Lancia Motor Club

Model Technical and Interest => Fulvia => Topic started by: Richard Fridd on 20 July, 2011, 02:51:29 PM



Title: carbs
Post by: Richard Fridd on 20 July, 2011, 02:51:29 PM
hi all,my sedan has developed a hesitation when accelerating gentle.if i depress the gas pedal for swifter progress the car accelerates strongly.i suspect a problem with the idle circuit .i have a new fuel pump/air filter/plugs fitted and have checked/cleaned the screws+jets which are accessible from the top.i have checked the fuel levels in the bowls which are equal.i have balanced the airflows with a meter.i suppose the accelerator pumps under the carbs could be disguising a blocked fuel filter in the tank or other restriction.advice welcome as ever.best regards richard


Title: Re: carbs
Post by: fay66 on 21 July, 2011, 01:12:31 AM
hi all,my sedan has developed a hesitation when accelerating gentle.if i depress the gas pedal for swifter progress the car accelerates strongly.i suspect a problem with the idle circuit .i have a new fuel pump/air filter/plugs fitted and have checked/cleaned the screws+jets which are accessible from the top.i have checked the fuel levels in the bowls which are equal.i have balanced the airflows with a meter.i suppose the accelerator pumps under the carbs could be disguising a blocked fuel filter in the tank or other restriction.advice welcome as ever.best regards richard
Hi Richard, are you getting deposits up to the carb fuel filters that sit on top under the big hexagons? do you have a pressure regulator/fuel filter with the glass bowl, at first I had no end of problems with rubbish from the tank getting up to the carbs, so I fitted a "Filter King" from Demon Tweeks, if I remember correctly it was only about 35 at the time, this cured the problem, but I thought later Fulvia's had a fuel regulator/ fuel filter as standard ???
I bought a new brass filter for inside the tank years from Omicron, but I've never plucked up enough courage to remove the threaded plug from the bottom of the tank, as I have visions of tearing a lump out of the tank being that it's been there so long ::)
Brian
8227 8)


Title: Re: carbs
Post by: HF_Dave on 21 July, 2011, 09:40:44 PM
It's a good idea to drain the tank, I did it with Kevin Mc Bride on the Fulvia. I got under the car with spanner and bucket, kevin stood by but as soon as I undid the nut out came a huge gush of petrol , In seconds the bucket was full, I was there trying to put the bung back in, Kevin was running around looking for  another bucket I was covered in petrol, you coulden't light a match near me for about three days. The moral of the story, never underestimate the amount of fuel in the tank. I reckoned about half a gallon but I was supprised at the amount of fuel and gunge that came out as well.  But a job worth undertaking . Thanks David. ;D


Title: Re: carbs
Post by: fay66 on 22 July, 2011, 02:07:08 AM
It's a good idea to drain the tank, I did it with Kevin Mc Bride on the Fulvia. I got under the car with spanner and bucket, kevin stood by but as soon as I undid the nut out came a huge gush of petrol , In seconds the bucket was full, I was there trying to put the bung back in, Kevin was running around looking for  another bucket I was covered in petrol, you coulden't light a match near me for about three days. The moral of the story, never underestimate the amount of fuel in the tank. I reckoned about half a gallon but I was supprised at the amount of fuel and gunge that came out as well.  But a job worth undertaking . Thanks David. ;D

"Come on Baby Light my Fire" :o
Dave,
Perhaps in hindsight it might be worth syphoning some out first, if you remove the Gauge unit in the tank you can see the level of the fuel remaining.
Did it come undone very easily? I think it must have been removed when "Fay" was restored, as there doesn't seem to be a lot of rubbish in the tank from what I could see when I had the gauge unit out to clean it the other week, it's just that I would like to check the condition of the in tank filter as I can't see whether or not it was replaced at the time.
Just one point, is there a washer or a seal under the filter?
Brian
8227 8)


Title: Re: carbs
Post by: roddy on 22 July, 2011, 06:35:49 PM
Hello Brian

The brass plug in the tank takes the usual 14mm allen socket for the sump and gearbox.   The filter element in the tank does have a seal :-   Neale Shepherd wrote a brief article in V.L. about a couple of years ago following on his problems with fuel supply in his Zagato 'Competizione'.   From a fading memory (!), the seal had gone soft, expanded, and was partially blocking the end of the pick-up pipe in the tank (the filter element surrounds the end of the pipe to prevent residue pick-up).

