Land Rover Repair: 1995 land rover discovery, land rover discovery, valve job

Question
Hi John,

Today I had a huge surprise, when I applied
the brake,  it jumped about 3 times, and then
came to a stop!   A friend of mine said the same
thing happened to her, and the mechanics could
never figure out what the problem was.

Any ideas?

Also- I just had the AC control panel replaced,
and now the car has difficulty accelerating, and
a bit of a rough idle (only when I have the AC on)

I understand that rough idle and slow acceleration indicate a variety of possible problems.

( I read in a previous post that you said "Rough idle could mean timing chain worn, TPS sensor may need replacement, valve job needed/ And Slow acceleration indicates poor ignition which could mean injection problems")

My question is- why do I only experience it when
I have the  the AC on? And, why am I experiencing
the problems immediately after I had the AC repaired and the AC control panel replaced?

Thank you, thank you for your time!
Sincerely,
Danielle

Answer
Hi Danielle,

your problems are very interesting.  

The 'jumping' sensation you mention may be the brakes grabbing.  I'm not sure exactly what would cause this to happen. Maybe there was some lubricant on the rotor and the pads became momentarily useless.  Maybe the ABS modulator is malfunctioning, or perhaps one of your brake pads is at fault.  

You'll have to examine every wheel and brake to see what could be the problem.

As for the AC and your Disco's performance, most vehicles will experience a slight decrease in performance when the AC is activated.  Its only normal as the AC compressor becomes engaged and is an additional load that the engine must carry.

If the AC drags the engine's performance down significantly, there may be an underlying problem with the AC compressor.  Since you've had work recently performed on the AC, promptly return your Disco for further service.  Make sure they know that you have troubles when you engage the AC.

Best of luck,

JohnMc