Jump to content

Lucas fuel pump on my 72 CP


Recommended Posts

Hi all

this might be a regular (old chestnut) but your opinions are as always most welcome and valued,the fuel pump on my car is as far as I know original and it is also noisy,the noise even goes up and down when I dip the clutch or operate the indicators!! Revington TR have quoted me to fit a new set up (ouch)but I have this nagging feeling that although I don’t do many miles it’s never let me down and lm wondering if I am changing it for a possibly less noisy set up and not much more.As i have been considering this for a while and frankly getting nowhere any opinions would be great.

regards nige

Link to post
Share on other sites

From the up and down noise I would go initially for electrics, which alternator is fitted, have you checked the cut out switch for high resistance, may need a new thicker wire with a relay to the pump, also pump earth.  Get this bit right first then we can look at other items.

John

Link to post
Share on other sites

+1 for John’s hints. 

I fitted a 55 A Bosch (as used on older Ford Escorts etc), and a dedicated relay for the pump to the high current of my Bosch pump does not run over the ign. switch. This should eliminate the low voltage when idling, which causes the pump to change revs.

You Lucas pump will run at a much lower current; maybe have it reconditioned and fit a new filterelement and see what that brings? Certainly cheaper.

Waldi

Link to post
Share on other sites

I had my original Lucas pump overhauled and reconditioned by Neil Ferguson. Runs much quieter!!

Steve

Link to post
Share on other sites

Nige,

I have the Lucas pump set up. I think mine is pretty original and is 1969 car. I hear the pump when i turn the ignition on but once started i don’t hear the pump. The car was overhauled / put back on the road in early 1990’s but not sure the pump has been touched since. Filters changed regularly but nothing else. Touch wood I have been lucky, and it runs well presently. Reasonably smooth at idle, and good pick up on acceleration. I doubt i have the original power from engine but it is pretty good. I’ve also run in UK / France on hot days without any issues. I can’t see justification for changing - at least while it is running like it is. I guess there are good pumps and bad ones, but the design must be good with its age. Anyway, just my view and experience to date (hopefully I’m not testing fate!).

Link to post
Share on other sites
4 hours ago, nigelcurry said:

Hi all

this might be a regular (old chestnut) but your opinions are as always most welcome and valued,the fuel pump on my car is as far as I know original and it is also noisy,the noise even goes up and down when I dip the clutch or operate the indicators!! Revington TR have quoted me to fit a new set up (ouch)but I have this nagging feeling that although I don’t do many miles it’s never let me down and lm wondering if I am changing it for a possibly less noisy set up and not much more.As i have been considering this for a while and frankly getting nowhere any opinions would be great.

regards nige

Pump overhaul might be on the cards.   You van strip ant fit new carbon brushes yourself.    Same as TR6 wiper motor with the offset brush removed.   Is the pump power supply as original or through a new dedicated relay controlled supply?   Check voltage at pump when ticking over.
Is there a voltage drop across the two terminals of the inertia switch?   Fix with new power supply to pump with relay actuation using inertia switch to only cut out the relay and main power to the pump in the event of an impact.

Clean and renew the earth and power supply at the pump.   Those bullet connectors corrode.

 

Link to post
Share on other sites

My wiring wasn't up to much, so I fitted a separate fused 12v feed from the battery, (although this affects the ammeter reading), into a relay that is switched by the original ignition supply to the pump. 

But for sure the motor might need an overhaul to make it quieter. 

Gareth

Link to post
Share on other sites
25 minutes ago, Mk2 Chopper said:

My wiring wasn't up to much, so I fitted a separate fused 12v feed from the battery, (although this affects the ammeter reading)

Better to wire it direct to the alternator output, the other side of the ammeter, since that is where the current comes from when the car is running. The way you have it, the ammeter carries the pump current all the time hence the incorrect indication.  

Link to post
Share on other sites
15 minutes ago, RobH said:

Better to wire it direct to the alternator output, the other side of the ammeter, since that is where the current comes from when the car is running. The way you have it, the ammeter carries the pump current all the time hence the incorrect indication.  

