Fuel Starvation

[Paul Greenway]

Having just received my V5C and fitted my plates 'FAX 505K' I took my 1600 Sport for it's first UK run (29km) yesterday. Starting issues have been covered before on this forum and like many other Fulvias it started after 5 or 6 attempts with a mixture of revs and choke. Once idling on the drive I took the choke off and set off. For the first few km it was fine but I then started to notice that on inclines it was losing power and I had to keep dropping down a cog.
I then decided to give it a blast on the motorway and initially all was well until again on an incline it started to lose power, even by dropping down the box it was no good so I pulled onto the hard shoulder. The engine did not cut out and after a few seconds I set off and it was fine again for a period then intermittently lost power on and off until I made it home.
It started first time this morning and idled no problem for about 10 mins before I put it away.
I had put 20L of Shell V-power petrol plus 25ml of fuel additive into it before I commenced yesterdays drive, this had brimmed the tank so there was probably half a tank of unknown fuel already in it. Having said that on my test drive in Germany last November and on my journey (2 miles) to the MOT station in December apart from the starting it drove ok but idled quickly.
I have purchased oil, plugs, filters, Solex 42DDHF carb servicing kit as it's going in for a service/tune up in the next couple of weeks plus the non standard breather and vacumn pipes are being replaced at the same time so hopefully the issues will disappear.

Has anyone any pointers as to what else could be the issue, all advice/comments appreciated. Thanks.

Paul

[Richard Fridd]

Perhaps the choke is stuck on, due to the cable/lever not returnining fully?

[GlynW]

If there is a fuel filter in-line, I would check it.  If not and the problem persists it would be worth putting one in, in case particulates in the tank or fuel lines are reaching the carbs.  I have a Malpassi Filter King with a glass bowl fitted so you can see any sediment.

[Paul Greenway]

If there is a fuel filter in-line, I would check it.  If not and the problem persists it would be worth putting one in, in case particulates in the tank or fuel lines are reaching the carbs.  I have a Malpassi Filter King with a glass bowl fitted so you can see any sediment.

Perhaps the choke is stuck on, due to the cable/lever not returnining fully?

Glyn, yes there is a fuel filter in-line, I will check it out.

Richard, the choke returns ok and the warning light goes out  so I don't think it's a choke issue.

Thanks guys.
Paul.

[fay66]

If there is a fuel filter in-line, I would check it.  If not and the problem persists it would be worth putting one in, in case particulates in the tank or fuel lines are reaching the carbs.  I have a Malpassi Filter King with a glass bowl fitted so you can see any sediment.

I'm with Glyn on this one and the fitting of a Filter King was more than worthwhile on my 2c.

Brian
8227

[roddy]

Hello Paul

Almost classic symptoms of the Fulvia fuel pump gradually failing, which can happen.  Particularly with modern fuels, the rubber diaphragm of the fuel pump hardens and fails to deliver an adequate amount of fuel at higher revs or when demanded.  Although new diaphragms are listed, it might be worthwhile just fitting a new pump - they are remanufactured and not desperately expensive.  One of the benefits of having an electric priming pump for starting is that had you switched it on, and performance was reinstated, the answer to your problem is there.  (If fitting a new pump, do not over-tighten the fixing nuts and the face flange can distort.)(Consider also getting a new diaphragm, fitting it, and carrying the pump as a spare - your friendly AA man won't have one in his van.......)

If you are satisfied that the fuel pump is in the first flush of youth, then another possible source of fuel starvation, is the short flexible pipe from the tank to the metal pipe end on the floorpan, imploding.  If it is a replacement item for the Cavis piping, it may be rubber and have gone soft, or fuel has caused the walls to breakdown.  Squeezing it with your fingers should show if it is soft - it should not be.  Also check that there are no splits anywhere that could suck in air, although you would tend to smell fuel when the car was stationary.  The posts so far are sound advice if there is a risk of sediment etc. in the fuel tank.

Good luck - Roddy

 

[RobD]

I suspect the problem is more fundamental than the choke sticking on but it's worth noting that just because the warning light goes out does not necessarily mean the choke has fully disengaged. It's dead easy to check a] release the choke b] stick your head under the bonnet and check the choke cable is slack and then see if you can push the choke mechanism off a little bit further with your finger.
On my car attending to this made quite a big improvement to the way it ran.

