Engine Tuning Blues

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M

MadH00ter

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22
Hey guys, been struggling with tuning my truck. Decided to go back to factory settings and re-tune with PureNitro's tuning guide. I have a used truck, x ss, engine is probably already well broken in (K4.6).
The problem I'm having is getting it started and keeping it running to get the temp up a bit. The truck does not want to take any throttle, it'll just flood and die. Well, I think that's what is happening.
So after clearing the fuel out of the engine, I start it up again, and I've just been pinching the carb line, and it'll rev up, and save the truck from bogging down and flooding and stalling.
Should I start tunning the HSN 1/12 turn at a time while it's on a stand until I can use the throttle and the truck will idle steady for a few seconds? Then drive it up and down the street at wot for a few passes and continue tuning until the idle stays high, then back off per the guide?

Hope I was able to give enough info, mostly just wondering if i am going in the right direction.
 
(does any one else start their savage while on a block in the off position?)

this allows you to control the throttle by hand and makes it much easier to warm up! just don't forget once its started turn on the rx then turn on the truck.

this may make it easier to get it warm so you can start tuning, and i agree w/max your too rich
 
you can leave the ignitor on to get it up to temp a bit but it will shorten the life of the plug alot. I recomend buying a few plugs for this process. You always want to make sure you are tuning with a good plug.
 
maximusraylius said:
don't start your truck with it turned off... the servo needs on so it runs the throttle like its supposed to so if it starts with it off you turn the truck on itll move the throtle and not be an acurate adjustment.....
Click to expand...

max not to disagree with ya but i have been starting my savage this way for a very long time i can adjust the amount of fuel by hand for a easy start (1-pull) and when i turn it on the servo takes controll just as it would if i had turned it on before i started it. ive never have had any problems, just easy starts every time.. is what I'm doing wrong?
 
The plug is brand new. I had a tune issue previously, needles must have out of whack, rich LSN and lean HSN. Was distorting brand new plugs and wrecking them. I'll keep going then, probably close now to getting it to run without it flooding and shutting the engine down.
Thanks for letting me know I'm headed in the right direction with it... btw, should I leave the LSN at flush until I finish tuning the HSN (just wondering if 1/12 or 2/12 turns lean would help the over rich settings)
 
If your engine won't idle at all, start by leaning the LSN at 1/12 turns until it will idle on it's own. Also make sure that you have a 1mm gap even with the brakes applied. One of the worst things to do is run an engine overly rich, it will put a lot of additional stress on the components and it won't get to temp putting even more stress on the engine.

As for starting the engine, you should give the carb just a little extra opening so it can high idle, this will make starting a whole lot easier. Either adjust your radio so it holds it open just a tad or leave the truck off and adjust the carb gap by hand, either way will work.
 
It'll idle, just boggs quickly and dies if I don't pinch the carb line to stop the fuel flow. As soon as I pinch the line, it'll start reving back up at which point I stop pinching, try a tiny bit of throttle, which boggs it right back down, then I do 1/12 turn leaner on HSN and try again.. when starting I do have the carb open slightly more than 1mm gap using the remote. I can start no problem, it just loads up quickly and doesn't wanna take any throttle.

At the moment i've gone about 1/4 turn lean or less on HSN and LSN at flush. (MSN I think is locked down flush btw)

At work now, will let you know if I have more problems or get it tunned next time I try it.

Thanks for all the replies!
 
PureNitro: If your engine won't idle at all, start by leaning the LSN at 1/12 turns until it will idle on it's own.

Should I do this before working on the HSN ?
 
Yes, the HSN has nothing to do with the idle so the only needle to play with for your idle setting is the LSN. When the LSN is set and you start giving it throttle, if it bogs and dies with throttle applied then it is time to work on the HSN.
 
Since I've already started leaning the HSN 1/4 +/- without touching the LSN. Should I start over and set back to flush. Then start leaning the LSN until it'll idle for 10-15 seconds. Then work on warming it up with WOT runs and then tune the HSN per the guide followed by tuning LSN per the guide.

Cool, I think I have a solid game plan if y'all agree with the above.

Thanks again for all the help
 
You might want to set the HSN back to factory settings and just work on the lsn for now. When the LSN is set properly the engine should be able to idle for the whole tank, if it won't then the LSN is still too rich.
 
Perfect! that explains why all my tuning attempts have failed thus far!
Lsn until I can idle for however long I want, and then start following your guide for the rest.

Thanks again all, sorry it took so many posts to get to this point.
 
LOL, no problem. One thing though, my tuning guide is for a fully broken in engine. Pull the plug and spin the flywheel, if there is any friction drag at TDC then the engine isn't ready for a full tune. Only if there is just a very tiny amount is the engine ready for the performance tune.
 
