Idle

[Bristowfxnytro]

So I adjusted the Co this afternoon with negative results. Thinking I may have a dirty injector or throttle body. Going to run a bottle of Kleen-flo tko2000 through it with 93 octane in hopes this clears up. Plugs look good after a couple wot pulls. Thinking I might just have to deal with this. Bottom, mid and top end do not seem affected by this, and sled has lots of pull when easing into it. No codes on the dash so I’m at a complete loss with this. Definitely not as simple as a 2 stroke haha. Thanks for every bodies response!

 

[maim]

i think you have it narrowed down to it being in or on the throttle bodies. wonder if it could be the tps needing cleaning or adjustment as well?

 

[Hooray!]

Your video shows and sounds like the "normal" rough idle until it dies. I had to learn to start it and let it warm up totally or risk it choking out if gave it throttle early. I learned hard way once, especially at 0F and below, don't touch throttle, start it, let it catch, maybe give ever so slight throttle to keep thing at 1500ish rpms and then after a few min let it idle with no throttle and warm up 100% ( like 5+ min). Rush her and she will die and be a bitch to start. I respect that now and zero issues. Kind of reminds me of how your sounds so maybe mine is heading in your direction, I was thinking coils / electrical too... Don't think it is gas or air related...

 

[Primos003]

The only thing I would add is to go through all the ground blocks in the harness. Some have 4 points (wires), some have 6 and there are a bunch of them. Use a pick to pry the cap off, pull out the metal spider thing, clean it, and put some dielectric grease on them. Might not be the cause of your issue but its not difficult to do and it would eliminate one possibility.

The top plug with the black cap is an example of one. The ones with 4 wires are all black and in a straight line.

 

[Hooray!]

The only thing I would add is to go through all the ground blocks in the harness. Some have 4 points (wires), some have 6 and there are a bunch of them. Use a pick to pry the cap off, pull out the metal spider thing, clean it, and put some dielectric grease on them. Might not be the cause of your issue but its not difficult to do and it would eliminate one possibility.

The top plug with the black cap is an example of one. The ones with 4 wires are all black and in a straight line.

Great point, I went through each plug I could access, pulled apart and put dielectric grease on each, just the act of unplugging and pluging in helps avoid poor connections. The idle variability seems like a common trait. Does it die with throttle even when warmed up? There are some "rough idle" threads here, some old, I read most of them, all good info and maybe one is like your symptoms. There are some wear points to check where harnesses vibrate on engine casting nubs that has caused other electrical gremlins, seems like more common then we should see, but is what it is....

 

[Bristowfxnytro]

Great point, I went through each plug I could access, pulled apart and put dielectric grease on each, just the act of unplugging and pluging in helps avoid poor connections. The idle variability seems like a common trait. Does it die with throttle even when warmed up? There are some "rough idle" threads here, some old, I read most of them, all good info and maybe one is like your symptoms. There are some wear points to check where harnesses vibrate on engine casting nubs that has caused other electrical gremlins, seems like more common then we should see, but is what it is....

yeah it still dies when warmed up when I blip the throttle a few times when coming to a roadway or from a dead stop. Have no codes and recently tested tors to make sure it wasn’t part of the problem. I’ve checked tps setting 16 at idle and 95 wot. New plugs. I’m thinking about taking the air box off tomorrow and taking a gander at the throttle bodies. Anything I should look for when inspecting? Going to purchase some throttle body cleaner, as well as injector cleaner.


Is there a way to drain the fuel tank without removing it completely? Perhaps unhooking fuel line and turning the sled to “on” to engage fuel pump?

 

[Big_Phil]

yeah it still dies when warmed up when I blip the throttle a few times when coming to a roadway or from a dead stop. Have no codes and recently tested tors to make sure it wasn’t part of the problem. I’ve checked tps setting 16 at idle and 95 wot. New plugs. I’m thinking about taking the air box off tomorrow and taking a gander at the throttle bodies. Anything I should look for when inspecting? Going to purchase some throttle body cleaner, as well as injector cleaner.


Is there a way to drain the fuel tank without removing it completely? Perhaps unhooking fuel line and turning the sled to “on” to engage fuel pump?

Good luck with this problem. My buddy bought a Nytro last year that does the exact same thing. We swapped everything pretty much. Throttle bodies. Coils. Ecus, you name it. We are going to try a new wiring harness this year, or my only other thought is the bearing on the stub shaft might be shot and dragging the engine down at idle. Its pretty baffling actually. I will post here if we get it figured out. The sled does the exact same thing yours does.

 

[Alexandre Cote]

What color are your plugs, could be dumb as a bad ECT that makes it run to rich. As someone mentioned checking exhaust temps is a good idea if one cylinder is not firing properly.

How many miles does the sled have ? If it's high miles the valves could need adjustement, my wife's rs rage is a high miles sled and add a idle problem that I trace to tight valves !