fuel pressure problem
 

Hi,
Can someone help me with yet another problem I am having with this engine that I have been breaking in for what seems like a life time. It would appear that fuel won't stay in the pipe and / or engine. It seems that the system won't stay pressurised and the fuel in the pipe just runs back into the tank. Anyone any idea why this might be happening ?

Thanks for your help.

Regards,

32819toon

I had this problem with a stadium truck, I raised the fuel tank up about 10mm and put a puel filter in the exhaust pressure line, seemed to fix the problem

Hello,
What motor are you trying to run in? :)

It's a Thunder Tiger .15 in a DT10 buggy, and it has been a real pain in the arse. I've put the fuel filter in and I can see the logic in the raising of the tank as I feel part of the problem is the height and distance the fuel is having to travel to the pipe.

Thanks for the advise.

do you have the same problem with the body on and off the buggy?

i know the 8th scale rtr t/tigers that some of the new guys run at our track have a problem with the exhaust moving allowng the body to pinch off the pressure line returning from the exhaust which causes them to flame out.

sorry if this is not your problem here, just fuel for thought...:tire:

Hi Dynamite - body on - I wish !! this baby hasn't even seen its body yet !!
I'll bear your comments in mind though and thanks for your help.

what exactly happens to your engine mate? does it just die after start up?

if it just keeps flaming out other then maybe having idle set to low, increase idle by 1/4 turn and see what happens if still nothing then you could try pressure testing your system.

take off line from carby and pipe outlet block one end of the lines and presurise see if you have a leak - then check pipe that pressure nipple is not blocked.

see how you go.

yup

:confused:

Hi,
I get it running and the idle seems to be OK. It just dies during running and when I look at the fuel line, it's empty. That's why I think that there is some problem with the fuel system as I can't keep fuel running to the engine.

a few things id like to ask.
is the car new ? is the fuel tank seal in good condition ?
when idling, do you know the temp, and how long are you idling it for ?
is there any fuel leaks wetness anywhere ? and if its a side exhaust, is the gasket new and no leaks ?
when idling for so long a motor can fuel up. when you hit the gas it dies, due to excess fuel. if you can idle for a minuet or so, and hit the gas and it revvs fairly quickly before it dies, then try to richen the bottom end. what can be happening is the temps are too hot, and with a lean needle setting the fuel may not flow properly from the tank and seem to have air in the line.
i run a nova 12, and if the temps get up there, it can be a pain to restart, and have these symptoms as well. mainly caused by heat, and the fuel evaporates inthe carb and line before it enters the engine. a few things to take in i know, but more info would be great. :)

Hi Pattojnr,
Thanks for your help. I don't know the temp, but the other symptoms you mention are quite accurate. The car is brand new, and when I ran it the other day, it was the first time it had turned a wheel. I think I'll start by richening it up a bit and I'll let you know how I get on.
Thanks again,
32819toon

that dude is there only to increase his post count

UPDATE
 

UPDATE

The problem appears to be the fuel line between the tank and the carb. I can get fuel into the engine, but as soon as I stop priming, the fuel runs back down the pipe.

Also, I don't know if it's connected, but there was a puddle of fuel on the chassis. It would appear that fuel is leaking from the pipe connection to the tank even though I have it fixed tight with a cable tie. Is there a better way of securing the fuel pipe ?

Thanks for your help guys.

regards,
32819toon

Not sure if this question has been asked, but it could be the pipe. I have seen new pipes defective from the start. They do not create back presure so some reason. Maybe just try another pipe to see.