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Truck running like crap with body on

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J

jtboogie

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Houston Texas
RC Driving Style
  1. Bashing
Got my new T maxx a few weeks ago, and I have put about a gallon through it and I am only having one problem. When i start the truck up and drive it around for a little while, and then once its warmed up I have been running it without the body on and the truck runs great. I can ride wheelies for 100 feet and it is fast as hell at about 1 1/2 turns out on the low speed and 3 1/2 on the high speed when its not cold and a little below 2 turns out on the low speed and 4 1/4 on the high speed. Truck runs around 264, However when I put the body on the truck immediately starts to have an erratic idle. And then after about a minute of driving the engine is over heating. 290 to 309. I take the body off and the truck runs great. I figured I wasn't getting enough air so I washed my air filter and my LHS told me to only oil the primary filter and put the outer one on with no oil. Again truck seemed to run better with the new air filter set up with the body off, but then when the body went on OVERHEATING WITHIN A MINUTE. I then cut the grille out of the body thinking my air flow would increase , but I'm still having the same problem. Any advice is greatly appreciated.
 
Also try taking the outter filter off maybe fighting for air to much with body on had this problem with a Cen i used to have couldnt run a motor saver i believe thats what it was called over my original air filter or it was fighting for air
 
Less air in the engine would make it run rich at a performance tune. Which would make it run cooler. You'd have to lean the mixture to match the air flow, which would only result in a less powerful engine. Same as running a restricter. Probably nothing to do with this problem.
 
do you guys know where i can find out exactly where to cut on my tmaxx....and I've also see some guys runnin electric fans on there gas powered....n e words of wisdom on that
 
Newb86 said:
Also try taking the outter filter off maybe fighting for air to much with body on had this problem with a Cen i used to have couldnt run a motor saver i believe thats what it was called over my original air filter or it was fighting for air
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Dont take the outer filter off. Its there for a reason. They wouldnt supply it if it werent. Cut a hole in the "windshield" of your body, directly in front of the cooling head
 
cut the entire windshield and back window out, truck seemed to run slightly better, richened the settings a little and it runs better however I'm having the issue of running too rich because when going from a stop to just enough throttle to start rolling. it will run for about 2 seconds and then just shut off. I'm pretty sure this mean one of the settinga is too rich. I had the same problem when i got the truck. It was set too rich from the factory and would start rolling and then just shut off not flood but just shut right off, not stalling or spudering, and only from a dead stop to 1/2 throttle. a slight turn on the high speed needle to lean and it ran fine. I'm going to try tinkering with it some more tomorrow. I just dont understand why the truck isnt engineered to get the right air flow, and find that its a very big pain that the truck runs completely fine without the body, and then as soon as the body goes on i have to retune it over and over, and most of the time over heats.
 
jtboogie said:
cut the entire windshield and back window out, truck seemed to run slightly better, richened the settings a little and it runs better however I'm having the issue of running too rich because when going from a stop to just enough throttle to start rolling. it will run for about 2 seconds and then just shut off. I'm pretty sure this mean one of the settinga is too rich. I had the same problem when i got the truck. It was set too rich from the factory and would start rolling and then just shut off not flood but just shut right off, not stalling or spudering, and only from a dead stop to 1/2 throttle. a slight turn on the high speed needle to lean and it ran fine. I'm going to try tinkering with it some more tomorrow. I just dont understand why the truck isnt engineered to get the right air flow, and find that its a very big pain that the truck runs completely fine without the body, and then as soon as the body goes on i have to retune it over and over, and most of the time over heats.
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You didn't need to cut out the entire F&R windows, but that's OK. The truck is engineered just fine, you just need to spend some time tuning it is all. I know plenty of guys with T Maxx's that run great with the body on. Nitro RC is what helped me develop some patience years ago. If you want peak performance out of them, you have to tune ever so slightly each time you take them out for the current weather conditions. The exception would be my O.S. engine, unless there was a drastic change in ambient conditions, it held a tune like nothing I've ever owned.
 
just remembered about the weather. I had it runnig perfectly 2 days ago in 45 degree weather, and today when I was messing with it, The temp was 82. Damn Texas weather. I will tinker with it some more tomorrow with the body and let you guys know what happens.
 
jtboogie said:
just remembered about the weather. I had it runnig perfectly 2 days ago in 45 degree weather, and today when I was messing with it, The temp was 82. Damn Texas weather. I will tinker with it some more tomorrow with the body and let you guys know what happens.
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In that case, here's a tip for that. Colder air is denser and contains more oxygen and thus will need a richer needle setting. Warm air is thinner and has less oxygen, and as such will require a leaner needle setting. It's actually much more scientific than that, but for tuning purposes that will suffice. Good luck, and let us know how it comes out.

EDIT: When I lived in TX, the natives always told me "Don't like the weather? Stick around, it'll change in an hour." :D
 
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Yes it is practically true1 If you don't like the weather in Texas, wait an hour it will change. I live in North Texas and we do experience drastic changes. I find usually on the weekends I have time in late afternoon (after honeydo's and kids activiities) to go bashing. In the fall the sun sets around 5 pm. If I get out it seems I'm only tuning for 2-3 hours rather than having some true fun and bashing because of the drastic temperature drops.
 
same thing all i do is tune the entire run, make 4 passes, then tune, 4 more, then re-tune. And thats what I'm saying with the body on i, forget about it. I have yet to have 30 minutes of having fun without tuning 2 or 3 times, and have 1000 bucks in the truck
 
During the spring and summer months tuning and bashing is much easier in Texas, This past summer I have had several times where I would go out, get tuned and then have several goods hours of running without retunes needed. Fall is hard because of the wide temperature changes and the rate at which rhose temperatures change. For me winter is out of the question because last winter (my engine had less than 1.5 gallons through it) i destroyed my engine from having to run too rich. the excess fuel caused my con rod to split and then destroying the piston.
 
If your engine is giving you that much trouble tuning it in, it probably has a small air leak. Read the tuning tips and tricks at the top of the nitro forum. Take note of where your needle settings are and put them back. They should be in the ball park if the engine starts now. With a 40+ degree change in ambient temperature, expect to have some tuning to do. Once you get to know your engine better, you'll know where to set the needles for such a drastic change in temp.
 
Truck was runnig great today and then all of a sudden wouldn't shift into second. At one point truck was not even rolling forward with half throttle applied, engine revs up but over revs for how fast the truck is moving. and like I said no shift just bangs out in first and sounds like a car red lining. Don't know what I did, but something BROKE.
 
Make sure the slipper is tight enough.
For shutting down when you start from a stop, that's all in the LSN, NOT the HSN. After half throttle the HSN does the work.
Don't make any adjustments till it's warmed up. I can't tell if it's too rich or too lean without hearing it, but try it one way, drive it around, if it improves then fine tune it. If it doesn't improve or gets worse, adjust it the other way.
 

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