Regards - Roddy


Title: Re: carbs
Post by: fay66 on 23 July, 2011, 12:12:54 AM
Hello Brian

The brass plug in the tank takes the usual 14mm allen socket for the sump and gearbox.   The filter element in the tank does have a seal :-   Neale Shepherd wrote a brief article in V.L. about a couple of years ago following on his problems with fuel supply in his Zagato 'Competizione'.   From a fading memory (!), the seal had gone soft, expanded, and was partially blocking the end of the pick-up pipe in the tank (the filter element surrounds the end of the pipe to prevent residue pick-up).

Regards - Roddy

Thanks Roddy,
That rang a bell! I seem to remember the article, I'll have to look it up.
do you know if the seals are available or is it a case of make one yourself, can't imagine it would be too complicated.

brian
8227 8)


Title: Re: carbs
Post by: roddy on 23 July, 2011, 04:30:01 PM
Hello Brian

I think the seal is just a round disc to hold the filter element in place (?) - you might need to cut it from a suitable sheet.   I have also a dim memory that Neale had a diagram or photo (?).   I wish my memory was as sharp as a youngsters!!

Regards - Roddy


Title: Re: carbs
Post by: HF_Dave on 23 July, 2011, 10:12:07 PM
Hi Brian, when I went to take out the bung the fuel gauge was at empty, the fuel gauge was accurate before undertaking the job, but I reckon there was about 2 gallons of furl in there, I allways thought there was less than a gallon when the light came on. Thanks, David. :)


Title: Re: carbs
Post by: fay66 on 23 July, 2011, 11:37:46 PM
Roddy & Dave,
Thank you for the information, 2 gall left when the reserve light comes on! that's about a 1/4 of a tank on "Fay" ::)

Brian
8227 8)


Title: Re: carbs
Post by: lancialulu on 24 July, 2011, 05:12:36 PM
Brian

Drive around with your spare can till you run out.

I have some photos of the filter arrangement I can send you after AGM.

It's not that difficult but the spray of petrol os horizontal even on a near empty tank. you can fit a replacement nylon tip filter which is used in glass canister type filters. I did this on my sport.

Tim


Title: Re: carbs
Post by: nistri on 25 July, 2011, 06:35:35 AM
If an eletrci fuel pump is fitted, it is very simple to empty the tank by connecting a temporary fuel line to the pump outflow into a jerry can and to control the fuel supply by switching the pump on/off. Andrea


Title: Re: carbs
Post by: the.cern on 25 July, 2011, 08:16:28 AM
That is the sort of solution that appeals to me Andrea !!  It's simple, cheap and controllable, there's very little in life about which you can say that !!

                      Andy


Title: Re: carbs
Post by: fay66 on 25 July, 2011, 10:15:33 AM
If an eletrci fuel pump is fitted, it is very simple to empty the tank by connecting a temporary fuel line to the pump outflow into a jerry can and to control the fuel supply by switching the pump on/off. Andrea
Andrea,
Thanks for that, I didn't think of it even though I've got an electric pump fitted,  :-[

Brian
8227 8)


Title: Re: carbs
Post by: neil-yaj396 on 26 July, 2011, 04:11:12 PM
I'm glad that health & Safety has prevailed (if you have an electric pump)! My wife's old Beetle once drenched me in petrol prior to some work on the engine, with that 'high up at the front' tank setting up a perfect syphon. It is a very unpleasant experience.


Title: Re: carbs
Post by: Richard Fridd on 03 August, 2011, 06:27:56 PM
hi all,my sedan has developed a hesitation when accelerating gentle.if i depress the gas pedal for swifter progress the car accelerates strongly.i suspect a problem with the idle circuit .i have a new fuel pump/air filter/plugs fitted and have checked/cleaned the screws+jets which are accessible from the top.i have checked the fuel levels in the bowls which are equal.i have balanced the airflows with a meter.i suppose the accelerator pumps under the carbs could be disguising a blocked fuel filter in the tank or other restriction.advice welcome as ever.best regards richard
carbs stripped and cleaned and refitted.fuel supply good.in addition to a slight hesitation particularly when not fully warmed there is a slight 'backfiring' on the over run which i have had with other fulvias but only when lifting off from high revs.will change condenser etc with some spares unless somebody can advise otherwise.i still suspect carbs though.acceleration remains strong.i did try a richer idle mixture but not successful.advice welcome !best regards richard


Title: Re: carbs
Post by: lancialulu on 03 August, 2011, 08:42:45 PM
Richard

Its not backfiring but popping of unburnt fuel! most fulvias seem to do this and I have been told that a leaky exhaust that lets air in (?) increases this. I have to say my 1.3 Coupe now in safe hands up in Carlise always popped but had a very sound exhaust system. to eliminate fuel pressure issues you should buy a cheap fuel pressure meter c 10 and fit in line with carb delivery.

