Earthquake 3.5 followup problem: engine shuts off without glow starter
#1
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Earthquake 3.5 followup problem: engine shuts off without glow starter
I just payed to fix the clutch for the truck, and now I have this odd problem that the engine shuts off within a second or 2 if i take out the glow starter. It's not the glow plug (i don't think) as I've tried several working ones- and i've tried several glow starters as well. I heard that the LSN might be too rich BUT even when i turned it clockwise 2 rotations, the same problem persisted. Yesterday, By some miracle (changing idle speed if i remember correctly), I had the engine run without the starter for about a minute. Also, I've noticed when I add too much or maximum throttle, it also shuts off. Someone please help- I've bought this truck a few years ago and have only rode it for a maximum of 5 minutes.
#2
If the engine was new then, it's probably still new now and not broke in. It takes a little finesse to get an engine going and keep it going to get it broke in because the mixture settings are often way too rich and having to lean them down to keep the engine running. When the engine quits after you remove the glow driver, either your fuel mixture is too rich or the glow plug is no good regardless of what it looks like with the glow driver connected. See here for some info on reading your glow plug to determine how the engine is running and if the plug went south: http://www.rcuniverse.com/forum/rc-c...ght-wrong.html. (Read reply #5)
The element should be nice and round, shiny silver in color or have a slightly gray hazy appearance if it's good. Of course some plugs will look like this and not run the engine for beans. When in doubt, put in a new plug until the problems are sorted before "using up" any old used plugs. A bad glow plug will make you crazy when you don't know what to be looking for/doing with a picky engine.
Quitting on the high end - is it really boggy and smokey and revving slow then quitting or is it just flat out quitting? The former means it's too rich and needs to be leaned down; the latter means it's too lean. Of course having a good glow plug helps to remedy this as well because a bad glow plug will create other problems that may make you chase your tail.
The element should be nice and round, shiny silver in color or have a slightly gray hazy appearance if it's good. Of course some plugs will look like this and not run the engine for beans. When in doubt, put in a new plug until the problems are sorted before "using up" any old used plugs. A bad glow plug will make you crazy when you don't know what to be looking for/doing with a picky engine.
Quitting on the high end - is it really boggy and smokey and revving slow then quitting or is it just flat out quitting? The former means it's too rich and needs to be leaned down; the latter means it's too lean. Of course having a good glow plug helps to remedy this as well because a bad glow plug will create other problems that may make you chase your tail.
Last edited by 1QwkSport2.5r; 09-09-2015 at 07:07 PM.
#3
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Alright thanks, turns out it was the glow plug- now I'm breaking it in. I finished the first tank today by keeping it running in one place for a long time. The engine seems really loud (not sure if that's just my truck?) and for some reason, the longer it's running, the more the car has this one issue (maybe not an issue) that the wheels almost every 5 seconds begin moving to the front. Is this regular? Also- for the rest of the breaking in procedure, should I mess with the HSN or LSN at all? How many tanks more? Thanks.
#4
I never idle for break-in ever. I fire the engine up, drive it around to warm it up. If it's way rich and smokey and even boggy, I'll lean it down until it's running mostly clean and revving good but a little slow. Get the engine warmed up over 220F. I set my idle mixture as soon as it's warm to give a pretty snappy response but still rich and set my high speed mixture so it revs up and speeds up relatively quickly. If it revs out really fast, richen it down a little bit. The higher rpm breaks in the connecting rod which is the most crucial part of break-in. The piston/liner breaks in as it runs but to get the proper fits, it needs to be warm but not hot. Keep it under 260F for probably 6 tanks or so with a good cool-down between tanks and you should be fine to do the final tuning for power. Always keep it a bit rich. When tuning for power, set your high speed first (after the engine is warmed up). Run a WOT pass and lean it down and do another WOT pass. You're at peak setting when the engine sounds the same as the last pass and doesn't sound faster. If it revs up and speeds up and slows down a little and you hear the engine rpm drop while still WOT, you're too lean. Richen it back up 1/8 turn and you can move to the idle needle. Set the idle needle so the engine transitions from idle to WOT quick and cleanly. After you get what you think is the right setting, let the engine idle for 20 seconds and then lunch it to WOT. If it studders at all and takes a second to clean out and rev up, you're still a tad rich.
#5
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https://www.youtube.com/watch?v=z-GI90ZCAYQ would you say i could follow this procedure to break it in the rest of the tanks? The procedure starts about half way through.
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YET AGAIN, sorry for the multiple posts: I want to purchase an rc antenna tube on ebay. Would these fit my truck? http://www.ebay.com/itm/RC-Antenna-P...item4ad6d4ea24 . Also i lost one of my shock caps somehow so would this fit as well http://www.ebay.com/itm/ASSOCIATED-6...item43bdf7e50c .
#8
https://www.youtube.com/watch?v=z-GI90ZCAYQ would you say i could follow this procedure to break it in the rest of the tanks? The procedure starts about half way through.
