3 cyclinder fire, possibly 40s trouble

[johnny27]

Having trouble with my nova and can't for the life of me find out whats wrong. When the engine warms up, the car won't take full throttle it just starts to die out, its spluttering and sounds like its off a cyclinder, but the car runs fine when cold. Tried changing new coil, new dizzy, new HT leads and plugs and still no further. Narrows it down to fuel problem, I know the webber 40s have different cicruits is it possible the circuit is faulty the one after the idle stage? Blocked jets? Is it hard to get the jets out of the 40s i know there is a few at the top of the carbs easy to take out, what about the rest? Anyhow any help is greatly appericated as I'm at my wits end with it, tried everything. Cheers

[alxlaw]

from what you'v said it sounds like the exact same thing that happend to my fiesta once it was warm n revved it would start to die, it turned out to be the fule pump, it was stuck in one position apparently, so i replaced it n it ran fine, but then agen it was a 1 ltr and i dont kno what size engine you'v got, or weather its injected n e way m8 hope iv not been compleetly useles


(n yes i do need a dictionary)

[johnny27]

Thanks for the idea i think i've one lying about somewhere spare. BTW its a 1200, twin webber 40s. Anyone know about the fuel circuits or jets being clogged? And incase anyones wondering the carbs have'nt been setup percisely to my engine but very close, and they were always running fine before. cheers

[-Bruce-]

have you just built the engine up? or has it just started to not rev up correctly recently?

does it idle ok when hot? and just die when you use thottle?

its easy to take the jets out. take the butterfly off the top cover on them. them take out the jet assemblys under all 4 skrew covers. and clean them with petrol and refit them.

then look for the pump jets and clean them. pic below of the pump jet location.
http://img.photobucket.com/albums/v256/broos3/carstuff050idlejet.jpg
bruce

[johnny27]

The engine was'nt rebuilt and was working fine untill recently, it actually idles fine when hot, just won't rev up. That picture is really helpful, i'll clean them tomorrow, always wanted to know where the pump jets are on the carbs. Thanks very much bruce. BTW does it sound like clogged jets to you?
There are so many jets on the webbers compared to the 2E3 twinchoke, complicated stuff. Cheers

[-Bruce-]

im not sure if its blocked jets mate. you might aswell have a look at them anyway.

have a look what is printed on all the jets and make sure that the same size jetts are in the relevent assemblys.

im not sure mate as if the jets were blocked the carbs would not function when cold. sorry i cnat be of much help

bruce

[m.d.]

my old 1.6 t40 engine did this and it was the weights in the dizzy had fallen off so when you reved it the timing retarded so much it died, seing as tho you have a new dizzy id try another one before you say its deffo a fueling problem, may have a dodgy dizzy as it does happen

[johnny27]

the dizzy was brand new. Does the fuel pump ever give any trouble or would it be likely to cause this?

[-Bruce-]

the fuel presure valve could be gettin stuck shut!! im realy not sure mate as i would have thought all these things would hapen both when hot and cold. :?

bruce

[johnny27]

Sourced the problem, there's no fuel getting to the pump, guessing the gauze filter in the tank is clogged, is it hard to remove with the fuel tank still on the car? Tried sucking on the line and getting nothing and priming the pump manually but with no results. btw yes there's petrol in the tank lol.

[-Bruce-]

lol so it was nothing to do with the carbs then. had a feeling that they would be ok. they dont just not work like that. they are simple when you break it all down.

bruce

[johnny27]

and sorry i forgot to mention the car is'nt starting at all now, any ideas about how to get the fuel filter off the tank, thanks

[novahead]

hi m8, there could just be a spilt in the fuel line and the pump is just suckin up air, check the fuel line, it only has to be a small hole,

just a thought


kev

[johnny27]

cheers man i'll do that. Incase there is, would it be safe to by second hand ones? Now that you mention it, when the engine was playing up, it sounded as if it was running way to lean, it was even poping spitting and banging taking over, so i checked the air/fuel mixture on the carbs but they were fine, thanks for the idea.

[novahead]

its probly spilt line and when u removed the pipes, it make it 2 times as bad so now theres no fuel at all getin up, just have a good look over the lines,
u may as well buy new its not that much, i dont think anyway



kev

[m.d.]

try re-ballancing them mate,

[johnny27]

Cleaned the jets yesterday, and some of them were tottaly blocked with dirt. So thats probaly why the car was'nt going properly. The cause is probaly dirty fuel tank. So i bought a inline fuel filter for the fuel line. Before i try to clean the tank i think i'll try switch on the electric fuel pump in the tank (my nova used to be a spi) since its high pressure it might be able to pickup the fuel, and i'll disconnect the carb fuel line to see if it pumps. And if it works i'll dissconect it and use my mechincal one. BTW is it possible to use the electric pump in the tank instead of the mechinal one if i fit a pressure regulator? has any one done this? thanks guys

[-Bruce-]

if you say the jets were blocked then clean out the float chamber, as there will be dirt in that and it will block the jets again when you start it. try not to break the top plate gasket, think if it has never been changed before then it should be a rubbery sort of material.

bruce