Tim


Title: Re: carbs
Post by: thecolonel on 04 August, 2011, 10:17:49 AM
Be careful purchasing a fuel pressure gauge.
A lot of them are for testing purposes only
and not designed to be left "in circuit".


Title: Re: carbs
Post by: lancialulu on 04 August, 2011, 04:05:19 PM
Re FPG - Totally agree only for testing. How could you see it as a permanent installation anyway unless plumbed to the dash board where you dont really want a fuel pipe!!

Tim


Title: Re: carbs
Post by: Richard Fridd on 06 August, 2011, 03:59:16 PM
hi all,my sedan has developed a hesitation when accelerating gentle.if i depress the gas pedal for swifter progress the car accelerates strongly.i suspect a problem with the idle circuit .i have a new fuel pump/air filter/plugs fitted and have checked/cleaned the screws+jets which are accessible from the top.i have checked the fuel levels in the bowls which are equal.i have balanced the airflows with a meter.i suppose the accelerator pumps under the carbs could be disguising a blocked fuel filter in the tank or other restriction.advice welcome as ever.best regards richard
carbs stripped and cleaned and refitted.fuel supply good.in addition to a slight hesitation particularly when not fully warmed there is a slight 'backfiring' on the over run which i have had with other fulvias but only when lifting off from high revs.will change condenser etc with some spares unless somebody can advise otherwise.i still suspect carbs though.acceleration remains strong.i did try a richer idle mixture but not successful.advice welcome !best regards richard
have now replaced condenser/dist. cap/adjusted points.still suspect carbs-additional symptom is when coming off the gas  the idle speed is 1400 rpm before settling to 800 rpm after 20 secs.does any one know if this is a symptom of an air leak and if so where could such a leak be?best regards richard


Title: Re: carbs
Post by: lancialulu on 06 August, 2011, 05:12:44 PM
sounds like it could be a manifold leak. Have you ever taken these apart? I found the the best way to ensure these dont leak is (even using new gaskets) to use a copper loaded silicone sealant (just a smear as you dont want the venturi having a ridge of sealant). It could also be worn spindles causing the butterflys not to close properly and then the find their stop position. A second throttle spring may assist.

Tim


Title: Re: carbs
Post by: Richard Fridd on 19 August, 2011, 12:20:36 PM
part of the problem is slightly clearer.the idle speed is altering depending on whether the clutch is depressed when the car is stationary[ie clutch dragging when in neutral]there is a further intermittent problem re clutch-occasionally if i select 1st gear for example i cannot get back into neutral unless i turn the engine off first.this has only happened so far with a cold engine/box.will the cluch fail soon can anyone tell me?best regards richard


Title: Re: carbs
Post by: lancialulu on 19 August, 2011, 01:29:26 PM
Could also be gearbox oil issue??

Tim


Title: Re: carbs
Post by: Richard Fridd on 19 August, 2011, 05:22:16 PM
oil level correct.richard


Title: Re: carbs
Post by: rogerelias on 19 August, 2011, 09:41:19 PM
Check for thrust washer movement, ie, crank moving back and forth.when crank pulled and pushed,


Title: Re: carbs
Post by: fay66 on 19 August, 2011, 10:50:57 PM
Check for thrust washer movement, ie, crank moving back and forth.when crank pulled and pushed,
With the engine running get someone to operate the clutch while you watch the crankshaft pully for any movement forwards and backwards, Vauxhall 3 bearing cranks with thrust washers either side of the centre bearing only were very prone to this.

Brian
8227 8)


Title: Re: carbs
Post by: Richard Fridd on 10 September, 2011, 08:27:05 AM
no visible movement when operating clutch with engine running,so with engine not running i have applied pressure with a lever to the front crankshaft pulley[pushing the pulley rearwards]and with an assistant depressing the clutch pedal[pushing against my lever pressure]detected very slight movement- maybe 0.25 mm and difficult to measure.is this acceptable?manual says crankshaft end play is 0.052-0.255mm.best regards richard