Tmaxx 3.3 Engine sputter

[Spikes32]

I took the truck for a spin yesterday and had this bad sputter on hard acceleration. The mixture setting seemed to be on the rich side as seen by the thick smoke trail, but not sure. I started out with the factory 4 turns out on the hsn and a flush lsn. Do I just need to lean it out more in small increments?

I have attached a link to a video I posted on Youtube where you can hear the engine sputtering.

[ame="http://www.youtube.com/watch?v=w46unSGdLQg"]Tmaxx Sputter - Any Ideas?? - YouTube[/ame]

 

[hotrodrob]

Yes lean in small increments and make a few high speed passes ,do this until you do not notice an increase in performance,then back off the needle a little so as to keep the engine in the safe zone,after that you can go after the lsn and adjust as necisary

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[Snook Man]

Thats a lean bog, not a rich bog. Richen the HSN and maybe even the LSN if still needed...

 

[Spikes32]

Ok, I'll try and richen it up a little at a time and see how that goes; I did find a few air bubbles coming from around the glow plug just before I ran out of fuel, could this also have contributed top the sputtering?

 

[hotrodrob]

Bubbles from Around glow plug was it loose? Go with snooks advice I cannot pull up your vidio

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[dub c]

lean high side. Props to you for being able to post a short vid! And yes, bubbles around the plug is bad. fix that before trying to retune.

 

[2revo1maxx]

Oh yeah she's running very lean. Always richen the hsn whenever you're in doubt. Fix the glow plug sealing issue, and make sure your exhaust system is tight and providing enough pressure to the tank.

You should never assume the stock settings are good enough, that's just a starting point.

 

[Spikes32]

Thanks for the help guys, the glow plug wasn't tight enough and was seeping by the copper sealing washer, richebed it up too and it seems ok. I was really thrown with all the smoke coming from the exhaust thinking it was too rich. I still get an intermittent sputter but only with less than a half tank full of fuel. Can it be air pockets on the fuel lines caused by a low tank level with the fuel sloshing around and possibly creating foaming/aeration of the fuel by the pick up?

 

[2revo1maxx]

It could still be too lean, have an exhaust leak, or a loose or missing fuel tank screw.
If the tank and exhaust check out ok I would continue to richen the needle until you know for sure that it's running too rich, then slowly lean it back in to good performance. Performance is the key, don't be fooled by smoke trails, you want to look for performance. Always go rich whenever you are unsure of the tune.

 

[hotrodrob]

Does it have a high idle after a wot pass?

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[Spikes32]

After high speed runs the idle seems fine, not excessively high. Also the fuel tank screws are all tight and as far as I can tell there are no exhaust leaks. I was sure positive the truck was rich due to the smoke, I appreciate the insight in regards not being fooled by the smoke trail, there is definitely a learning curve with these things.

 

[2revo1maxx]

It can take some time to learn what they sound like and how they're supposed to act.

 

[ksrichard]

Try using the "nitro tuning tips and flow chart". Its simple and it works. There are tons of vids on tuning on youtube "squirrelod" has a good series.