Slow acceleration - JeepForum.com
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post #1 of 15 Old 09-18-2016, 02:43 PM Thread Starter
xlTravislx
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1994 YJ Wrangler 
 
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Slow acceleration

Whats the worst combination for bad acceleration?
Start off with a 2.5L engine with 250k on the odo.
Then add the 3 speed Automatic (30RH)
In addition will be 3.73 highway gears.
Top it off with 33x12.50 M/T and a jeep with surrounded with armor.

So thats what I'm working with..

However I recently had some connections on my ECU "re-connected" I found out that I have an overdrive in 3rd gear! It almost feels like a 4th gear. This is great! But..

My issue is I have what feels like no power from 2,000rpm up to about 3,000. This means accelerating through every gear, even cursing at 50mph I have to put my pedal to the floor just to move.

Before this issue occurred I had pretty decent acceleration, and could rev through my 3 gears very quickly. Now anytime I move I have to put the pedal to the floor.

Any common causes or culprits to this issue?

*pic for entertainment.


-White Jeep Club Member 231-
Replacing random parts on hunches spurred from other vehicles and peoples experiences with them is the safest bet.
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post #2 of 15 Old 09-18-2016, 03:54 PM
Drednot
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Yes. you have the most gawd-awful combination of any YJ.

What "connection" did you fix?

I'm wondering if you somehow activated a TCC (Torque Converter Clutch) and its now locking up at the wrong time? It will act like an "overdrive" but will kill any torque multiplication in the converter.
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post #3 of 15 Old 09-18-2016, 03:59 PM Thread Starter
xlTravislx
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Quote:
Originally Posted by Drednot View Post
Yes. you have the most gawd-awful combination of any YJ.

What "connection" did you fix?

I'm wondering if you somehow activated a TCC (Torque Converter Clutch) and its now locking up at the wrong time? It will act like an "overdrive" but will kill any torque multiplication in the converter.
Thanks for the refreshing words about my jeep haha! (no harm!)
The "connection" they fixed was my 5v power to my TPS and MAP sensor.

The mechanic must have done something electronically to engage this (what feels like) overdrive. However It came at the expense of no torque.

I have very good throttle response and I can rev high with no issues in Park/ Neutral.

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post #4 of 15 Old 09-18-2016, 04:28 PM
Chrisnvegas
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It's not an overdrive, the torque converter locks up now, eliminating slip, and torque.

I had one on my CJ in Colorado.
Yanked that sucka. It wasn't worth the 200 rpm savings. Had to almost floor it to get it to unlock, then it would usually downshift to second.
So I disconnected it.

Not all Jeeps have them. My 1992 somehow dodged the lockup torque converter bullet and I'm ok with it.

I have heard people who add a disconnect switch where you can turn it off if you need to and turn it on if the road is level and you want to save fuel.

Lockup torque converter + and -

1. Eliminates slippage so trans oil runs cooler when engaged.
2. Saves fuel by providing a direct connection to wheels.
3. Lowers RPM by a couple hundred.

Me?

Have a big trans cooler so I don't care about slippage and heat
Don't care about fuel mileage.
Don't care about the measly couple hundred RPM

I want power available all the time.
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post #5 of 15 Old 09-18-2016, 06:17 PM Thread Starter
xlTravislx
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Quote:
Originally Posted by Chrisnvegas View Post
It's not an overdrive, the torque converter locks up now, eliminating slip, and torque.

I had one on my CJ in Colorado.
Yanked that sucka. It wasn't worth the 200 rpm savings. Had to almost floor it to get it to unlock, then it would usually downshift to second.
So I disconnected it.

Not all Jeeps have them. My 1992 somehow dodged the lockup torque converter bullet and I'm ok with it.

I have heard people who add a disconnect switch where you can turn it off if you need to and turn it on if the road is level and you want to save fuel.

Lockup torque converter + and -

1. Eliminates slippage so trans oil runs cooler when engaged.
2. Saves fuel by providing a direct connection to wheels.
3. Lowers RPM by a couple hundred.

Me?

Have a big trans cooler so I don't care about slippage and heat
Don't care about fuel mileage.
Don't care about the measly couple hundred RPM

I want power available all the time.
Thank you for this info! its very helpful! I spoke to someone earlier today who knows the electronics on our YJ's very well. He said that there is only one wire which controls or communicates to the ECU for my jeeps auto trans. The guy who fixed my 5v supply into my ECU also fixed a mystery wire that was also loose. This HAD to have been the reason why my T.C is locking up. Now that the wire is getting connection, its technically "fixed" in a since.

It sure is nice letting the engine run smother and saving gas but I really want POWER like I used to have..
Currently Im a old dog who can't even get out of my own way. Of anything its a safety hazard having no throttle. driving around with the pedal to the floor and no acceleration.

Have you seen any wright ups on the disconnect? I have a good idea of how to do it with a switch in the cab that can cut power to the wire going into the ecu that controls the T.C. It seems pretty straight forward once I figure out which wire it was exactly.

