Jeep doesn't move when I step on gas...
 

Over the last week or so, there have been maybe three times when, while being at a full stop and then step on the gas, the Jeep doesn't go anywhere. Twice it was in forward and once in reverse. If I let up on the gas and press the accelerator again all is normal. It was like I had my foot on the brake at the same time as the accelerator - or - that the tires where butted up to something, but that wasn't the case. This phenomenon only happens maybe 3 out of 10 trips out.

They only other thing I can think of is at one point I had the emergency brake on and drove about 10 feet or so in reverse.

Any ideas appreciated.

Could it be the fuel filter ? When I mentioned it to my wife today she said - when I went over a tall speed bump the other day the Jeep seemed to hesitate.

test your TPS (throttle position sensor), I had a similar issue on another vehicle.
https://troubleshootmyvehicle.com/je...sensor-tests-1

Thanks - I will certainly mention that to our mechanic when I see him on Monday to install new shocks.

Only trouble with your thought is that the only code thrown by the car's computer is PO456 (small evap leak).

Many times the tps won't throw a code. On my other vehicle it didn't. If you have a Bluetooth dongle and torque (and torque scan) or a scan tool you should see the voltage the jeep ecm is seeing when you go from closed throttle to wot. See if the voltage is changing when you play with the throttle (from .low voltage to like 4 volts at wot)

Could be a vacuum line cracked or came loose.

If you haven't put a new fuel filter on in a while you aught to just go ahead and do so simply for maintenance reasons.

The car is in the shop at the moment getting new shocks. We will pick it up in the morning.

A 2001 Jeep Cherokee Sport apparently does not have a serviceable fuel filter...

I checked the computer for any error codes thrown and only saw our 'small evap leak' issue.

The mechanic has driven the car today and noticed the same 'hesitation' as we did. He is not sure what it is - but he said he needs to check the transmission to see what if any codes it has thrown. That is the first I am every hearing about that ! He also mentioned that the transmission has a series of solenoids associated with it and perhaps on of those is acting up.

Does that make any sense ?

Don't stress -- you're extremely unlikely to need the sort of transmission work that costs a ton of money. The solenoids are a common failure point and there are several threads - it seems folks have had good luck with the ebay cheapo stuff for replacement.

I'd start a new thread with the title something along the lines of "01 XJ throwing code [insert code here] 'small evap leak' - please advise" -- I'm sure someone has had and fixed that issue and may have the same hesitation symptom. You can research the shift solenoids - it sounds like the mechanic is going in the right direction. It certainly is a very reasonable hypothesis.

I had the same issue a while ago
 

In my case it got progressively worse until it would not go into reverse and the forward gears stopped working just out of the blue. In my case it was a bad torque converter lockup solinoid. Swapped the solinoid changed the filter and was golden

Which filter ?
How many solenodes are in the picture here ? If I just wanted to never ever visit problems in this area again ?
When my 10 year old Samsung TV no longer turned on/off with the remote - I pulled it apart and replaced ALL the transistors - (well I pulled the TV apart but I had someone with better eyes than mine do the soldering).

The transmission filter I believe.

I believe there are 3 solenoids for shifting. I'm a stick shift guy so I know little about automatics. Most folks replace the solenoids as a set. As I understand it it's not too difficult a job - just a dirty one.

Thanks - we are not rich - but we are not poor (although I will tell you that our retirement income is a fraction of what that cop who didn't go into that Parkland school is receiving - 8700 USD/month).

I wish someone would come out with a check / suggestion list for Jeep's of a certain age. For example - solenoids don't sound particularly expensive - so why not replace them every 10 years or so ?

Hahaha - Most folks aren't like us (people who love their 20+ year old Jeeps) and most vehicles are not XJ's, so 10 years is the life expectancy of most vehicles.

Is 8700/m what the Parkland cop is getting? That's more than I make in a month before taxes and benefits with what I think is a pretty good job!

Fingers crossed - mystery solved. We were down 2 quarts of transmission fluid...