Thanks for that Rob,
that’s another job on my list because I have a feed to an auxiliary fuse box connected “wrongly”.

Cheers,
Waldi

Link to post
Share on other sites
21 minutes ago, RobH said:

Better to wire it direct to the alternator output, the other side of the ammeter, since that is where the current comes from when the car is running. The way you have it, the ammeter carries the pump current all the time hence the incorrect indication.  

Brilliant Rob, I'll correct my mistake. Thanks

Gareth

Link to post
Share on other sites

If you do decide to strip the pump, its easy enough to do. If its never been apart its likely to be full of carbon dust from the brushes & will need a good clean. Check the windings aren't burnt & the commentator is serviceable. Both of these can be carefully cleaned with contact cleaner. Do a resistance & insulation test. All the service info can be found at vitessesteve.co.uk 

 Don't bother with the pump overhaul kit-waste of money in my opinion. The brushes are wrong orientation & the screws they provide are incorrect. Source them yourself (amazon/ebay etc) & buy a new fuel seal (you'll need a one) from Neil Ferguson.

If you're not confident then get an exchange pump from Neil.

Alan

 

Link to post
Share on other sites

In my kit - nothing for the pump apart from 3 'O' rings for pump to motor. The other bits were brushes (copper lead incorrect orientation & requiring soldering), 2 brush springs (incorrect rating), 3 screws (incorrect thread), a grommet for the power supply wires & a fuel seal are the motor. In my experience, not fit for purpose - typical poor aftermarket parts. I reused my springs & screws & bought new brushes elsewhere. Oh and the only bit I really needed, the fuel seal, was missing from the package !

Very poor value for money at around £35 or so.

Alan 

Link to post
Share on other sites
10 hours ago, RobH said:

Better to wire it direct to the alternator output, the other side of the ammeter, since that is where the current comes from when the car is running. The way you have it, the ammeter carries the pump current all the time hence the incorrect indication.  

Hi Rob 

I'm literally at the stage of running a 12v feed to the auxiliary fuse box/relays to include the fuel pump relay under the dash from the battery +ve. Given what you have just said would I be correct in understanding that it would be better to take a feed from the smaller brown wire from the alternator going to a spare spade on the  "white connector block" attached to the inner wing (1969 UK PI) to feed the auxiliary fuse/relays?

Just because I'm no auto electric guru and want to better understand. What's the purpose of the Thick Brown/White and the Brown Wires from the alternator. Why not just one 12v output wire? 

Thanks 

Andy

Link to post
Share on other sites

The answer is going to depend on what alternator you have Andy.  It sounds as though your car may have the later ACR type with three connections only.  If so then yes connect to one of the output leads from the two large spade terminals on the alternator - it doesn't matter which.  

If there are two output wires and one wire is larger than the other it may just be a legacy of when the change was made to an alternator with a higher output current. 

BUT If your car still has the original type alternator with five connections you can't do that.  On those the thin brown wire is a voltage sense input to the regulator,  not an output. 

If you are unsure, post a photo of the connections. 

Link to post
Share on other sites
18 hours ago, RobH said:

The answer is going to depend on what alternator you have Andy.  It sounds as though your car may have the later ACR type with three connections only.  If so then yes connect to one of the output leads from the two large spade terminals on the alternator - it doesn't matter which.  

If there are two output wires and one wire is larger than the other it may just be a legacy of when the change was made to an alternator with a higher output current. 

BUT If your car still has the original type alternator with five connections you can't do that.  On those the thin brown wire is a voltage sense input to the regulator,  not an output. 

If you are unsure, post a photo of the connections. 

Hi Rob 

New Lucas IIRC 45A Alternator/plug. I'm simply more or less copying the old loom which was three wires;

Thick Brown/White to Ammeter - (now a thick Brown.)

Slightly thinner Brown - to white connector block in pic.

Thin Brown with Yellow trace to ignition light (original loom had a loop which I've discarded) 

So as per your original post is it best to take the supply to the new auxiliary fuse/relays from the white connector block rather than direct from the battery to ensure a more accurate ammeter reading?

