carb or fuel pump

[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?

[aupickup]

does the pump pump petrol
the pump will have enough power

[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.

[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?

[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!

[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.

[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.

[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.

[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

[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.

[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.

[bmcecosse]

I suspect you are 'blowing' through the vent pipe!

[cadetchris]

Ill pop on a picture when i get home from work.

[Kevin]

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.

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)

[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?

[Kevin]

Send me the photo and I will post it up for you.

[cadetchris]

how do i do that?

[cadetchris]

http://s106.photobucket.com/albums/m259 ... 0_0393.jpg

sorted, here it is

[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.

[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