What did you do to your TJ today?

Took the Jeep on a trash mission. Winched ~40 tires up back to the road, two safes, a dishwasher a few more sundry items...used a stick to get to 1500 rpm for better winching voltage on long pulls...

001 - Safe Being Winched Up.png
002 - Shoving Stick Under Throttle to Enable High Idle Mode.png
003 - Tug of War.png
004 - Tires.png
005 - Minding the Winch Rope.png
006 - Tires Up.png
 
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macleanflood said:
Took the Jeep on a trash mission. Winched ~40 tires up back to the road, two safes, a dishwasher a few more sundry items...used a stick to get to 1500 rpm for better winching voltage on long pulls...

View attachment 672297View attachment 672298View attachment 672299View attachment 672300View attachment 672301View attachment 672302
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You gotta get yourself one of these:
https://genright.com/shop-by-vehicl...A1fAEBRHv77V_ZhfztA4cu-PnWA0sT41-HVHYvSTSH7dH


It's mostly designed for manuals but can help for other sustained throttle uses
 
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andyj said:
I went 4WDing to 4WD Park Adelaide yesterday. And got stuck on a steep incline because I ran out of clearance and stalled the engine. I decided to slowly roll back and as soon as I took my foot of the break the TJ rolled back. It was steep enough to roll back with first low still engaged. That let the engine start up immediately and I rolled down safely. That engine was running in reverse! I could hear it clearly, the timing chain made very unusual noises. I stopped that as soon as I came to a halt and switched it off. When I restarted the engine, it ran just fine. Only the vacuum hose popped off, noticeable by some loud hissing. Popped it back on and all was good.

I had no idea that this would even be possible!
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It's not possible.

You can turn the engine backward, and it will pump air backward. But aside from some old steam engines, it won't run backward. It would suck air in from the exhaust, and compress it, but the PCM wouldn't get the right signals to control the spark and fuel injection. And even if it did, depending on how it timed things, the fuel would be injected into the port above the closed intake valve, or into the air flowing out into the intake manifold. Keep the engine turning backward, and it will pump the air out through the intake manifold, throttle body, and air intake. And it will blow off vacuum hoses, and possibly damage sensors and brake boosters. It will make funny huffing, chuffing noises, but it sure isn't going to "run".
 
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OldBuzzard said:
It's not possible.

You can turn the engine backward, and it will pump air backward. But aside from some old steam engines, it won't run backward. It would suck air in from the exhaust, and compress it, but the PCM wouldn't get the right signals to control the spark and fuel injection. And even if it did, depending on how it timed things, the fuel would be injected into the port above the closed intake valve, or into the air flowing out into the intake manifold. Keep the engine turning backward, and it will pump the air out through the intake manifold, throttle body, and air intake. And it will blow off vacuum hoses, and possibly damage sensors and brake boosters. It will make funny huffing, chuffing noises, but it sure isn't going to "run".
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Maybe. But mine kept running backwards until I switched it off. That's all I can say.
 
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I'm always paranoid of my ignition actuator breaking on the trail so I carry a spare with me. I thought it would be a good idea to go through the motions of replacing it to make sure I am carrying the proper tools and could do it trailside. To my surprise, I found this. The jeep was still starting fine but I guess it was only a matter of time.

IMG_4040.jpeg
 
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andyj said:
I went 4WDing to 4WD Park Adelaide yesterday. And got stuck on a steep incline because I ran out of clearance and stalled the engine. I decided to slowly roll back and as soon as I took my foot of the break the TJ rolled back. It was steep enough to roll back with first low still engaged. That let the engine start up immediately and I rolled down safely. That engine was running in reverse! I could hear it clearly, the timing chain made very unusual noises. I stopped that as soon as I came to a halt and switched it off. When I restarted the engine, it ran just fine. Only the vacuum hose popped off, noticeable by some loud hissing. Popped it back on and all was good.

I had no idea that this would even be possible!
Click to expand...

Could Be Worse Let It Go GIF
 
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OldBuzzard said:
It's not possible.

You can turn the engine backward, and it will pump air backward. But aside from some old steam engines, it won't run backward. It would suck air in from the exhaust, and compress it, but the PCM wouldn't get the right signals to control the spark and fuel injection. And even if it did, depending on how it timed things, the fuel would be injected into the port above the closed intake valve, or into the air flowing out into the intake manifold. Keep the engine turning backward, and it will pump the air out through the intake manifold, throttle body, and air intake. And it will blow off vacuum hoses, and possibly damage sensors and brake boosters. It will make funny huffing, chuffing noises, but it sure isn't going to "run".
Click to expand...

Many diesels will run backwards as well. Old marine diesels were actually run backwards to go backwards. They had to stop the engine, and recrank in reverse - often by hand (these were primitive one lungers).
 
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Zorba said:
Many diesels will run backwards as well. Old marine diesels were actually run backwards to go backwards. They had to stop the engine, and recrank in reverse - often by hand (these were primitive one lungers).
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The only engines I've seen capable of running backwards were 2 stroke , gas and diesel . Yamaha golf cart and 3-71 Detroit Diesel in a Gama- Goat.
 
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ColoJeep said:
The only engines I've seen capable of running backwards were 2 stoke , gas and diesel . Yamaha golf cart and 3-71 Detroit Diesel in a Gama- Goat.
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The Polaris and Ski-Doo two stroke snowmobile engines still do that. Rather than a reverse gear assembly, there’s a switch on the handlebar you press with the engine idling. It kills the ignition, and the ECU monitors the engine RPM. Just before it stops spinning, ignition is started again with altered timing, and the engine runs backwards. Another press of the button, and the same thing happens to restart the engine running forwards.

Ski-doo had a patent on the technology, but Polaris traded another patent with them, so they both have the technology.
 
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sab said:
The Polaris and Ski-Doo two stroke snowmobile engines still do that. Rather than a reverse gear assembly, there’s a switch on the handlebar you press with the engine idling. It kills the ignition, and the ECU monitors the engine RPM. Just before it stops spinning, ignition is started again with altered timing, and the engine runs backwards. Another press of the button, and the same thing happens to restart the engine running forwards.

Ski-doo had a patent on the technology, but Polaris traded another patent with them, so they both have the technology.
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That's really cool. It's crazy what some people can come up with and design and it all works.
 
speeding_infraction said:
That's really cool. It's crazy what some people can come up with and design and it all works.
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Yeah, mountain sled owners are very weight-conscious. They'd rather have no reverse gear than take the weight penalty to add a reverse gear assembly. I don't recall the exact sequence of events because it occurred prior to my employment at Polaris, but I know that being able to add reverse with almost no weight penalty was very important to Polaris, which is why they traded patents with BRP (Ski-doo). Because there's no valve train on those two-stroke engines, it was a pretty easy engineering project once electronic ignition was available.
 
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sab said:
Yeah, mountain sled owners are very weight-conscious. They'd rather have no reverse gear than take the weight penalty to add a reverse gear assembly. I don't recall the exact sequence of events because it occurred prior to my employment at Polaris, but I know that being able to add reverse with almost no weight penalty was very important to Polaris, which is why they traded patents with BRP (Ski-doo). Because there's no valve train on those two-stroke engines, it was a pretty easy engineering project once electronic ignition was available.
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Arctic Cat did the same thing on the 2009 Crossfire 800 , you pushed a button on the handlebars at idle and when the piston was near TDC it fired the spark way early forcing the piston down , reversing the engine rotation. Fun 2-stroke trick !
 
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