Hi All,

My fuel pump is running dry however I am almost full of fuel and as far as I can see the fuel filter looks clear. It lasts for around 20 seconds and the car almost comes to a halt then gets going again! So far it has only happened twice. I had a look at it today and could see nothing wrong, went for a drive and it did not replicate the problem. I am worried that if this happens again I could be spinning off. Could the pump be on the way out? How long do they last?
The fuel pump looks like this,

http://www.carbuildersolutions.com/uk/fuel-injection-pump-3-bar

I could not see a manufacture on the pump, and the filter is a plastic job..

Any ideas?

Cheers
Alex

Has the fuel tank got a vent? Sounds like ,possibly, vacuum in the tank.
Try driving with the filler cap loosened.

Is the outlet from the tank clear?
I had a similar problem with mine, it was silicon sheet
I used as a seal on the sender falling to bits and getting
sucked into the outlet pipe.

how is the pump mounted,
usually the inlet has to be at the bottom, with 'flood fill' from the tank

but as others have said, vacuum in the tank is the probable cause. and it will be worse when the tank is full.

Are you using a swirl pot. With a primer pump? I had trouble with my car , it was caused by the FAcet pump pre filter being clogged. I got over it by using aa in line fuel filter before the lift pump .

quote:

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Originally posted by melly-g
Is the outlet from the tank clear?
I had a similar problem with mine, it was silicon sheet
I used as a seal on the sender falling to bits and getting
sucked into the outlet pipe.

---

Hi All, thanks for the comments...

The car is quite old (well the fuel tank part is - over 14years), so unless the fuel is contaminated I dont think anything could get into the fuel line. The tank outlet pipe is black rubber but I can see the clear fuel in the plastic filter.

I can not see a vent on the fuel tank however the top is not at all visible. I will try loosening off the filler and see if it makes any difference - good idea. Just a thought, would the vent be built in to the filler cap? It looks like this

Locking Aluminium Fuel Filler Cap Kit Car Motorsport Race Complete Kit RD2440

Just a thought, It happened after going over some pretty nasty sleeping policeman, I guess that could have slurped the fuel around enough to restrict any venting in the filler cap as the fuel was pretty at the time.

The fuel pump is mounted on the bulkhead below the tank with a direct feed from the tank of only around 450mm of pipe. I don't have a swirl pot, although have been think of one lately as I can not go below about 40% of the tank capacity without hearing the fuel pump run dry now and again on sharp corners. Ideally I would like a small capacity swirl pot... any suggestion? I would keep the return back in to the tank I think ... but again open to ideas?

Cheers
Alex

Hi All,

Went for a "spirited drive" on Sunday morning - nice an early before the crowds on the road built up and the car was great - no sign of fuel starvation or the pump running dry.

Had a nice breakfast at a bikers caf, as you do, and then whilst doodling back through town the pump started getting nosier and then the same problem as before occurred, with the pump sounding like it running dry and the engine stalling due to lack of fuel. I did not come to a stop but almost did! Pulled in and restarted OK. After a mile or so and when I got on to more open roads it all seemed ok.

I am a bit baffled to what could cause this. It is not
- starvation due to lack of fuel. I re-fuelled and could only get 10 litres in.
- air lock, it only happened when running slowly and when the tank was full it made no difference.
- could it be a blockage? Surely it would be worse at higher speeds??

Questions I have:
Is the pump working harder at lower revs when there is less fuel flowing and what I have is the signs of the pump on the way out?
What are the signed of the fuel pressure regulator malfunction?

Any other ideas? I am worried next time I go out it will die on me, so it staying in the garage until it is sorted.

Anyone... any further suggestions welcome

Does the pump feel cold to touch?

If hot it's fuel starvation, if cold it's not.

My money would be on the pump, looks like a crap Chinese one to me. Go get a genuine Bosch :-)

Thanks that is something to check, how long do they last in general? Not the bosch ones that I screen :-)

I have an Autograss customer who fitted a cheap pump, a couple if races, car started to run rough, we put on the dyno and it was running lean - checked fuel pressure and it was unstable, the customer gave me another new pump, that lasted another few races and stopped completely.

In the end I fitted a the pump from my Cosworth, the car is still going great, this was 2 years ago.

