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Old 07-09-2009, 11:57 AM   #1
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Default 2.4mhz glitches only with nitro engine running..

new to 2.4, i picked up a DX3.0 off the local classifieds. the owner showed me how to bind the radio and its been working great for the past 2 weeks. (since ive had it)

yesterday, and the day before, ive noticed alot of consistent glitching which once made me go off a huge jump at the track, and almost clear the fence. quite scary. (broke some stuff too)

now while putting around the block, its still pretty consistent at low speeds, and is now effecting the steering also.

with the engine off.. everything is great. steering and throttle is trouble free. i can play with the servo's for hours, and no issue.

as soon as i start the engine, while ripping it on the stand, the throttle servo would go to hard brake, and sometimes the steering would glitch.

only with engine running... am i missing something?
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Old 07-09-2009, 12:19 PM   #2
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Sounds like a grounding problem to me. Some metal contact is being made. The first place I would check is the wire for the steering servo getting to close to the spur gear. Then check all the wires inside your box to be sure.
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Old 07-09-2009, 12:21 PM   #3
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This isn't a answer for your question, but my 2.4 setup sometimes glitches too. On two occasions in two different parking lots I've lost signal for a few seconds. It scary. I was not at a long distance. Make sure you intenna is all the way out and keep your reciever clean. Best answer I could give ya.
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Old 07-09-2009, 01:45 PM   #4
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well, the best test i could do is like at the school parking lot, or field.. somewhere thats pretty rural.

this is consistent at my house.. and at the track.. which never were a problem until recently. and even more mind boggling.. only when the engine is running.

im going down to the hobbyshop, ive become pretty good friends with the staff.. and they're going to take a look at it. ive even considered running a ground from the neg. battery to an engine bolt.. i have no clue where to begin.
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Old 07-09-2009, 01:50 PM   #5
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Sounds like a break in the ant, or a cold joint on the board of the receiver.
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Old 07-09-2009, 01:54 PM   #6
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well, you said receiver.. and not radio.. because, ive tried my 2nd receiver with same results.. i only have 1 radio.

i'll update the thread later.. hopefully one of the guys at the shop have another 2.4 radio, they can bind up with my truggy and see if we can eliminate some questions.
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Old 07-09-2009, 02:04 PM   #7
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Is it a Spektrum? I had a SR3300T that went the same way - I RMAed it to Spektrum, still waiting on the replacement.

I did have an issue with the negative cable on battery pack once - it made it look glitchy while the motor was running - the cable was broken internally and the vibration made it break contact; but that was a different receiver... I fixed the cable no more issues -
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Old 07-09-2009, 05:37 PM   #8
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ok.. well i think ive solved it.

i went to a wide open field... got it going. ran great in close range. once i started to get further away, my worst nightmare came true. that fucker boned out!

1st issue.. out of 2.

when binding. you bind the receiver 1st. then run the controls as you would fail safe while binding the transmitter. ok. however, once i got my binding done, i realized my throttle servo was backwards. i flipped it on the radio. IT DOESN'T FLIP THE FAIL SAFE! this whole time i was going out of range, the fail safe was working, but going full throttle, not brake. thats a dumb mistake.

luckily each time its done it, the truck has flipped over, or got stuck, and ive been able to cut the fuel. i dont think my piston and sleeve is toast yet, it still runs, and isn't as loose as my high school GF.

2nd issue remember i had the glitching problem on the stand. ONLY while engine running. well, after not understanding, i figured i would visually inspect all my wires, and see if anything is out of the ordinary. WITH ENGINE OFF, i started playing with wires. i toggled the switch back and forth, nothing. i looked at the battery wires to receiver... nothing. went to that little red BEC (i think) plug right off the battery... BINGO! once in a while, even though its fully inserted, the contacts would come loose inside. i could do it manually with engine off, and duplicate the same problems.

so i broke the plug down, bent the female tabs inside, and plugged it back up, nice and firm, no flinch.

so long story short. my range was prolly fine. at the track, my fail safe was set backwards. and all along, i was having a battery problem to my receiver.

its been driving me nuts for the past 4 days.
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Old 07-09-2009, 05:50 PM   #9
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Isn`t it great when you get this sort of pain in the a#s problem sorted
I had the same sort of deal going on with my spectrum,strange glitching etc.
It turned out to be not enough padding around the RX which slowly destroyed the RX. Be sure to wrap that RX nice and cosy so it doesn`t bash itself to death.
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Old 07-09-2009, 05:58 PM   #10
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oh yeah.. i have plenty of foam inside my radio box. that thing sint' moving at all.

yeah, im looking forward to enjoy 2.4ghz again. i finally got framilure with my local track, taking some of the jumps even. alot different coming from a onroad basher history.

side note.. once getting home, and 2-3 run-a-ways.. im having a hard time tuning the motor. i got great high needle power, sluggesh low end. and im having a hard time tuning the LSN once its warmed up.

i popped the motor out, to give it a soap sud test.. and i have a few leaks. its leaking on both sides of the carb pinch bolt. i think thats easy.. but i have a bigger leak behind the flywheel.

i don't know if thats why its erratic, or loss of low end power. so im going to research my engine break down for the flywheel seal.
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Old 07-09-2009, 08:05 PM   #11
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Leaks behind the flywheel indicate a bad front bearing. Time to replace it. A friend of mine has some issues with tuning and when he replaced the bearing the motor was like new. May want to consider replacing the front and rear crankcase bearing.
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Old 07-09-2009, 08:13 PM   #12
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cool, i'll keep it in mind. the motor runs good.. just alittle finicky on tuning.

i just started another thread, but i figure i might ask here as well, since some of you guys are following the thread.

even after the couple of run aways, it still runs pretty strong. so after solving the radio issue, i figured ide go out and enjoy some neighborhood bashing.

the motor rips good. spinning tires off the line. but still haven't got the courage to get the temps up to 240. 190-200ish. power is great. lots of smoke..

but.. my last 1/4 tank.. i loose alot of low end power. it starts to get sluggish off the line, but my HSN is still lots of power.

is it because the engine is warming up, and my tune is off? or is it that 1/4 tank left shifting forward away from the pick up, and leaning my LSN?

again. my on road will run HARD till the tank is dry. but it doesn't have the chassis movement this truggy has. so is that a common gripe?
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