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post #6 of 15 Old 09-18-2016, 06:40 PM
Chrisnvegas
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Look for the wire on the trans.
It should be separate from the neutral and reverse light wire (plug)

I'm pretty sure it is a single wire and a round plug just above the pan toward the front but on the drivers side. (I think)
You should be able to put in a dash switch to interrupt.
It receives 12v+
I'm not sure how much amperage. It's a thin wire so I don't think it takes much.

I'm going by memory from my CJ days.
That was before I went senile.

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post #7 of 15 Old 09-18-2016, 07:59 PM Thread Starter
xlTravislx
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Quote:
Originally Posted by Chrisnvegas View Post
Look for the wire on the trans.
It should be separate from the neutral and reverse light wire (plug)

I'm pretty sure it is a single wire and a round plug just above the pan toward the front but on the drivers side. (I think)
You should be able to put in a dash switch to interrupt.
It receives 12v+
I'm not sure how much amperage. It's a thin wire so I don't think it takes much.

I'm going by memory from my CJ days.
That was before I went senile.
Well I really appreciate your senile help!

Do you have any idea if the wire is removable or does it go to a connector inside the transmission that can't be accessed from the outside of the trans.

Im not around my jeep right now or else Id go look for it and post up some pics to ensure I got the right wire.

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post #8 of 15 Old 09-18-2016, 08:20 PM
Chrisnvegas
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The connector can be removed from the outside.
It plugs into the side of the trans.

Then inside the pan it goes to the solenoid in the valve body that operates the lockup.

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post #9 of 15 Old 09-18-2016, 08:31 PM
Chrisnvegas
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If you don't already have an external trans cooler, your trans would really appreciate it if you installed one.
I also really want you to change your trans oil a few times. ATF +4 ()

Here's an easy way to do it.

Pick up one of these. It will pay for itself fast.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

You can put the tube down the trans dipstick and in a minute or less, suck the old trans oil out without even getting dirty.
You will need to do it a few times over a month or so because it sucks about half out.
The other half is in the torque converter.

Your trans oil will be clean and cool if you do ^^^^

Keeping the trans oil cool and clean will WAY increase the service life and save you big money in the long run.
Spend a little now, or spend big bucks later...

I have this trans cooler
Made in Australia.

https://www.amazon.com/Hayden-Automo.../dp/B000C3BBKS
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post #10 of 15 Old 09-19-2016, 06:08 PM Thread Starter
xlTravislx
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Join Date: Aug 2010
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Posts: 613
Quote:
Originally Posted by Chrisnvegas View Post
If you don't already have an external trans cooler, your trans would really appreciate it if you installed one.
I also really want you to change your trans oil a few times. ATF +4 ()

Here's an easy way to do it.

Pick up one of these. It will pay for itself fast.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

You can put the tube down the trans dipstick and in a minute or less, suck the old trans oil out without even getting dirty.
You will need to do it a few times over a month or so because it sucks about half out.
The other half is in the torque converter.

Your trans oil will be clean and cool if you do ^^^^

Keeping the trans oil cool and clean will WAY increase the service life and save you big money in the long run.
Spend a little now, or spend big bucks later...

I have this trans cooler
Made in Australia.

https://www.amazon.com/Hayden-Automo.../dp/B000C3BBKS
Im pretty sure I already have an external Trans cooler. It looks very similar to the link you posted of yours. Ive never had any issues with it so I never looked into it.. Here is a picture of it

Im not sure If I mentioned it earlier but I have a rebuilt transmission as of about 6 months ago. Its got a 2 year warranty. I got my jeep with 110k on the odo 6 years ago.. shortly after purchasing my speedo went out. (thats a whole nother issue that I don't want to get into, I don't mind no speedo) The trans just recently went out and I NEVER had this locked up torque convertor issue.

Im pretty good about maintenance on my jeep. The ATF+4 is pretty pink/red and properly filled. Cheeked as of a couple days ago.

I did find the single wire that plugs into the drivers side of the transmission. I first thought it was a vacuum line because of the 90 degree rubber black connector. I unplugged it and went down the street. Immeaditly had my power back.. But Im going to miss that "4th gear" on the highway.

I did some research and found that the wire travels up to the ECU which only gives a ground signal. The solenoid itself gets its +12v power from somewhere in the fuse box I think..? Anywho..

If I were to splice in a switch Im assuming I would cut this wire and redirect it (with more wire) to the in cab toggle switch positive terminal (maybe ground terminal?) Then run another wire from the switch to the 90 degree connector which would be plugged into the trans.


Like I mentioned before electronics are not my favorite. Far from it actually. But Im trying to learn.

