Fuel delivery issue on Twin 45 DCOE's

**sleeky** · 20-06-2007, 04:37 PM

Originally Posted by Talasas

If it is the pump and you want to try, you can get an electric fuel pump from a Subaru EA82 engine, they are small, light and designed for carbies. They are cheap and work really well.

sounds alright, but itl come down to how much it can flow.. because i do have a heavy foot

**Dazza** · 20-06-2007, 09:23 PM

[QUOTE=sleeky]If i plant it, itl go, but it doesnt go anywhere near as hard as the 40mm solexs i had on there before, could it be to do with the tune/diff main jets etc? The pump has always worked well on my 40mm it only has been doing this when i got the 45s put on.

.You might be lacking acceleration because your engine doesn't have as much vaccum with the bigger carbys. You might need smaller chokes in the webers to give you some more vaccum

**allencr** · 21-06-2007, 01:32 AM

Originally Posted by sleeky

it stalls almost instantly..

I think you've got something else happening, because 'almost instantly' isn't something that can happen in any carb problem I can think of, but is something electrical.

Running out of fuel for whatever reason - pump, line capacity/clog/leak, pickup, vent is just not going to happen fast or suddenly, even to a sloth.

**30psi 4agte** · 21-06-2007, 03:34 AM

Some good posts in here ! + rep to the lucky (wise) ones.

If the pump is struggling to fill the fuel bowl and you hit a hill it could die pretty quick.

Having your fuel line disconnected from the carbs and only getting a trickle is not normal ...... So like previously mentioned:
Blockage somewhere ? i know you said you have had the tank out etc etc but try disconnecting the fuel line at the carbs and try blowing through it to see if it is blocked somewhere.

Fuel pump voltage ? have you checked it with a volt meter ? has it got solid connections to power and earth.

If all else fails mabe get / borrow an old pump from a mate to see if it fixes the prob or not. This way you wont waist money on a new pump only to find out the prob is else where

**lexsmaz** · 21-06-2007, 04:59 AM

Strange symptons .. was the dyno run done recently, whilst you were having the hill problems ? if it was dynoed with the problem, its not fuel related as some of the other guys have said .. it would have shown up straight away ... & use also say on the flat you can run at 60 or 100 even flat, out so again backs up its not fuel .. & dying down hills is not fuel related unless your really getting stuck into it .. sounds electrical, i would check in the engine bay around the distributor etc for any bad sort of bad / dodgy connections .. hook up a 12 volt test light to the positive side of your coil & run an extension wire so you can have it inside the car & earthed & working when you drive the car, also i would hook up a timing light to the coil lead, & again try & get the timing light inside the car ( could be a bit tricky ) or strapped to the bonnet or something with the button for the timing light taped on, and take it for a drive with the test light & timing light working, dont worry about flat roads just hit as many hills as you can ... As soon as the car dies off keep your foot on the accelerator & dont touch the clutch ( pressuming its a manual ) & then check out the crude tell tales, If the under bonnet electricals are ok, the test light will still be bright & not flickering or dying, & the timing light should still be flickering away strongly, again not dying off or any dead spots ... The reason i would hook up the timing light to to the coil lead is so you get more flashes per revolution and especially as its dying maybe easier to tell, but if you want, try a plug lead as well, probably for safety sake a passenger is not a bad idea, to keep an eye on everything, so you can just drive ? PS a volt meter on the coil would even be better ... more accurate ....
Good luck ... Rob ...

**lexsmaz** · 21-06-2007, 05:23 AM

I should have also mentioned that you need to hit the hills at 60 as a minimum, gives you more time to check out the tell tales, dont pull over straight away just let the car slow down, again looking at the tell tales, the timing light fashing will obviously start to reduce the flash rate, but should not faulter or stop until the engine stops turning over ..
Have fun ......
Rob ....