AlexXtreme
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| posted on 22/3/14 at 05:10 PM |
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fuel pump running dry
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
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40inches
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| posted on 22/3/14 at 05:53 PM |
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Has the fuel tank got a vent? Sounds like ,possibly, vacuum in the tank.
Try driving with the filler cap loosened.
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melly-g
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| posted on 22/3/14 at 06:19 PM |
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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.
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gremlin1234
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| posted on 22/3/14 at 08:24 PM |
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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.
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rusty nuts
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| posted on 22/3/14 at 08:46 PM |
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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 .
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britishtrident
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| posted on 22/3/14 at 11:31 PM |
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quote:
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.
I have seen the same thing floating debris in thebtan.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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AlexXtreme
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| posted on 23/3/14 at 07:04 PM |
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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
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AlexXtreme
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| posted on 31/3/14 at 01:24 PM |
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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.
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AlexXtreme
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| posted on 31/3/14 at 09:24 PM |
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Anyone... any further suggestions welcome
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BaileyPerformance
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| posted on 31/3/14 at 09:33 PM |
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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 :-)
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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AlexXtreme
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| posted on 31/3/14 at 09:50 PM |
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Thanks that is something to check, how long do they last in general? Not the bosch ones that I screen :-)
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BaileyPerformance
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| posted on 31/3/14 at 10:03 PM |
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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.
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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AlexXtreme
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| posted on 1/4/14 at 09:18 PM |
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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
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BaileyPerformance
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| posted on 1/4/14 at 10:53 PM |
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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
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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BaileyPerformance
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| posted on 1/4/14 at 10:53 PM |
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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
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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jeffw
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| posted on 2/4/14 at 07:56 AM |
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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.
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40inches
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| posted on 2/4/14 at 08:33 AM |
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quote:
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.
My thinking exactly. Before going to the expense of replacing pumps, rectify the above. At the very least run it until the symptoms recur, hop out of
the car and release the filler cap, if there is a rush of air into the tank you have found the problem.
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AlexXtreme
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| posted on 2/4/14 at 09:12 AM |
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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
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40inches
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| posted on 2/4/14 at 09:55 AM |
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quote:
Originally posted by AlexXtreme
immediately after a re-fill they disappeared and I was running at high speeds.
Cheers
Alex
Refilling means taking off the filler cap, and possibly equalising fuel tank pressure.
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AlexXtreme
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| posted on 2/4/14 at 10:11 AM |
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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
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Dingz
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| posted on 2/4/14 at 10:49 AM |
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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.
Phoned the local ramblers club today, but the bloke who answered just
went on and on.
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AlexXtreme
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| posted on 2/4/14 at 11:00 AM |
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Good ideas on the hoses / rubbish in the tank. I will replace them and look at or replace the filter.
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DW100
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| posted on 2/4/14 at 11:20 AM |
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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]
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gremlin1234
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| posted on 2/4/14 at 12:00 PM |
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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.
the pump is cooled by the fuel, so could be pump overheating with the low flow.
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AlexXtreme
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| posted on 2/4/14 at 12:05 PM |
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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!).
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