'96 XJ w/ 186k miles here and I'm just starting to get a short hesitation to accelerate after say stopping at a stop light. It's only happening at like maybe one out of every 40 stops or so but it's getting frequent enough that I'm guessing it's gonna get worse over time.

Typical behavior for my XJ is to starting rolling forward by itself after I let off the brake, even before hitting the gas. It does that 100% of the time. What I'm seeing now though is that sometimes when I let off the brake it just sits there until I hit the gas. Most of the time it starts going soon as the gas pedal is pushed. But other times it will hesitate for a second and something will clink and it'll lurch a little as if it's just going into gear.

Sound familiar? Hope so.

Problem is it's not doing this often enough to show to a mechanic, but I know it's gonna have to be addressed at some point.

What does this sound like and how can I start investigating this?

 

'96 XJ w/ 186k miles here and I'm just starting to get a short hesitation to accelerate after say stopping at a stop light. It's only happening at like maybe one out of every 40 stops or so but it's getting frequent enough that I'm guessing it's gonna get worse over time.

Typical behavior for my XJ is to starting rolling forward by itself after I let off the brake, even before hitting the gas. It does that 100% of the time. What I'm seeing now though is that sometimes when I let off the brake it just sits there until I hit the gas. Most of the time it starts going soon as the gas pedal is pushed. But other times it will hesitate for a second and something will clink and it'll lurch a little as if it's just going into gear.

Sound familiar? Hope so.

Problem is it's not doing this often enough to show to a mechanic, but I know it's gonna have to be addressed at some point.

What does this sound like and how can I start investigating this?

 

Does it drive perfectly in every other situation?
Does it rev fine when you press the throttle pedal or does the engine feel like it stutters or just a lack of power?

Your description of the clink and lurch is making me wonder if you may have a gearbox solenoid starting to go funny (or the electrics to it) and it is actually in 4th gear, then manages to engage Sol #1 and gets 1st. The only way to test this would be when it happens, put the selector in 1 and see if it goes into gear and sets off as normal. As you say it's infrequent, this may be difficult to test and would take a while or catching it in the act to make findings more conclusive.

 

It sounds like a lot of things. Any CEL? How is the engine running? This might be a trans issue as likely as an engine issue.

I'd start with the free and easy stuff:

Pull engine codes (search here for how). Clean the IAC and TPS for starters. Test both. Clean all grounds. See Cruiser's tips, and do all of them.

 

Ever adjust your throttle valve cable? Clean your throttle body?

Replaced ALL: plugs, wires, cap and rotor in the last 30,000 miles?