Discussion in 'Mech Tech' started by dazzaxjr, Aug 24, 2011.
Well, redid experiment 1 with the petrol mouthwash.
I can suck water from the 1st bucket, through the pump with no problem. As soon as I put the hose into the empty bucket the pump doesn't pump.
Even tried reversing polarity of pump electrics, but no joy.
Good news is I should be getting a hire car tomorrow so I can at least start scouting round for car spares places.
I've tried the pump both ways. Doesn't work. Also tried wiring up both ways and doesn't work.
The little thing is a filter. I've tried with and without this and still doesn't work.
I know what you mean though. I can't believe I've got 3 faulty fuel pumps. How can I be that unlucky? There must be something I'm missing here but for the life if me I don't know what.
Long shot but..... Have you tried wacking the pump with a lump of wood? I am
Guessing they will be similar to the old SU pumps? I had a second hand SU pump fot my other halfs wolseley. After cleaning everything in site especially the contacts , connected to battery not a sausage. After a bit of head scratching , i wacked the pump body with wooden block, waited and lo it kicked into life, there was a delay before it started.
You might have some daft air lock ? But electric pumps are all different though? But what habe you to lose?
I did try hitting it with a spanner, but didn't seem to help.
Was it magic wood?
This afternoon I'm stripping the whole lot out again to test the empi pump. Hopefully to prove once and for all if I have 2 faulty pumps or some other problem.
according to the bently manual the delivery for stock twin carbs should be 400 cc per minute which to my understanding of is max the stock twin carbs need to make the engine do 3800 rpm (this is a bit of a disjointed explanation as it refers to a mech pump) so you can test your empi pump into a measuring jug if you get 400cc (400ml) in a minute, which isnt alot, then yoiur engine should be capable of 3800 rpm which has got to be more than 35mph i hope this makes sense and is correct.
I dont know what t'internet your using out there but if you dont have workshop manual this is worth a download its 130mb: http://www.filesonic.com/file/1497324361/T2%20Manual.rar
and here: http://www.ratwell.com/ is a great resource it also has an index on it to make ^ that manual easier to navigate (its 29 on sites list)
One last little thing, On the new electric pump there arnt any transport screw or blanking caps anywhere are there?
Thanks major. If the pump works I'll measure the flow. My van has a type 4 2l engine with twin dellorto carbs.
I assume these will accept slightly higher flow rate. Will measure using the very scientific "twin bucket" method as per experiment 1 above
P. S. No screws or adjustment of any kind on the pumps.
Pulled the empi pump back out the van and setup the experiment.
Bottle at the top full of water, through pump to empty bucket. Guess what! It pumps! Pulling though about 1l of water in about 1min, give or take a few seconds.
Hmmm. Whilst pumping the pump sounded irregular. Not a smooth rhythm. Also it seemed to have trouble getting started and once I had to suck water into the pump to get it started.
So what have we learned? Seems that in experiment 1 the pump is faulty. In experiment 2 it's maybe ok sometimes once it gets started.
So now going to take jokers advice an put it all back one last time as follows:
Tank > filter > pump > carbs
Taking out second filter and regulator and also will make sure that pump is installed directly below tank to get some assist from gravity.
In meantime I'll also get another pump shipped tomorrow just in case.
Looks like your having a fab holiday ... ;D Tis boring sitting on a beach... 8)
don't get water mixed with petrol. it'll cause issues. i'd wait for next pump and fit that
Well put it all back again as follows:
New tube from tank, 5.5mm line:
Then connected filter:
From there connected to pump using 8mm line:
From there ran new 8mm line through firewall, and power through different hole:
Inside engine bay ran power to coil with "double" spade connectors:
Also ran fuel line along bulkhead across to carb:
Took a deep breath and added many many cable ties and fired up. Ran and idled well, but found on a test drive that still struggles and stalls.
Restarts ok but will only run slow up to 30-40 ish.
So despite pumping 1l per minute could this pump still be faulty?
Dunno, ordering replacement for other faulty pulp tomorrow and will see what happens.
Unless anyone has any suggestions on what else could be causing the problem?
You sure it's fuel starvation causing the problem? If pump is pumping and runs on idle it seems fuel might not be the issue. If it's ok up to 30, is ignition advancing on higher revs? (Sorry but don't actually have one of these things yet, just drawing on previous experience of other engines) There could be all manner of things. HT breakdown (had same problem myself and only found it in the dark because I saw the sparks leaking out of the cable. New cables from coil sorted out same problem you seem to be having)
how are you splitting the fuel line to get to both carbs?
Looking at other threads it could be coil, ht leads. Only going with fuel starvation at the moment because of all the fuel pump problems I've had.
At the moment I'm not 100% confident in the current empi pump, although it seems to work outside the van.
Current setup has 6 connections including tank and carbs. Old setup had 14 connections. So it's as simple as it can be right now. I've pretty much run out of things to change. If one last pump doesn't do it the problem must lie elsewhere.
When original mechanical pump started leaking we ran out of fuel. Could be dirt sucked into carbs, but would assume it wouldn't idle or run ok at slower speeds.
Oh well. Tomorrows another day.
Just thinking. I'm running the fuel pump off the coil. Could this be messing up the coil somehow?
Maybe getting delirious now and suspecting everything.
If it's running ok at lower speeds, I'd give serious consideration to the sparking part of the equation (coil/HT/distributor/timing). With the number of fuel pumps you've tried balance of odds are it has to be something else. You could then start looking at worn needles/floats but I doubt it's dirt in the carbs if you've checked filters and lines.
Not sure of your pump's relay requirements but generally speaking, I would expect coil +ve and -ve, chassis ground, battery 12v+ve and pump +. So, yes, I would expect to see wiring to the coil.
But coils do break down so maybe the switching from the dizzy is causing an issue.
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