lumpy/rough running

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jrt
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Re: lumpy/rough running

Post by jrt »

Right, something else to check tomorrow. Will have a search on here for ways to check it.
David.
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937carrera
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Re: lumpy/rough running

Post by 937carrera »

I have just read through your posts again. Am I right in thinking that all was OK until you put some fuel in ?

Not pulling in 5th indicates a lack of low down torque / power, it could be a bad batch of fuel. Doesn't happen that much these days, but that doesn't mean it never happens. How much fuel did you put in and what was already in the tank ? How much is in the van now ?
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jrt
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Re: lumpy/rough running

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Yes happened just after pulling away from the petrol station 5 mins up the rd. Needle was just before the first mark, always fill it up when it gets near that. Put £20 in and drove about 20 miles on it. Then last Saturday put another £20 in at the station i always use and went about 30 miles. It did seem better but since then i'd replaced the knackered Vacuum advance unit. Currently reading through posts about the second choke hoping to find some help :|
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937carrera
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Re: lumpy/rough running

Post by 937carrera »

It could just be coincidence, but there's at least a decent chance it is contaminated fuel, eg.

https://www.liverpoolecho.co.uk/news/li ... l-13181241

https://www.thesun.co.uk/news/2633750/m ... ith-water/

You know how unreliable t25 fuel gauges are, so let's assume you had 15 litres in, and added 16, drove off 4, leaving 27

Then added another 16 and drove off 7, so you have around 36 litres at the moment, 3/4 of a tank ?

One approach would be to simply drain off all the fuel and put fresh fuel in, but you have a couple of issues: 1. Having storage for that quantity of fuel, 2. actually draining the fuel out of the tank as there isn't an effective drain without at least partly removing the tank. Another alternative would be to simply dilute the contamination by filling up with fresh fuel, but if your tank is 3/4 full there isn't that much to be gained.

Coming back to the second choke you can simply take the top off (don't drop the nuts/ washers in) and manually operate the throttle to make sure that 1. The butterfly is secure and moving with the actuating rod, 2. you might be able to see that the accelerator pump is delivering fuel into the second choke when you open the throttle sharply.

Carbs aren't my strong point and others will certainly have more experience, so keep on reading :)
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

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jrt
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Re: lumpy/rough running

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Cheers, will do. I don't mind trying to methodically rule things out the best i can (with help on here :ok ) I'll give it another hour tomorrow night and take it from there.
David
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R0B
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Re: lumpy/rough running

Post by R0B »

Might be worth trying if you have water contamination.My beetle has a bit of water in the fuel so will give it a try.Don't know how good it is though.https://www.eurocarparts.com/ecp/p/car- ... NQQAvD_BwE" onclick="window.open(this.href);return false;
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jrt
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Re: lumpy/rough running

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Cheers Rob, will bear it in mind. Couldn't see anything when i changed the filter and pumped some into a bottle through the pump but you never know.
David
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itchyfeet
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Re: lumpy/rough running

Post by itchyfeet »

Have you checked/replaced the fuel filler neck if this is perished you can get water in fuel.
filling up may be a coincidence was it very wet that day for example?
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R0B
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Re: lumpy/rough running

Post by R0B »

I have a brand new ignition amplifier should you want to try it fella.
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jrt
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Re: lumpy/rough running

Post by jrt »

itchyfeet wrote:Have you checked/replaced the fuel filler neck if this is perished you can get water in fuel.
filling up may be a coincidence was it very wet that day for example?
No not replaced it, have checked it when cleaning out the wheel arches a while back but will re check tomorrow. As for the weather it was a dry, sunny but freezing day and we'd not had any rain for a week. Just been reading the posts about the secondary choke-there's quite a few!!
David
Last edited by jrt on 05 Mar 2018, 22:37, edited 1 time in total.
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jrt
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Re: lumpy/rough running

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R0B wrote:I have a brand new ignition amplifier should you want to try it fella.
Thanks Rob i may be in touch. I initially thought if that was faulty you'd get starting problems but having had a quick read it can give some symptoms similar to mine ie poor acceleration/lack of power...
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Re: lumpy/rough running

Post by itchyfeet »

When you changed the dizzy vac unit did you check/set ignition timing with vac disconnected?

did you check the vacuum is moving the hall sensor inside the dizzy once fitted?

even if these are not the fault they need doing.
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jrt
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Re: lumpy/rough running

Post by jrt »

itchyfeet wrote:When you changed the dizzy vac unit did you check/set ignition timing with v.
ac disconnected?

did you check the vacuum is moving the hall sensor inside the dizzy once fitted?

even if these are not the fault they need doing.
Yes.. Will check secondary choke tonight and maybe take Rob up on his offer of his ignition amp to rule that out.
David.
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itchyfeet
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Re: lumpy/rough running

Post by itchyfeet »

borrow the dizzy vac pipe and connect to the 2nd choke vac unit so its long enough to suck and look

then open throttle manually fully and suck you should see the 2nd flap open

then pinch the tabs around the plastic interlock with pliers so there is minimal play.

yes take rob up on the offer.
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jrt
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Re: lumpy/rough running

Post by jrt »

itchyfeet wrote:borrow the dizzy vac pipe and connect to the 2nd choke vac unit so its long enough to suck and look

then open throttle manually fully and suck you should see the 2nd flap open

then pinch the tabs around the plastic interlock with pliers so there is minimal play.

yes take rob up on the offer.
:ok
David.
the future is unwritten

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