1994 Discovery, service questions

[Wilson1730]

I have owned my 1994 Discovery for over a year now and enjoy the vehicle very much. I have also decided with this vehicle to be the one who maintains it the majority of the time. The Disco has 153,000 miles on the vehicle and 40,000 on a rebuilt motor with a new 4.6 lower end from brittish pacific. I change the oil every 3k miles and top up fluids when they need it, ie brake fluid, power steering et cetera and I haven't had many issues.

I just replaced replaced the rear pinion seal and about six months ago my alternator went out. For these services I took them to a land rover mechanic.

At present my tachometer bounces and the idle feels a bit high. I was planning on trouble shooting the bouncing tach on my own and was wondering if it would be prudent to have the vehicle inspected and tuned. And if I shoud make this a habit moving into the future, say once a year. I was also wondering if its a good idea to get a compression test done? I am a novice when it comes to working on vehicles. Good with a wrench but always look for help with the details. Thanks for the help.

 

[sedat]

whats the l idle when warm in neutral?
tach could be the cluster itself or something going on with the alternator.

Compression tests are fairly easy to do, but they arent all that accurate. a leak down test would be more thorough.

 

[proper4wd]

It would be very beneficial to have a LR mechanic look it over and set the tune for you. Here are some of the main things you should have properly set.

1. Base idle. This is a good test of a LR mechanic, if he does not know how to do this or what it means find another one. It is a simple process but is specific to the older 14CUX EFI.
2. Clean out PCV system, including the trap on the RH valvecover. You may look at replacing the hoses and elbow depending on the condition.
3. Set the kickdown cable a little tighter than LR spec. This really increases the drivability.
4. Set the base timing a little on the aggressive side. This will require some fine tuning to your set up especially with the 4.6

 

[evilfij]

The new alternator is failing. Outside of brand new Magnito mirelli ones, they all crap out.

 

[kferg]

Start simple. Look for vacuum leaks and clean the IACV valve. I had similar idle issues driving me crazy on my '95 and finally realized the vacuum hoses were old and shot. Once I replaced those she idled much better. You should check all of those and make sure the hose clamps are tight first, a loose fitting can cause issues. If you've never chased down vacuum leaks you can do it easily by sealing the airbox, disconnecting a vacuum line and puffing on a cigar and blowing the smoke into the end of the line. If you have leaks smoke will escape where there is a leak.

 

[proper4wd]

If you've never chased down vacuum leaks you can do it easily by sealing the airbox, disconnecting a vacuum line and puffing on a cigar and blowing the smoke into the end of the line. If you have leaks smoke will escape where there is a leak.

With a glass of scotch in the other hand! This may be my favorite improvised Land Rover diagnostic I have ever heard.

 

[kferg]

I didn't think of the scotch, that would help with the taste left in your mouth. Wish I could claim credit for the idea but this one came off YouTube and works well.

 

[Wilson1730]

Thanks guys, I'll work on these things and get back to you. Thanks for the help.