Interfirence when engine is on

[Jaap]

Hello,

I am driving my new XB808 XRay buggy in the parking lot to break in the engine but after 4 tanks of fuel the buggy is not responding correctly. Basically when I brake and steer at the same time or brake and release the throttle stick, the steering and throttle go crazy.

I hold it in the air and I press full throttle and then brake and turn right and I see the receiver light turns red from green thus losing contact with transmitter and then the buggy of course goes crazy. My transmitter is a Futaba 3VCS 2.4 Ghz and I synched the transmitter with the receiver a couple of times to make sure it wasn't the problem.

I have sent the Futaba receiver to Futaba service center and they say there is no problem with it. They said it might be the 12Kg Savox servos drawing to much current which the receiver can't handle. I took the receiver to an electrician and he reenforced the wiring to be able to draw more current. I also checked the receiver battery with a battery checker after I charged it overnight and it is Fully Charged!

The problem occurs when the engine is ON and not when it is OFF.

Please help! All equipment are brand new and its been 6 months now that I can't get this fixed!

Thanks

 

[MotoGod]

What kind of RX Battery are you running? AAs? Nimh RX Pack? 4 cell? 5 cell? LIPO? Could just be the batteries not providing enough juice to run everything.

 

[Jaap]

What kind of RX Battery are you running? AAs? Nimh RX Pack? 4 cell? 5 cell? LIPO? Could just be the batteries not providing enough juice to run everything.

It is a 5 cell Nimh 6v. I have checked it with a battery checker and it says it is fully charged.

 

[MotoGod]

Is it reading 6V+ though? You could have a bad cell in there causing a voltage drop...and causing you headaches.

 

[frickenjoey]

Ok I had the EXACT same problem and mine was the receiver pack. I had a loose connection in it and it would only mess up when the engine was running. I even sent the receiver back to Futaba as well get it back and same crap. It was so intermittent too. Took several run-a-ways to figure it out. It charged good held power....until I ran it. It would be good for a while then it would freak out and always full throttle! The contact one one of the batteries was loose...it would work great until it heated up a bit and then with vibration it would loose contact and bye bye truggy. Check that...could be the same thing. Good luck.

 

[Rolex]

I agree. If you've already had the Rx checked out, it's almost 100% that there's a bad cell or a loose contact in the batt pack.
You can do a cheap test by connecting the 4AA pack and seeing if it still does it. I'm pretty certain it won't.

 

[Jaap]

I know that my battery has a capacity of 1600 mA but when I discharged it completely and charged it again the charger indicates that it charged it with 980 mA. Does that seem odd?

Also when I begun to discharge the battery, the battery checker indicated that the battery wasn't "safe" and it was in the "attention" levels and I only used the battery for 3-4 minutes of buggy runtime. Does that seem odd as well?

 

[MotoGod]

Yup. Sounds like it's either old, or has loose/dead cell(s) in there as well. Try a new pack or a AA pack if you have one handy.