#9
YET AGAIN, sorry for the multiple posts: I want to purchase an rc antenna tube on ebay. Would these fit my truck? http://www.ebay.com/itm/RC-Antenna-P...item4ad6d4ea24 . Also i lost one of my shock caps somehow so would this fit as well http://www.ebay.com/itm/ASSOCIATED-6...item43bdf7e50c .
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I assumed shock caps would be more expensive from RedCat, guess not. I was on my 4th tank today when my truck suddenly broke AGAIN. The engine, even when on high rpms, doesn't move the wheels (only minimally at near-full throttle, like crawling) unless the truck is lifted above the ground. When I shut the truck off there seems to be something spinning for about 3 seconds after the engine stops (I'm guessing it's the gears). The weird thing is, 10 minutes later- my friend got the SAME EXACT PROBLEM on his broken-in traxxas. What could this be? How to fix? Hoping it's not too expensive as this hobby is truly burning a hole in my wallet haha. Thanks.
#11
Could be a loose out drive yolk on the transmission, a loose slipper clutch, a broken drive shaft or pin inside the transmission, etc. Try holding the spur gear still and move the truck forward. If the truck moves and the spur gear doesn't, then it's something amiss between the spur gear and the wheels (slipper clutch or something in the transmission). The differential is worth looking in/at as well.
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The thing is, when the truck is moving forward, I can hold the spur gear (no pressure at all) and the truck still moves. When it goes backward however, the spur gear turns counter clockwise and I can't hold it (there is some odd grinding noise I've noticed here.)
I'll make these easier to read, as I go on rants.
A few things I've noticed are:
1.The spur gear wasn't originally touching the clutch unless it was slightly pushed down. Not sure if this was normal, but after I reinstalled everything, I must've put the engine a bit off so that they are in contact well now.
2. It is most likely not the slipper clutch, as I've loosened it and tightened it with no success.
3. When the transmission was out alone, I noticed that the two yokes spun when the spur gear was turning clockwise and counterclockwise, so I'm guessing it's nothing in the transmission? However, when turning clockwise- I believe I remembered that there was less pressure and I could have prevented the yokes from moving.
I'll make these easier to read, as I go on rants.
A few things I've noticed are:
1.The spur gear wasn't originally touching the clutch unless it was slightly pushed down. Not sure if this was normal, but after I reinstalled everything, I must've put the engine a bit off so that they are in contact well now.
2. It is most likely not the slipper clutch, as I've loosened it and tightened it with no success.
3. When the transmission was out alone, I noticed that the two yokes spun when the spur gear was turning clockwise and counterclockwise, so I'm guessing it's nothing in the transmission? However, when turning clockwise- I believe I remembered that there was less pressure and I could have prevented the yokes from moving.
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Extra info: the spur gear looks fine, and I read that the problem might be the clutch bell, clutch shoes, or friction pads. I doubt it's the clutch as I had bought a new one not a week ago. No clue if the friction pad is the problem, i feel like it's something bigger. What are your suggestions?
#14
Take the transmission apart. With no resistance, turning a spur gear will make the out drives turn unless you have a completely snapped shaft inside the transmission. A stripped gear will still function in low stress situations (like turning by hand). If you can hold the spur gear and move the truck without the spur moving, something is messed up inside the transmission. Never assume anything, or you'll never get anything fixed. Always try the simple things first, if that doesn't fix the problem, then go into more profound options.
I had a similar situation happen to me with a Jato 3.3 - the engine would just spin the spur gear but the truck wouldn't move. Turned out the input shaft of the transmission snapped in the middle where a drive pin went through to drive the 2nd gear hub. Pulling the transmission apart was the only way to diagnose and fix the problem. Plus this gives you insight of what's in the transmission so later if you encounter other problems, it will be easier to diagnose and repair it.
I had a similar situation happen to me with a Jato 3.3 - the engine would just spin the spur gear but the truck wouldn't move. Turned out the input shaft of the transmission snapped in the middle where a drive pin went through to drive the 2nd gear hub. Pulling the transmission apart was the only way to diagnose and fix the problem. Plus this gives you insight of what's in the transmission so later if you encounter other problems, it will be easier to diagnose and repair it.
Last edited by 1QwkSport2.5r; 09-15-2015 at 05:00 AM.
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The thing that got me was that the spur gear works counterclockwise, but not forward at all. And the clutch/gear mesh is heard ONLY when the truck goes backwards, but moving forwards it's silent. I'll try to disassemble the transmission later today.
#17
If the truck has a 2-speed transmission, there is likely a one-way clutch in the transmission that allows it to freewheel one way but drive the other. If the differential is in the transmission, open it up and make sure the gears are good and clean/not broken. If the truck is 4wd, then I'd ensure the driveshaft drive cups are tight. Basically what you need to do is go through the entire path the engines power takes to get to the wheels and make sure everything is right.
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Supposedely the differentials at the back of the car. I'll check the drive cups and diff tommorow. In case you're wondering, this is the transmission i have https://jet.com/product/product/2ae3...Z43BoCMxvw_wcB (i believe).
#19
Supposedely the differentials at the back of the car. I'll check the drive cups and diff tommorow. In case you're wondering, this is the transmission i have https://jet.com/product/product/2ae3...Z43BoCMxvw_wcB (i believe).