Dare I ask another question:ph34r: To take the load off the ignition switch using an appropriate relay (WOSP starter) am I correct in thinking the White/Red carries the current through the switch to the starter solenoid. So using the W/R as the trigger for the relay is the way to go? I can't find a 1969 TR6 circuit diagram where this has being done. Is it worth doing?

Thanks

Andy  

 

IMG_2190.jpeg

IMG_2191.jpeg

 

IMG_2195.jpeg

Edited by PodOne
Pic de-rotation
Link to post
Share on other sites
31 minutes ago, PodOne said:

So as per your original post is it best to take the supply to the new auxiliary fuse/relays from the white connector block rather than direct from the battery to ensure a more accurate ammeter reading?

Yes that's right. The thin brown wire is an output from the alternator so using that for the supply to the pump is the correct thing to do. That way the pump current does not go through the ammeter.  The meter will only register current going into and out of the battery and will read zero most if the time as it is supposed to, rather than showing a spurious 'charge' which is actually being drawn by the pump. 

As you say, the white/red from the starter switch is the correct wire to power a relay coil for the WOSP starter. 

Link to post
Share on other sites

I never realised the white connector block was the supply from the alternator to the starter/battery and the fuse for the interior and boot lamps, all makes sense now. 

You learn something every day ;)

Gareth

Link to post
Share on other sites
47 minutes ago, RobH said:

Yes that's right. The thin brown wire is an output from the alternator so using that for the supply to the pump is the correct thing to do. That way the pump current does not go through the ammeter.  The meter will only register current going into and out of the battery and will read zero most if the time as it is supposed to, rather than showing a spurious 'charge' which is actually being drawn by the pump. 

As you say, the white/red from the starter switch is the correct wire to power a relay coil for the WOSP starter. 

Thanks Rob your help is much appreciated.

Andy

Link to post
Share on other sites
7 minutes ago, Mk2 Chopper said:

I never realised the white connector block was the supply from the alternator to the starter/battery and the fuse for the interior and boot lamps, all makes sense now. 

That block seems to originally have been associated with a different type of alternator Gareth, and may have been re-purposed in different ways depending on how the changes to the wiring were made to fit a later type.  The advice above is based on the specific photos of Andy's car.  Don't assume they are all wired the same. 

Link to post
Share on other sites
9 minutes ago, RobH said:

That block seems to originally have been associated with a different type of alternator Gareth, and may have been re-purposed in different ways depending on how the changes to the wiring were made to fit a later type.  The advice above is based on the specific photos of Andy's car.  Don't assume they are all wired the same. 

No, for sure I'll check how mine is wired, but it looks similar from memory. Actually I may have a picture. Yes here it is:

20220512_194901.thumb.jpg.3681a2e6fdcb50872c0c9d82b0a240e6.jpg

Think the first thing is scrape the paint off it!

Gareth

Edited by Mk2 Chopper
Link to post
Share on other sites
5 minutes ago, ntc said:

I would never wire the fuel pump feed from the alternator.

Why is that Neil?  It's the only way to do it correctly if the car has an ammeter. 

If there is no ammeter then the alternator and battery are connected together so in that case you have no option anyway. 

Link to post
Share on other sites

OK so I've checked my wiring and the wires going into the white connector block are the 'other side' of the ammeter, so connecting to there still makes for an incorrect reading.

On the wiring diagram there is a brown wire coming off the starter (other side of ammeter as above) that goes to the white connector block and on to the interior light/ horn fuse. So I really need to connect to the thick brown/ white wire at the alternator to be on the correct side of the ammeter, as this is connected to the ammeter and from this same connection goes to the ignition switch, which would normally have gone on to feed the pump power. 

Edit: 

Tested the pump connected to the alternator output and ammeter works as is should, have ordered the 9.5mm (in new money) lucar flag connector to use the spare slot on the alternator. 

Gareth

Edited by Mk2 Chopper
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.