Sputters when running

R

rusty260z

New Member
Hi, from New Zealand
i had P6b previously, used it daily, but am looking into getting another one i known about for a while,
its going realtively cheap but has the following issue as described by the owner

"Sputters when running on main fuel tank - reserve works fine -"

would the fuel tank need to be drained and cleaned?
Fuel filter? or something eles,

thanks.
 
rusty260z wrote,..
"Sputters when running on main fuel tank - reserve works fine -"

would the fuel tank need to be drained and cleaned?
Fuel filter?
Click to expand...

Hello rusty,

Given it works fine on reserve, that would eliminate the filter from the equation, thus the likely origin of the problem is either a blockage in the tank at the point of exit for the main line, or a blockage in the actual line at some point before the reserve tap.

Ron.
 
I always thought there was a filter in the tank on the pickup for the main fuel supply ? Blow back down the fuel lines with compressed air and that should shift it ( or blow the filter off the pipe )
 
DaveHerns wrote,...
I always thought there was a filter in the tank on the pickup for the main fuel supply ?
Click to expand...

Hello Dave,

The filter on the pickup is actually on the reserve. The main outlet has no filter at all, but rises up some 2 or more inches from the base where as the reserve is essentially flush, hence the need for the filter.

Ron.
 
Thanks, ill talk to owner if tanks been drained at any time

slightly related qestion, my previous car, the reserve tank didnt work according to previous owner so never used it,
but how does the reserve tank work, does it fill it self, or have to actually fill it up, like main tank,
is the filler cap for reserve in trunk, cause the car i saw had one but there is no tank there, just empty space,
 
Hi Rusty,

There is no reserve tank as such, the reserve supply just draws from a lower level in the main tank and feeds via a separate line through the reserve tap which is cable-operated.

Many owners never use this facility, given that a 30-odd year old tap seal may (understandably) leak! I do use it (occasionally!) - but only because my tank sender unit is shot! :LOL:
 
wonder if the tap is sucking air when in the main flow position? this may cause inconsistant running.
I use the Reserve tap in my P6B pretty much all the time always have since 1987/8 when I got it, never an issue i just drive the car till it dies pull the reserve and drive for under 30 miles( dont want to run it completely out, I hate having to walk) and refill, push the reserve in then repeat the process for every tank fill, as I said never yet a problem and I have never ever even looked at the tap (touch wood).

Graeme
 
One of the P6 experts told me the filter was on the main pick up ( or maybe some thing made of nylon to do with the fuel gauge ? ) I had the problem of the engine dying on main supply but running on reserve and a blast of compressed air down the fuel line (pump removed ) cured the problem . I never took the tank out to find out why
 
If it runs fine on reserve, but sputters on the "main" then the easiest thing to check (and has been known many times) is that when you push the reserve knob back in, that the tap in the engine is fully returning to the correct 'main' position. I suggest that you look under the bonnet and push the reserve tap to make sure it is fully home.

I bet that will solve your problems.

Brian.
 
You would also have to ask if he keeps more than just a couple or 3 galls in the tank?
As if its kept too low then the main feed will suffer from low level and as it sloshes about it will suck air and splutter.
 
DaveHerns wrote,..
One of the P6 experts told me the filter was on the main pick up ( or maybe some thing made of nylon to do with the fuel gauge ? )
Click to expand...

Hello Dave,

I had a P6 expert tell me years ago that de dion tubes were only ever oil filled, and there was no such thing as a grease type... :shock:

I do have a brand new sender unit, and it is exactly the same as the design of the unit I recently removed from a P6B that I was dismantling. The main line supply pipe on the sender has no filter. Only the reserve has the gauze filter, and the reason being is that the former rises up 9.5cm inside the tank, whilst the latter is flush and thus more suseptable to picking up debris.

Ron.
 
Hi all,
on the point Daveherns made about the nylon in the tank, when the tank of my car was removed by a friend a few months ago he found nylon wrapped around the the sender, and this had entered the main pick up. It was not fitted to the new sender I fitted to the car. What is it for if it's not a filter? At the time the car would die on main line and then run on reserve for a while before dying.
Regards,
Dave
 
dmcsweeney wrote,..
he found nylon wrapped around the the sender, and this had entered the main pick up. It was not fitted to the new sender I fitted to the car
Click to expand...

Hello Dave,

Was the nylon wrapped around the sender that was removed from your tank deliberate or did it end up around it having been dropped in through the filler?

If it was the former, then someone at some point has tampered with it. The OEM sender units had no such arrangement on the main outlet.

Ron.
 
Hello Ron,
the nylon in the tank was actally fitted to the sender unit, rather than wrapped around it. It would have required removal of the float arm to facilitate fitting it. It was basically free to move up and down the vertical piece of metal that the float is hinged from. I have the unit in the boot of the car so i'll take a picture of it later when i get home, it looked like an original fitting to me but i'm probably wrong. Will post it later.
Regards,
Dave
 
I actually meant - one of the P6 "experts ". Not anyone on this forum , I can't remember exactly who
Whatever it was blocking the pick-up a few PSI from the airline shifted it and I could hear the air bubbling around in tbe tank.

I do see the logic in putting the filter on the lowest pick up point
 
dmcsweeney wrote,..
it looked like an original fitting to me
Click to expand...

Hello Dave,

Gee, well that is amazing. I do look forward to seeing the pics. Maybe Smiths were trialling such a device, but it never took off? Given the new ones that we have seen, and the used ones that I have along with no mention in the parts book listing of variations,...a mystery indeed!

Ron.
 
Lads,
appologies for the quality of the pictures.
75238158.jpg


79204554.jpg


89238435.jpg


59413358.jpg


The nylon is fairly well fraid but still in one piece around the copper conductor from the sender connection up to the unit that the float attaches to.
These loose fibres had been drawn into the main line on my car.
Regards,
Dave
 
Hello Dave,

That looks bizzare.... :shock: To me, it does not look like something that would have been placed there by Smiths. More likely I would think someone at some point has had a play with it, and it also looks suspiciously like fibre glass matting. It certainly appears to me as if it would be of no benefit at all as a filter, if indeed that was what its indended purpose was.... :?

In your pics, which are really good Dave, the main line with its lengthy extension rising up some 9.5cm and the reserve outlet covered by its gauze filter are both clearly visible.

Ron.
 
Ron,
what the photos may not show clearly is that the material forms a cylinder around the metal. It was not glued and seems to have been woven that way and slipped over. Looking at it now I would imagine it would have been about 1/2" diameter and about 3-4" long, before it started to unravel. I just don't see the point of it! It would appear that it used to float up and down with the fuel level and partially block the main line once drawn in. The gauze on the reserve was also filthy.
Regards,
Dave
 
You must log in or register to reply here.
Back
Top