[chriswgawne]

My first port of call would be the fuel pump (checking flow and pressure) particularly looking at the one way  valves inside the pump. Alternatively fit an electric pump inline and see what effect that has.
Also have a look at the carb jets. On my replica C type with triple Webers, I filled it up with high octane Tamoil fuel last April, drove it around and then left it over the very hot summer in Italy. Tried to start it in November and it ran very roughly. All the jets were gummy and on 2 carbs the float chamber valve 'slug' was stuck closed with gummy deposits.
Chris

[nistri]

After checking for problems with the fuel supply/fuel pump, if the problem manifests itself particularly on a slope, it is likely that there is a problem with one (or both) needle valve and the correct movement of the carb float(s). Good luck, Andrea

[Paul Greenway]

Thanks gents for all your advice.

Not being of the mechanical orientation, I will get my friendly mechanic to assist me in checking out all these points and hopefully we shall suss out the fault by process of elimination.

Where's the best source for Fulvia fuel pumps? Do all Fulvias of varying engine size use the same pumps? Can someone please advise, thanks.

[roddy]

Hello Paul

Fuel pumps for a Fulvia are all the same, irrespective of model. Omicron should be able to supply one off the shelf.  Obviously Italy is another source, and they appear on eBay occasionally.  This website :- http://www.ricambirossocorsa.it/en/160-carburetors-lancia-fulvia-by-ricambirossocorsa?&p=2   in addition to listing a complete pump, also list an overhaul kit which appears to comprise diaphragm and flow valves, etc.

One other point that I did not cover in my earlier post, which can occasionally happen is if there is a lot of gunge in the fuel tank, be it sediment or water or flakes of rust.  The pick-up pipe in the tank is surrounded by a mesh filter which is located on the inside of the large brass drain plug in the centre bottom of the tank.  Hex key is the same size as the sump and gearbox drain plugs.  The mesh could become partially blocked and restrict the full flow of petrol.  This is really a 'last gasp' area to consider if all else has failed to sort out the problem, which I still think is fuel starvation.  The mechanical pump only delivers fuel at about 2 - 3 psi. so that is not a great pressure to overcome any restriction in the supply side.

Regards - Roddy 

[Paul Greenway]

Thanks Roddy,

Already ordered new fuel pump and Malpassi Filter King to go with other service items previously mentioned. We'll get to the bottom of the problem one way or another.

Cheers,

Paul

[neil-yaj396]

The symptoms are very similar to the problems I had with my Beta which I bought after a several year lay up. That was dirt in the carb. It was eventually cured by dismantling the carb and blowing everything through with an airline.

Covered at length in the carb section of the Betaboyz Forum.

[RobD]

Paul,
I'm mindful that you said you haven't got a lot of experience with mechanics
Cleaning and/or rebuilding carbs is a labour intensive process and can be expensive if handed over to a mechanic. Carbs can look complex and daunting if you've never stripped them before but are in fact relatively straightforward and enjoyable to work on. If you want to eliminate the carbs as a source of the problem ideally they should be removed, stripped and the bodies ultrasonically cleaned to ensure all the various airways and passages are cleared.

[Paul Greenway]

Just had car returned after 5 weeks being 'refettled. It's now running like a dream, took it for a 40 mile spin over the tops, fast roads, town & motorway where it behaved impeccably.
It's had the following completed to sort out the fuel starvation issue-
1) New Fuel Pump.
2) New Fuel Filter.
3) Carbs fully serviced and re-set up.
4) Fuel tank removed, sediment, rust & other crap removed (quite an eye opener), tank power washed, painted, re sealed and fitted.
5) Rolling Road/Dyno tune set up- now pumps out 111bhp at engine & 89bhp at wheels.
6) New NGK Plugs, Mahle Oil Filter, Mobil 1 synthetic oil, Framm OEM air filter.
7) New V belt.
Timing chain & other ancillaries checked.

Additionally it has had new front shockers fitted, o/s front CV joint, F& R seat belts fitted and o/s OEM door mirror (no real use but looks good).

It's now bellissimo! '