Power/Acceleration issues (1 Viewer)

[wickerman]

First a disclaimer, I know very little about transfer cases.

Last week the weather here was pretty bad so I had my '80 fj40 in 4hi to get to and from work (about 2 miles round trip). Everything was running great with the exception of a minor short in the ignition harness plug that's fixed with a little wiggling when it's acting up. I left town for the weekend and my wife was driving the truck and when I get back, it's no longer accelerating. Top speed is about 20 mph and it takes about 1/4 mile to get there. It feels like the transfer case is out of gear, but I know it's "in" according to the shifter. I've got it back in 2 and unlocked and it's ridiculously sluggish.

Any ideas?

 

[John Smith]

Are you sure you are not in low range? It sure sounds like you are. The transfercase shifter linkage has been known to freeze up and or get sloppy over the years.

 

[Degnol]

I'd check and replace the fuel filter. I had a Yukon that would not go 70mph because of fuel starvation.

Just a guess.

Ed

 

[wickerman]

John Smith, About the tcase sticking, that's certainly what it feels like, but the shifter feels like it's going all the way into gear. Any good way to verify that without putting the car up on blocks and hitting the gas?

As for the fuel line issue, I had thought it might be an issue, but the engine seems to be running fine in idle and when I give it gas, it just feels like the power isn't hitting the wheels.

 

[John Smith]

Have someone move the transfer case shifter while you watch the shifter on the top of the transfercase. If you don't have a helper, undo the linkage and manually shift the upper transfercase between low, neutral, and high, then get in and drive it and see if anything changes. If my memory serves me... low is towards the back and high is towards the front.

 

[Felix]

If my memory serves me... low is towards the back and high is towards the front.

Is the '79-'83 different than the '74-'78? In mine up/down is 2wd/4wd; left/right is high/low.

 

[wickerman]

Is the '79-'83 different than the '74-'78? In mine up/down is 2wd/4wd; left/right is high/low.

That's how mine is set up.

 

[John Smith]

I had to modify my shifter for my toybox, mine was the same as both yours.

 

[wickerman]

Finally got a chance to tinker with it last night. It looks like the transfer case is engaging correctly. I adjusted the idle a bit to see if that made a difference and the engine is running "correctly" just not well. I do think I figured it out though. On Friday I just about lost my muffler, but I wired it back on temporarily until I could get a replacement. I think that something may have gotten screwed up and is impeding flow.

Just curious, does anyone know if the MAF bolt on muffler will replace the stock muffler at the triangle flange? I've got an email into them, but I haven't heard back yet.

 

[wickerman]

Problem Solved

At some point something inside the muffler had broken loose and was blocking the exhaust. I replaced the muffler and it's working find now. I'm just glad it was something simple!

Thanks for the help guys!