4th gear has no power up hill

[Sk8rmike85]

(2.9 engine 5speed manual) on a steep hill my truck will accelerate well in 1st 2nd & 3rd but when i put in 4th it starts to slow down and sputter a little bit, any ideas or quick fixes would be appreciated

 

[JayTee]

Try shifting it back into 3rd.

 

[ab_slack]

It is only a 2.9L.

I have a long steep hill around here. I can get up in it in 4th...5th maybe but not so good, but to accelerate, have some power reserve, I drop to 3rd. This is on a 55mph highway.

On a particularly steep hill near me, 3rd I can hardly maintain and need to drop to second. The sped limit is only 30mph so zero chance of everusing 4th gear.

 

[RonD]

Could be fuel filter is getting a little clogged, can't pass fuel fast enough for high demand.
maybe even fuel pump(s).
I would replace fuel filter just because........
Might need to rent a fuel pressure tester for the pumps.

If you have an EGR system it might be opening too much at lower RPMs under load

 

[Sk8rmike85]

the only thing that scares me a little is that i dont have a Tachometer, so i dont like to drop it into 3rd, my truck just sounds like its red lining hella hard. but i will try all your suggestions including changing the fuel filter. thank you for your information fellas

 

[adsm08]

You can do 55 in 3rd gear with a 2.9 for short stretches like climbing a steep hill and not do any damage.

Around here in the winter I will sometimes hold her at 55 in 3rd just to get the heat moving faster. With 3.73 gear and 29' tires that works out to about 3K. The 2.9 should be able to handle extended operation at that speed. Unless you let it get low on oil or something. Red line on the factory 2.9 tach was about 6K.


For an idea of what your engine is trying to work with, go borrow someone's 10 speed bike and ride up that hill. First do it with the bike in 3rd gear. Then find the setting that has the front and rear cogs that are closest in size and go again. That would be the bike's "direct drive" gear, which is numerically the same as your 4th gear.

 

[Mark_88]

My 2.3 has seen high rpms most of its life...I usually wind it out as much as possible, but I have found recently that due to my larger tires my speedo is off by at least 10 km/hr (lower than it should be)...so I've been pushing the little guy deeper, I mean my engine, than it probably should be pushed at his age.

 

[bmerr98]

You can also look at the tire and gear chart in the tech info section, I believe it's in the axle section. You can look up what performance profile you're working with according to tire size and gear ratio. For example I run 31 inch tires and 3.73 gears. That puts me in the "best overall performance" profile closer to the better MPG range. Perfect for what I need, but maybe not what a hard core off road type would want.

And, as previously mentioned, engines only put out so much, and gravity being what it is you just need a lower gear sometimes. Definitely do the fuel and air filters though. Never hurts and often overlooked.

 

[JayTee]

the only thing that scares me a little is that i dont have a Tachometer, so i dont like to drop it into 3rd, my truck just sounds like its red lining hella hard. but i will try all your suggestions including changing the fuel filter. thank you for your information fellas

Put a tachometer in it. Another quick cheap solution to your problems.

Welcome.

 

[JayTee]

My 2.3 has seen high rpms most of its life...I usually wind it out as much as possible, but I have found recently that due to my larger tires my speedo is off by at least 10 km/hr (lower than it should be)...so I've been pushing the little guy deeper, I mean my engine, than it probably should be pushed at his age.

What's the mileage on it?

I've got 300,000km on mine and it runs very well. I wind the piss out of it all the time- you have to. It doesn't make any power otherwise even when new.

 

[Scrambler82]

Get some 4.10 gears and replace the 3.73s.

Around town driving will be easier and on-highway will feel like the truck has what it needs for hills, you might even get in 5th.

 

[Mark_88]

What's the mileage on it?

I've got 300,000km on mine and it runs very well. I wind the piss out of it all the time- you have to. It doesn't make any power otherwise even when new.

The block was replaced about 60,000 km ago and the head about 10,000 km ago...originally made pretty good power...where it would make it up hills without having to down shift...now...well, not so much power as noise...

 

[adsm08]

I rechecked my math today on the way to work. 3rd at 55 is more like 3500 to 3600.

 

[Road Angels]

power

Was she an oil burner before you changed out the engine, exhaust system may be getting carboned up, also low tire pressure makes for a lot of drag and power loss, my 2.3 86 pulls big long hills in 4th no problem in 55 mph zones it just needs a head start at 75 mph

 

[snake]

Check compression, check cats for clogging.