Always buy a genuine Bosch pump, there is a reason why ford and vauxhall use Bosch.

The japs use Denso, also good pumps.

Cheers all,

Ill check the pump and see it is running hot or cold.
Other than Bosch (they are expensive!), what other makes are OK? I need to make sure the hose dia fit before buying :-)
What about Walbro or APS? There is 2 year warranty on the APS pump.
Cheers~Alex

APS, in my opinion, are just another cheap brand, probably poor quality.

The way to save money is to buy a good pump - buy good buy once.

Bosch pumps are not that expensive, when you consider they will last the life of the car you are fitting it too, 100kmiles minimum.

Only use Bosch, Denso, Walbro

APS, in my opinion, are just another cheap brand, probably poor quality.

The way to save money is to buy a good pump - buy good buy once.

Bosch pumps are not that expensive, when you consider they will last the life of the car you are fitting it too, 100kmiles minimum.

Only use Bosch, Denso, Walbro

So no vent and no swirl pot (either in the tank or external).....I think you can safely say one or other of these will be the issue.

quote:

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Originally posted by jeffw
So no vent and no swirl pot (either in the tank or external).....I think you can safely say one or other of these will be the issue.

---

Hi Guys, the filler cap contains a vent from what I have read. I will try and release the filler when the symptoms appear as you say however I had the symptoms with a 60% full fuel tank running at low speeds round town and when immediately after a re-fill they disappeared and I was running at high speeds.

I agree a swirl pot would be useful! Any suggestions for a low capacity pot..? I don't have much room in the area.

BarleyPerfomance - thanks for the suggestions makes to use.

Cheers
Alex

quote:

---

Originally posted by AlexXtreme
immediately after a re-fill they disappeared and I was running at high speeds.
Cheers
Alex

---

Good point...

However I had only left from a cafe after full English Breakfast and during this time the car was stationary for 45mins... prior to the b'fast I had just driven 1 hour cross county with some spirited driving (trying to keep up with a Ducati 1098 ) with no issues.

Around November last year I had the car rolling road tuned for a good hour and it pulled a good 148hp at 7000rpm which I was happy with from a 1.6 Zetec. I am sure if the tank was not vented it would have picked this up.

Cheers
Alex

Could still be rubbish in the tank floating about and blocking the outlet pipe or if the rubber hose is the original it will be in a poor state by now and could be causing problems.

Good ideas on the hoses / rubbish in the tank. I will replace them and look at or replace the filter.

If it were a customer coming in to me I'd be road testing it with an amps clamp on the fuel pump supply and a fuel pressure sensor both connected via Picoscope to a laptop.

The amps clamp provides enough detail to be able to see each individual pump motor segment drawing current as it rotates.
You can see a duff motor easily. You can also see speed of rotation and average current draw will show how hard it is working.


Description


Description

The top one is the waveform from a golf that had an intermittent starting issue, the surprise was it ran most of the time. The bottom waveform is a new pump.

[Edited on 2/4/14 by DW100]

[Edited on 2/4/14 by DW100]

quote:

---

Originally posted by AlexXtreme
Questions I have:
Is the pump working harder at lower revs when there is less fuel flowing and what I have is the signs of the pump on the way out?
What are the signed of the fuel pressure regulator malfunction?

Any other ideas? I am worried next time I go out it will die on me, so it staying in the garage until it is sorted.

---

gremlin1234, thanks for the idea. So at low speeds, there is low fuel flow and so less cooling? Does this suggest the pump is on the way out....?? it makes starts to a racket before and when the car starts to missfire due to lack of fuel (which sounds like lack of fuel but worse!).

If you are running a fuel rail with a return, the speed of the car makes very little difference quantity of fuel flowing. The amount of fuel used will affect the volume in the return line though.

Noisy pumps can be a faulty pump or running dry.

Hi Guys,
thanks for your help on this and I have decided to bit the bullet and replace the system with something that works, rather than that was fitted by the factory and did not :-(.

Anyway I have decided to go with this swirl pot as it can fit in the limited space I have

http://www.fuelpumpsonline.co.uk/fse-fuel-swirl-pump-pot-ccp001-241-p.asp

together with an inline fuel pump either the Bosch or similar

What find of priming fuel pump do I need... I number of companies have suggested one of these but do I need to go this far for a priming pump?

