R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 02-05-2009, 03:55 AM   #1
Tech Regular
 
mini696's Avatar
 
Join Date: Mar 2004
Location: AUSTRALIA
Posts: 304
Default Stalling after pitting.

OK... Common question time.



My car has now begun to develope a habit of stalling if I gun the throttle hard after pitting. I have to do a lap being ginger on the throttle otherwise the car gets a free lift back to the pits.



What could be causing this?
__________________
D8, GO 5Port
Ve8, RX8 1900, Promatch 5100 4S
SC10, Hobbywing EzRun
mini696 is offline   Reply With Quote
Old 02-05-2009, 04:23 AM   #2
Tech Fanatic
 
Join Date: Jan 2008
Location: All Over So. Fla.
Posts: 985
Trader Rating: 1 (100%+)
Default

Unless you have air leaks your fuel line from the tank to the motor is to short.
The Working Man is offline   Reply With Quote
Old 02-05-2009, 04:30 AM   #3
Tech Regular
 
mini696's Avatar
 
Join Date: Mar 2004
Location: AUSTRALIA
Posts: 304
Default

Quote:
Originally Posted by The Working Man View Post
Unless you have air leaks your fuel line from the tank to the motor is to short.
No air leaks. I test for that every outing.

How does a longer fuel line help.

My line is quite long already, so maybe I have missed an air leak...

Could be engine tune though.
__________________
D8, GO 5Port
Ve8, RX8 1900, Promatch 5100 4S
SC10, Hobbywing EzRun
mini696 is offline   Reply With Quote
Old 02-05-2009, 04:46 AM   #4
Tech Regular
 
bjr48's Avatar
 
Join Date: Apr 2008
Posts: 274
Default

Just two guesses -
If it's tuning - bottom end is a little off, probably rich.
You are over filling the tank?

Hope you find it soon. I've expereinced the opposite - runaway throttle when pitting and it took me a couple of weeks to find the air leak. You obviously have a different problem but just as frustrating. good luck
bjr48 is offline   Reply With Quote
Old 02-05-2009, 08:03 AM   #5
Tech Adept
 
kevinmajor's Avatar
 
Join Date: May 2007
Posts: 192
Trader Rating: 3 (100%+)
Default

A full tank of fuel gives the engine a richer feel than a tank that is half full. As the tank empties, it will lean out. So, it sounds like your bottom end is on the rich side. Try the pinch test by pinching the fuel tube about 1 inch from the inlet to the carb. The engine should run for about 3-5 seconds. If it runs longer than that, you are too rich and should lean the bottom at about 1/8th turn each time. Keep doing that test untill you get within the 3-5 second window.
kevinmajor is offline   Reply With Quote
Old 02-05-2009, 08:10 AM   #6
Tech Elite
 
Join Date: Feb 2007
Location: USA
Posts: 2,756
Trader Rating: 66 (99%+)
Default

+1 to above post^^
sounds like the low end is loading up.
pwnzor is offline   Reply With Quote
Old 02-05-2009, 09:41 AM   #7
Tech Elite
 
Join Date: Oct 2004
Location: Michigan
Posts: 3,295
Trader Rating: 27 (100%+)
Default

Try pitting a lap earlier and see if it still does it. Could be getting to lean when the tank nears empty, or just coming in to close to empty all together.
__________________
Team Associated & CRC
Trackstar & Hobbywing esc's
Spektrum radios, GensAce batts, turnigy servos.
Keeping racing fun and affordable with my 8y.o. twins :)
The best track I've raced is the one in my backyard!
jbrow1 is offline   Reply With Quote
Old 02-05-2009, 10:28 AM   #8
Tech Regular
 
CHogle's Avatar
 
Join Date: Oct 2007
Location: Dayton, Ohio
Posts: 323
Trader Rating: 7 (100%+)
Send a message via MSN to CHogle
Default

Are you running the d8 or losi, look at number 3 if you are

you could be having one or maltiple of the following issues

1.rich low end needle
2.air leak

3.the tank in the d8 and the losi is a little differant than than normal. the fuel leaves the tank at a lower exit point. when your at the end of a tank and you refill the car quickly the tank self primes. so you go from running with air bubbles in most of your line to solid guel and this loads up your engine.

i found that if you mount a fuel filter on your line it will increse runtime a little for when your cutting it close on fuel. also i feel that fuel filters allow a more consistent fuel flow to your engine this should also lessen the amount that your tank self primes.

the second thing that ive found to work well, is to mount you fuel line so it above the fuel exit point of the fuel tank. this will eleminate the tanks self priming, and make you engine more consistent.

i would look at the tank last. make sure that you do not have a air leak or something stupid thats messing with the engine gitting to little or to much fuel.

bast of luck, hopefully you get it figured out
__________________
C.HOGLE
Serpent America, Novarossi, O'Donnnell fuel, PT Racing Oils, SMC, H-bomb Designs, Stick it 1 racing, Motor Savor Filters, Fastraxx Hobbies
CHogle is offline   Reply With Quote
Old 02-05-2009, 10:50 AM   #9
Tech Master
 
Join Date: Jul 2006
Location: Sugar Land, TX
Posts: 1,169
Trader Rating: 9 (100%+)
Default

Be sure to clear your engine out after it's fueled. Have your pit guy hold it up for half a second or so and give it a couple good revs before he sets it down.
cjtamu is offline   Reply With Quote
Old 02-05-2009, 11:06 AM   #10
Tech Champion
 
losi_racer's Avatar
R/C Tech Elite Subscriber
 
Join Date: Nov 2008
Location: mesa,az
Posts: 6,470
Trader Rating: 25 (100%+)
Default

Quote:
Originally Posted by cjtamu View Post
Be sure to clear your engine out after it's fueled. Have your pit guy hold it up for half a second or so and give it a couple good revs before he sets it down.

thats just wasted time, unless you have a system going which would never be 100% right your pit guy would get hurt. if your buggy is doing somethin it not supposed to do then you need to fix the problem. which most people have said that its to rich and i must agree
__________________

Byron Fuels/AKA Tires/Radiopost/TKO/Viper Rc/Dialed Inc/Empire Metal Product/Advantage Racing Products
losi_racer is offline   Reply With Quote
Old 02-05-2009, 03:03 PM   #11
Tech Addict
 
Join Date: Feb 2009
Posts: 609
Trader Rating: 1 (100%+)
Default

Had the same problem w/ my sons buggy. After replacing fuel lines it's o.k. What i think was happening was the fuel line was a little soft or possible pin hole & it would not presurize the tank quik enough. When i got the buggy there was no fuel in the line. It also seemed to take too long to fill the line when first starting after running out of fuel. Hope that helps. Let us know what fixes it.
romax is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
WERKS RACING (Malaysia) - updates, comments, enquiries, feedbacks and ask our drivers spencer Malaysian R/C Racers 355 10-26-2008 09:16 PM
Pitting Trick to blow the competition V1-RRR-WC Nitro On-Road 21 07-17-2007 06:56 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 02:02 AM.


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