imagine if you crash and the car flips upside down and the fuel pipe is severed, the pump will continue to pump petrol over the car and you (until the ignition is switched off).

I incorperated this safety feature when I facet pumped my classic Mini because it was a death trap to begin with and most crashes resulted in the occupants being pinned inside.

Think happy thoughts..

It's a good point, when I rebuilt the MGB fuel system when it goes to injection, I will be pilfering an inertia cut-out switch from the next scrap car we have in that has one. I meant to do it ages ago but yea. It was built like that. Interestingly enough, most modern cars don't have them any more, the red 'pop-push' under bonnet ball bearing cut-outs are a thing of the past. It's all done with crash sensors linked the the SRS.

[hario]

Yeah intertia-cutout thats it!

I remember we used to rob them from saxos and rubish little things like that, so it's a mixed blessing they're all dead now.

[chrissyb]

Many cars didn't use the inertia system, most cut off their pumps when no ignition pulses were detected which was probably sufficient.