I want a toggle because Im selfish and I want the best of both worlds. #power #4thGear

-White Jeep Club Member 231-
Replacing random parts on hunches spurred from other vehicles and peoples experiences with them is the safest bet.
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post #11 of 15 Old 09-19-2016, 07:12 PM
Chrisnvegas
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Quote:
Originally Posted by xlTravislx View Post
Im pretty sure I already have an external Trans cooler. It looks very similar to the link you posted of yours. Ive never had any issues with it so I never looked into it.. Here is a picture of it

Im not sure If I mentioned it earlier but I have a rebuilt transmission as of about 6 months ago. Its got a 2 year warranty. I got my jeep with 110k on the odo 6 years ago.. shortly after purchasing my speedo went out. (thats a whole nother issue that I don't want to get into, I don't mind no speedo) The trans just recently went out and I NEVER had this locked up torque convertor issue.

Im pretty good about maintenance on my jeep. The ATF+4 is pretty pink/red and properly filled. Cheeked as of a couple days ago.

I did find the single wire that plugs into the drivers side of the transmission. I first thought it was a vacuum line because of the 90 degree rubber black connector. I unplugged it and went down the street. Immeaditly had my power back.. But Im going to miss that "4th gear" on the highway.

I did some research and found that the wire travels up to the ECU which only gives a ground signal. The solenoid itself gets its +12v power from somewhere in the fuse box I think..? Anywho..

If I were to splice in a switch Im assuming I would cut this wire and redirect it (with more wire) to the in cab toggle switch positive terminal (maybe ground terminal?) Then run another wire from the switch to the 90 degree connector which would be plugged into the trans.
Like I mentioned before electronics are not my favorite. Far from it actually. But Im trying to learn.

I want a toggle because Im selfish and I want the best of both worlds. #power #4thGear
Don't add 12v +
Allow the computer to decide when the lock up is needed.
Add a toggle to interrupt the signal when you don't want the lockup engaged.

Take the one wire to the trans. Cut it 6" back to give yourself room to splice.
Take the section of wire from the computer and add enough wire to reach your toggle switch. Connect to the toggle switch.

From the toggle switch (the other terminal on the switch) connect a wire and run back to the trans
Connect that wire to the wire that goes into the trans.
Done.
The toggle switch will interrupt the signal when the switch is off.
Turn the switch on, the computer will engage the lockup at speed.

Run the wire in split loom tubing like this to protect the insulation from rubbing and shorts. Doesn't have to be this exact tubing, it's just an example.
http://www.oreillyauto.com/site/c/de...0213&ppt=C0335

When running the wire, keep away from sharp spots, things that move (steering components ect) things that get hot (like the exhaust)

Attach the wire every foot or so to something sturdy under the Jeep.
If you drive where there is ice, it will form under the jeep, cling to the wire and pull down. Ice can get heavy.

For use under the Jeep exposed to salt and water, I recommend waterproof wire connectors.
Wires under the Jeep are subject to chemicals and corrosion.
The connection WILL fail eventually.

Unless you seal your connections.
This is what I use.
Liquid electrical tape, brush on.

https://www.amazon.com/Star-brite-Li.../dp/B00U2JALTE

It will seal your connections from water and chemicals so they will never corrode.
Great for trailer wiring too.

My Jeep is NOT a Fiat!
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post #12 of 15 Old 09-20-2016, 01:35 PM
bruinjeeper
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you had my setup when i got mine and the previous owner had 33" pizza cutters on it. (TSL Swampers)

I sold those and picked up 31s... was VERY good (for what it is). THen found a d44 rear and d30 front...4.11/4.10 respectively... swapped those in... moved up to 33x12.5's and its bearable. Pretty good, not ideal... but i have no trouble accelerating fairly quickly.

You may want to regear or find suitable axles with better gear ratio and swap them in (the latter being easiest imho)

Stop whining about the 'ride' - If your YJ ain't wrangling your soul free, then might I suggest you buy a stationwagon... at least you can fit all your bull**** in the back.
~YJOTM MAY '16~
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post #13 of 15 Old 09-20-2016, 01:36 PM
bruinjeeper
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...curious... do you have shims on your front axle/springs?

Seems like an odd angle for your shackles to be in when parked on a flat surface

Stop whining about the 'ride' - If your YJ ain't wrangling your soul free, then might I suggest you buy a stationwagon... at least you can fit all your bull**** in the back.
~YJOTM MAY '16~
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post #14 of 15 Old 09-20-2016, 03:53 PM
mike134
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Quote:
Originally Posted by bruinjeeper View Post
...curious... do you have shims on your front axle/springs?

Seems like an odd angle for your shackles to be in when parked on a flat surface
How can you tell? that's so much shackle!
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post #15 of 15 Old 09-20-2016, 04:10 PM
bruinjeeper
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despite that, it definitely seems like his axle is rotated forward.

i dont know what to say about the turtlecon except inquire: did you make this thing yourself? do you know if shims are there or not? Those shackles are leaning in the wrong direction of my comfort

Stop whining about the 'ride' - If your YJ ain't wrangling your soul free, then might I suggest you buy a stationwagon... at least you can fit all your bull**** in the back.
~YJOTM MAY '16~
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