R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro On-Road > Onroad Nitro Engine Zone

Reply
 
Thread Tools Search this Thread
Old 04-21-2007, 02:56 PM   #1
Tech Addict
 
32819toon's Avatar
 
Join Date: Mar 2006
Location: North of England
Posts: 580
Trader Rating: 1 (100%+)
Default 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
32819toon is offline   Reply With Quote
Old 04-21-2007, 03:55 PM   #2
Tech Elite
 
Join Date: Dec 2006
Location: Brisbane
Posts: 3,154
Trader Rating: 28 (100%+)
Default

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
Ashley Cobb is offline   Reply With Quote
Old 04-22-2007, 07:29 AM   #3
Tech Adept
 
vc05hdt's Avatar
 
Join Date: Jul 2006
Location: Morley,Perth W.A.
Posts: 246
Default

Quote:
Originally Posted by 32819toon
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
Hello,
What motor are you trying to run in?
vc05hdt is offline   Reply With Quote
Old 04-22-2007, 03:00 PM   #4
Tech Addict
 
32819toon's Avatar
 
Join Date: Mar 2006
Location: North of England
Posts: 580
Trader Rating: 1 (100%+)
Default

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.
32819toon is offline   Reply With Quote
Old 04-23-2007, 06:20 AM   #5
Tech Addict
 
Dynamite's Avatar
 
Join Date: May 2004
Location: Australia
Posts: 614
Send a message via MSN to Dynamite
Default

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...
__________________
www.racingfactory.org
Kyosho RRR Evo | Sirio Evo III STI | Ko Radio
Dynamite is offline   Reply With Quote
Old 04-23-2007, 07:20 AM   #6
Tech Addict
 
32819toon's Avatar
 
Join Date: Mar 2006
Location: North of England
Posts: 580
Trader Rating: 1 (100%+)
Default

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.
32819toon is offline   Reply With Quote
Old 04-23-2007, 03:35 PM   #7
Tech Addict
 
Dynamite's Avatar
 
Join Date: May 2004
Location: Australia
Posts: 614
Send a message via MSN to Dynamite
Default

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.
__________________
www.racingfactory.org
Kyosho RRR Evo | Sirio Evo III STI | Ko Radio
Dynamite is offline   Reply With Quote
Old 04-23-2007, 09:08 PM   #8
Tech Adept
 
kyosho 444's Avatar
 
Join Date: Apr 2007
Posts: 172
Default

yup
kyosho 444 is offline   Reply With Quote
Old 04-23-2007, 10:26 PM   #9
Tech Adept
 
nitrothugg's Avatar
 
Join Date: Oct 2003
Location: Chicago by way of NY
Posts: 195
Default

Quote:
Originally Posted by kyosho 444
yup

nitrothugg is offline   Reply With Quote
Old 04-24-2007, 04:46 AM   #10
Tech Addict
 
32819toon's Avatar
 
Join Date: Mar 2006
Location: North of England
Posts: 580
Trader Rating: 1 (100%+)
Default

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.
32819toon is offline   Reply With Quote
Old 04-24-2007, 05:03 AM   #11
Tech Elite
 
Pattojnr's Avatar
 
Join Date: Apr 2006
Location: Perth Australia
Posts: 4,594
Trader Rating: 19 (100%+)
Default

Quote:
Originally Posted by 32819toon
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.
__________________
Serpent - Walter RC
Serpent E Power ..... Serpent 747 Reds M3T
Serpent 966-TE Reds M7T .... S411ERYX Speedpassion 3.5T, T-Shox
Serpent 811-TE REDs R5T
Pattojnr is offline   Reply With Quote
Old 04-24-2007, 07:52 AM   #12
Tech Addict
 
32819toon's Avatar
 
Join Date: Mar 2006
Location: North of England
Posts: 580
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by Pattojnr
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
32819toon is offline   Reply With Quote
Old 04-24-2007, 02:50 PM   #13
Tech Addict
 
Join Date: Jan 2007
Posts: 660
Default

Quote:
Originally Posted by nitrothugg
that dude is there only to increase his post count
__________________
Kyosho V-One RRR - JP Modified Mugen X12 - GQ Racing Tires - Futaba servos - KO Helios w/Spektrum Pro - Maxy's Fuel
Losi 8ight 2.0 RTR for fun times
Dredd is offline   Reply With Quote
Old 05-05-2007, 01:24 PM   #14
Tech Addict
 
32819toon's Avatar
 
Join Date: Mar 2006
Location: North of England
Posts: 580
Trader Rating: 1 (100%+)
Default 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
32819toon is offline   Reply With Quote
Old 05-05-2007, 02:02 PM   #15
Tech Elite
 
dj apolaro's Avatar
 
Join Date: May 2005
Location: Miami, Fl.
Posts: 2,399
Default

Quote:
Originally Posted by 32819toon
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
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.
dj apolaro is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Return fuel tubing length - how to lower pressure in tank charlesd Onroad Nitro Engine Zone 3 06-13-2008 11:32 PM
Need help with no fuel pressure problem pumpkinfish Nitro Off-Road 12 08-05-2007 10:44 AM
pressure line to the fuel tank?? kris NZ Rookie Zone 9 08-01-2005 12:58 AM
Pressure inside fuel tank... Raycer Nitro On-Road 10 06-10-2004 02:25 AM
Fuel pressure DrIfT'R' Onroad Nitro Engine Zone 1 05-21-2004 09:36 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:45 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net