The LSN meters 100% of the fuel for your idle, all idle tuning is done strictly by the LSN. As soon as the carb opens is when the tuning transfers to the HSN directly, the LSN has no effect on performace or tune as the carb is opened.
 
:
Purenitro said:
The LSN meters 100% of the fuel for your idle, all idle tuning is done strictly by the LSN. As soon as the carb opens is when the tuning transfers to the HSN directly, the LSN has no effect on performace or tune as the carb is opened.
Click to expand...

wow! i was told wrong, i thought the lsn adjusted your take off power:duh:
 
It does, if it's too rich your launch will be soggy, too lean and it will be erratic, just right and it will have great launch and a smooth transition into the higher rpm.
 
NITROMITE said:
max not to disagree with ya but i have been starting my savage this way for a very long time i can adjust the amount of fuel by hand for a easy start (1-pull) and when i turn it on the servo takes controll just as it would if i had turned it on before i started it. ive never have had any problems, just easy starts every time.. is what I'm doing wrong?
Click to expand...


naaa its fine to disagree not an issue at all...lol but if its tuned right itll start no prob with truck turned on servos taking contol ect... if you need to start it by pulling on the carb slide .. just use trigger on controller not a prob....
 
Purenitro said:
The LSN meters 100% of the fuel for your idle, all idle tuning is done strictly by the LSN. As soon as the carb opens is when the tuning transfers to the HSN directly, the LSN has no effect on performace or tune as the carb is opened.
Click to expand...

Learn something new everyday...Nice info there Robin...
 
maximusraylius said:
naaa its fine to disagree not an issue at all...lol but if its tuned right itll start no prob with truck turned on servos taking contol ect... if you need to start it by pulling on the carb slide .. just use trigger on controller not a prob....
Click to expand...

ok! but when the rx is in my hand i cant keep the truck from jumping off the ground when i pull the pullstart!..lol thats why i like to do it buy hand it allows me to hold the truck down..lol..sry for interupting this thread..just seen the chance to ask...:chainkiller:
 
Dunno 'bout you, but I can grab the roll bar (body is usually off the truck for me due to my tuning woes) of my truck with me remote in hand. and when starting with wheels on the ground, I just put my left foot in front of the truck..

So back to tuning, I can get it to idle pretty well now (I think), and am able to run the truck around, but it seems to over heat or something and cut out, making me think that's it's lean somewhere. seems to happen after running some wot runs repeatedly, and doesn't seem to have the performance of my buddy's truck (same truck, but rtr).

I have the LSN as rich as I think it can be. I'm not sure if it's bringing the temp down at idle or not though (pointing temp gun down at the glow plug). Should the wheels turn at idle when the truck is on a stand, even after it's somewhat warm, like 140f-170f? It doesn't go anywhere when on pavement at idle either (I don't think, hard to remember this morning's tuning attempt in full detail), especially doesn't move on grass as idle.

Going to richen up the HSN a bit and do some WOT runs for about a half tank, if it'll stay running that long.

I may be trying to tune the truck to early too, like before it's fully warmed up. I havn't seen the temp go much over 200f, sometimes I see 220f, but that's the highest i've seen.

After wWOT run, the truck seems to go right back down to idle right away while I slow it down to turn around, it doesn't stay high reving at all.

I'm going to take it to a very large parking lot tomorrow and see what happens.

Just wondering what temp range should I look for before I start tuning?
 
No the wheels should not move at all when off the ground. That could mean that your idle is a little high. But you did mention that the truck goes right back to idle after a WOT run. I think its to rich thats why its cutting out. My truck is a pig when itsa cold. takes a little while for it to warm up. Once it's warm she runs great. I wouldn't start tuning it until you see your temps up in the 200 range. I fill her to half tank run her around to fully warm her up. Sometimes I'll run on the grass to heat her up quicker. Once shes warm about 215 or so I'll start tuning (if I need to) Hope that helps and If I'm wrong someone please correct me.
 
My truck doesn't even run that good at 200 degrees. It needs to be more like 220 for me before it doesn't sound like its struggling to wind up. It always sounds too rich until it's hot. I like to wait until it is like 230's to 240's before I change anything otherwise I find myself having to change it back as the motor temp gets higher.
 
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If your having a hard time getting over 200 degrees then your probably just on the rich side of a good tune. Lean it out in tiny increments and run the truck like you normally would and then check your temps. I like to check my temps under different circumstances. I check it right after a couple WOT passes where the engine is getting plenty of air flow, then I check it after some lower speed running where I am giving it short repeated bursts at full throttle, and then I like to check it with the truck at rest and the engine idling for a couple minutes. This gives me an idea of what the temp is doing under different driving conditions. If I see any temps I don't like then and can make small changes to fine tune it. Sometimes I have to make small changes every time I drive just because the weather is different, so keep in mind that you may need to make small adjustments periodically to keep it just right. You may get it perfect one day and the next it seems too rich.
 
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