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carb or fuel pump
Posted: Wed Aug 11, 2010 6:11 pm
by cadetchris
still trying to put my HIF38 carb on primrose, but i simply cannot get it to work.
new ADS needle for it, cleaned thoroughly, but alas still nothing.
a squirt of petrol down the inlet manifold and the engine burst into life and stops (owing to no more petrol)
i have filled the pipe with petrol and then blown it down into the carb, this allows the engine to start and run for a few mins until i either run out of petrol or puff. yet when i reconnect the petrol pipe back upto the pump, i run down the battery trying to start it.
so, with a bit of pressure behind the petrol in the pipe, the car starts and runs for a short time, without it, nothing.
so, is it the carb thats iffy or the pump that simply dosent have enough power to feed the carb?
Re: carb or fuel pump
Posted: Wed Aug 11, 2010 7:02 pm
by aupickup
does the pump pump petrol
the pump will have enough power
Re: carb or fuel pump
Posted: Wed Aug 11, 2010 7:20 pm
by cadetchris
yep it pumps petrol, it works with the other carb on it, its just the HIF38 carb just dosent want to work. its annoying the spanners out of me.
Re: carb or fuel pump
Posted: Wed Aug 11, 2010 7:42 pm
by RobMoore
If the pump pumps fuel and works on the other carb I would be inclined to think the hi38 is where the fault lays.
Have you checked for any blockages in the hif38? are you using the same pipe from pump to carb?
Re: carb or fuel pump
Posted: Wed Aug 11, 2010 8:00 pm
by bmcecosse
And are you connecting the fuel pipe to the fuel inlet on the carb! ? I thought we had been down this road ages ago!
Re: carb or fuel pump
Posted: Wed Aug 11, 2010 8:30 pm
by cadetchris
yes, pipe connected to the right inlet, and its all clear throughout the pipes. they only way i actually got the thing to work was to put some pressure behind it.
Re: carb or fuel pump
Posted: Wed Aug 11, 2010 8:57 pm
by ferret76
Check the float needle, it may be stuck in the closed position or the float may be stuck holding the needle closed. I recently had exactly the same problem.
Re: carb or fuel pump
Posted: Thu Aug 12, 2010 12:12 pm
by cadetchris
checked that today, all moves freely. the reservoir fills with fuel, but it dosent get up into the engine. so, i am totally lost really.
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 8:10 am
by kennatt
[quote]i have filled the pipe with petrol and then blown it down into the carb, this allows the engine to start and run for a few mins until i either run out of petrol or puff. [quote] How,if the carb bowl is full of petrol the float and valve are working then it would be inpossible to blow into the carb as the valve would have closed it off,just curious

Re: carb or fuel pump
Posted: Fri Aug 13, 2010 9:56 am
by bmcecosse
I still think you are connecting to the wrong pipe on the carb - can't see what else would cause this - post us a picture.
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 10:02 am
by cadetchris
Curious indeed, well if you blow hard enough you force the petrol part the value, through the jet and into carb, this got the engine going for a while, untill all the petrol had gone.
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 10:04 am
by bmcecosse
I suspect you are 'blowing' through the vent pipe!
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 10:17 am
by cadetchris
Ill pop on a picture when i get home from work.
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 10:47 am
by Kevin
cadetchris wrote:Curious indeed, well if you blow hard enough you force the petrol part the value, through the jet and into carb, this got the engine going for a while, untill all the petrol had gone.
kennatt wrote:How,if the carb bowl is full of petrol the float and valve are working then it would be inpossible to blow into the carb as the valve would have closed it off,just curious
Agreed a photo may reveal more info as I am puzzled as well (not that that's dificult)
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 1:36 pm
by cadetchris
right, owing to it raining sideways, and the carb isnt on the car, have taken a photo of the carb's side with all the pipes, however the website dosent want to show it
of the three pipes, the lower pipe, i have been assured by several people and the SU carb book, is the inlet pipe, this has had the petrol pipe connected to it every time. the top left is the overflow and the top right is the breather pipe for the rocker.
so, when its all connected up, the pump pumps fuel into the carb, but it isnt adventurous enough to get up the jet and into the carb.
however, when i fill up the pipe and actually force the petrol into the carb, up the jet and into the carb throat, the engine runs,
so, why is my fuel not getting from the reservoir into the carb throat?
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 4:57 pm
by Kevin
Send me the photo and I will post it up for you.
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 4:59 pm
by cadetchris
how do i do that?
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 5:08 pm
by cadetchris
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 5:22 pm
by barrie102
Check the filter inside the carb, they can get blocked, blowing into carb has probably created enough pressure to allow fuel to pass the blockage.
Re: carb or fuel pump
Posted: Fri Aug 13, 2010 5:30 pm
by cadetchris
no filter in the carb, i have had it all to bits and cleaned it many many times.
i think my petrol isnt adventurous enough, it seems content with getting to the carb but not to the jet and beyond