5.9 acceleration problems

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MrBreazeal

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Ram Year
1996
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V8 5.9
So I've got a 94 1500 with the 5.9 at 151k miles....never had a problem until now, when i get to a steady speed, no matter what mph I'm going, the rpm always drops to 1500 and if I step into it gradually, it's very laggy and slow to speed up then if I dump the throttle, it doesn't change or speed up for a good couple seconds then out of nowhere shifts twice back to back and takes off. I've already replaced the tps twice with no change and no code is thrown. Anything else that could be causing this?
Thanks for all the help in advance!
 

dudeman2009

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2001 1500 Sport with enough electrical modifications to make my brain hurt
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Magnum 360
I would start by checking the throttle cable that runs from the throttle body to the trans throttle position lever. You can always check the fluid level and color.
 

SportRam00

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The factory service manual has the proper adjustment procedure for this cable. There is a link to download it in the DIY section. Usually only a very small adjustment is needed. Too tight and the truck will kick down early. Too loose and it will kick down later. Finding the sweet spot can be tricky.
 

dapepper9

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5.9L V8
Are you familiar with the term overdrive? Overdrive is your 4th gear and is supposed to do that once you get up to around 40-45mph+. That lack of response when mashing the throttle is because these use a lockup tq converter and it locks up in overdrive or cruising above 55 when in 3rd.

I don't think anything is wrong. However, if you press that O/D off button when you're trying to accelerate, I think you'll be pleasantly surprised by how it reacts.
 

Yeret

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I'm inclined to agree with pepper here. You mean to say the Rs drop to 1,500 the same if you're doing 60 vs 80?

Overdrive is a HUGE bog on our trucks. I've got a tune and even with it there's a very long and steep hill that I only encounter every once in a great while and even if I hit it doing 70, I'll end up only doing 50 when I finally crest it. If I kick off the overdrive however I can cruise up it doing 70 with less throttle input.
 
OP
OP
M

MrBreazeal

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I'll look into the cable thread, also I don't think it's a normal overdrive issue because I've had this truck for 2 years and it just recently started doing this, it's not just highway speeds either...I can be doing 30 mph and once I get a steady speed, the rpm drops from example... 2300 down to 1500 and stay there even if I gradually speed up but the truck will speed up very slowly while the rpm still sits at 1500 unless I step into it then the lag occurs until it takes off and shifts twice.

Thanks for all the replies!
 

dudeman2009

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2001 1500 Sport with enough electrical modifications to make my brain hurt
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Magnum 360
I'll look into the cable thread, also I don't think it's a normal overdrive issue because I've had this truck for 2 years and it just recently started doing this, it's not just highway speeds either...I can be doing 30 mph and once I get a steady speed, the rpm drops from example... 2300 down to 1500 and stay there even if I gradually speed up but the truck will speed up very slowly while the rpm still sits at 1500 unless I step into it then the lag occurs until it takes off and shifts twice.

Thanks for all the replies!

Mine does that same thing, thats you overdrive. Its not suposed to engage until 40+mph, but ive found mine will engage all the way down near 35. I'm guessing its engine rpm based not speed based, and the nominal rpm for the **** just happens to be around 40mph.

You can still check the throttle cable, it won't do any harm. If you're convinced something is wrong, you can change the trans filter and fluid.
 

Jimmy68

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So what your saying is at 30 mph at 1500 RPM you can speed up to 80 MPH slowly and your RPM never changes?
 

dudeman2009

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So what your saying is at 30 mph at 1500 RPM you can speed up to 80 MPH slowly and your RPM never changes?

I've got a bad trans, it need a rebuild. When mine goes at about 35 my rpms drop to a crushing 1000rpm. Kick off OD and it jumps to 1300rpm with TC lockup.

OP sounds like he is in 3rd at 30mph with the TC still open. It makes sense that flooring it causes two downshifts as that would take it to first. You hit 30mph in first at about 3000rpm. So that wouldn't be a stretch at all for WOT.
 
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