Do fuel pumps fail suddenly?

[ScienceBoy]

Lol
I've got the screw in filter too. But I'm going to put a disposal one in front too. Belt and braces.
You talk elsewhere about having to work a fix for the 8mm line. Did you do away with the plastic line? Did you get adapters from somewhere?

[bigherb]

Lol
I've got the screw in filter too. But I'm going to put a disposal one in front too. Belt and braces.
You talk elsewhere about having to work a fix for the 8mm line. Did you do away with the plastic line? Did you get adapters from somewhere?

You can do it two ways fit the 6mm outlet union.
http://www.ebay.co.uk/itm/Fuel-Pump-Bra ... 4165bf5a30" onclick="window.open(this.href);return false;

Or an adapter hose
http://www.brickwerks.co.uk/index.php/t ... -line.html" onclick="window.open(this.href);return false;

[CovKid]

Yes, dispensed with plastic line and ran all the way to carb with 8mm. Less chance of leaks (or at least only two potential places instead of four), beyond the pump. Fuel is now under pressure ofcourse - unlike the mech pump which (excuse the pun) - sucks.

Theres more than one way of doing it. That just seemed the simplest. Just make sure you use cable ties where prudent to ensure line doesn't foul anything and goes through a gromet where it has to pass through any tinware etc.

[ScienceBoy]

So mine is in and working, but after leaving for a day it just take a lot of cranking before the engine fires up. Leaving for just an hour and he starts up immediately.

Now it could be that my service is overdue, but I'm thinking the fuel must be draining back to the tank. Even with that I was expecting from posts above that the fuel would there as good as immediately. I've really clamped the hose connections tight (I believe).

What's others experience?

Ps. I had some imperial hose bit bigger than 6mm but not 8mm.

[CovKid]

Depends how you wired it. If its via alternator, pump will not start until ignition light goes out. It can drain back sometimes, this is why I fitted a primer switch to actuate the pump if line is dry.

Otherwise it might be flooding (sniff around carb - you'll soon know). I had to fit a carb kit once the electric pump was fitted as the float chamber was overfilling (duff valve in carb). Theres more pressure remember and if float valve doesn't shut off fuel properly you can over-fuel and it won't start. Got a kit on ebay for about £40. Cured it. I hadn't actually sussed the cause - was more a hunch that proved right. Ran a whole lot better too.

[ScienceBoy]

Thanks. I have mine run from the starter on the normally closed feed, and then from the ignition novel the alternator is going, so it should be pumping from the off. I'll keep digging around.

[CovKid]

Watch for flooding though. Will smell strongly of petrol near carb if it is. The float valve may have been quite comfortable with the meagre output of an old mech fuel pump but now its being pushed through more forcefully and its only the float valve that will stop it from keep on going. Really you need to ascertain that the engine is getting fuel and if it is, is it too much.

Must admit I was a bit peeved at having to regasket the carb but it did sort it in my case. Does sound like it if you leave it and it then starts OK, but check around first,

[ScienceBoy]

Went out the run through all this and the battery was flat as a pancake. Hmmmmm. Noticed the radio was lit up before, perhaps I fused something when I connected in the pump (I know I know you should disconnect the battery...)

[ScienceBoy]

So anyhoo, I pulled the old mechanical fuel pump off tonight and had a play. It pumps just fine [CONFOUNDED FACE]
I measured the rod and it's about 0.5mm short of 10mm if that. The pointy end is certainly flatter than picture in JK.

Perhaps I jumped a bit too soon?
Perhaps getting a new rod will give me a mechanical spare if/when the electric fails?

[ScienceBoy]

Measured the old rod with callipers at 9.55cm. Is that really enough to stop the pump working? Might there be something else going on?

[kevtherev]

It will significantly pump less.
Especially if the lobe is worn

[ScienceBoy]

And if the lobe (engine or pump?) is also worn then a new rod would not solve all woes?

[kevtherev]

And if the lobe (engine or pump?) is also worn then a new rod would not solve all woes?

I think it's worth getting as you say for a spare.
Delivery of fuel should be measured in bar, 0.3 being optimal, less than 0.2 and you're going to have trouble.