Std facet pump
http://www.fuelpumpsonline.co.uk/facet-cylindrical-pumps-12v-1821-c.asp

would one of these
Facet posi pump
http://www.fuelpumpsonline.co.uk/facet-posi-flow-pumps-1819-c.asp

or these work

red tops cylinder pump
http://www.fuelpumpsonline.co.uk/facet-solid-state-pumps-12v-1820-c.asp

The pump will be mounted under the tank so will not need to be primed. Most of the pumps will push 32 gallons / hour and as it is only filling the swirl pot, why should I go for the higher spec pump...
I guess some are quieter / more reliable etc, but this is not for a day-to-day used car and will only get occasional track use :-)

Cheers
Alex

Do the simple things first. Replace the filter and give the tank a flush out with some white spirit. If it still does it check the wiring, pump etc.

Chris (Toltec on here) had a similar issue, the filter looked fine, but when we replaced it his fuel starve issue went away

Hi,
The std xtreme fuel tank has a vent point, visible with drivers side rear wheel off, top right hand corner looking in from there, I would expect to see a pipe from this via a breather valve.

Cheers
Tony.R

Hi ashg,
initially I thought it was the filter however it seems to get worse with time which I am assumed was the pump getting hot and starting to fail. Talking to a manufacture of pumps, in-line pumps can only run dry for max 30 seconds before serious is damage is done to them due the very high rpm and damage can start much earlier.
I have brought a new filter and will give it a try however long term I think I will need to change the arrangement as I can not run below 40% fuel without hearing the pump running dry round corners :-(.

Will definitely change the filter to see if it saves me buying another in-line pump though

One other thought was would the swirl pot I propose work with just a gravity feed.

sssline, I can see a return running up from the return piping from the near side over the tank. I did not know which side the vent fitting was though and I will have a good look over the weekend! Do you know what size the std push pipe fitting is on the xtreme tank? As far as I can tell it is 12mm. I am having trouble in getting the rest of any set up in 12mm as the std seems 10mm, i guess a reducer would solve this problem. Are those pics of your car I can see that you have posted?? fantastic looking dash!

Cheers
Alex

Hi Alex,
Top pipes fittings (return) are std 8mm, I think, fuel out on mine is 19mm so I adapted down...

Pictures of my build are on Flickr, there are some of the fuel tank etc in here. https://www.flickr.com/photos/sssline/sets/72157631181387380/

Cheers
Tony.R

Ps I get about 4 gallons of use out of the tank before the pump starts to get starved, did hope a large fuel filter would act as a bit of a reserve on cornering but the flow rate is pretty quick, I am aware of a supercharged XT locally that added a extra sump to the bottom of his tank to overcome surge, tank out for that tho...

The fuel filter should be after the pump, not before, you do not need a filter before the pump - it can also restrict the flow to the pump.
The pump must be below the tank, most EFI pumps are poor at sucking fuel, so a good head of fuel is required.

A genuine Busch pump (from Escort RS turbo or sierra Cosworth) mounted below the tank (no pre-filter) with 12mm feed and 8mm outlet will work fine.

Hi All,

During a quiet period I managed to get back to sorting out the fuel system (after nearly passing out due to too petrol vapour under the car!).

Anyway with a good face mask on replaced the fuel pump and filter under the tank (I did not want to do the job again so replaced both at the same time). This time I used a decent Bosch fuel pump with a nice big filter. The old filter out it was very clean with no sign of any muck.

Anyway I went for a drive again this weekend and the same symptoms have returned . The tank was 1/2 full...

Some other thoughts of the cause. When the car is cold, the pump sounds fine and I can hardly hear it (so this rules out the blocked tank etc) however in this situation that injection system is taking plenty of additional fuel. When the car is warmed up and is running at low speed, even after stopping for a short time, is when the symptoms return.

Could it be the pressure regulator that is faulty and not letting enough fuel through to keep the pump running efficiently and it is stalling which is making the noise? The regulator looks like a Weber type. Do they go wrong and if so how can you test them?

I do not want to spend even more time and money chasing the problem without knowing it has a good chance of fixing my car!

Thanks
Alex