[1980RR]

I have a 1999 Grand Cherokee w/ 4.0.It has 49,000 on the clock. Sometimes I get a clunk into gear and it starts a little harder than I'd like. I'm going to put in some new plugs and do an oil change while I'm there. A friend mentioned removing the throttle body and cleaning it. Thoughts? Anything else I should change/service while I'm under the hood? I'm new to jeeps.
Thanks in advance,
Jay

 

[nate379]

I know the ZJs will do it. It's something in the tranny, I can't remember know though. Personally I wouldn't worry about it if it's just a mild "clunk"

 

[WJ]

That clunk your refering to is just slack in the tranny linkage, dont worry about it nothing is broken.

 

[valkyr]

Do you know how old the battery is?

Hard starting may be related to a fading battery. With all the computerized controls in the WJ, a fading battery will also have an impact on the way the engine runs.

Joe V.

 

[1980RR]

The battery seems fine. When I say hard starting I mean it rolls over great but takes a few turns to fire. I'd like it to fire up within 1 or 2 revolutions. Is this too much to ask for?

 

[valkyr]

The battery seems fine. When I say hard starting I mean it rolls over great but takes a few turns to fire. I'd like it to fire up within 1 or 2 revolutions. Is this too much to ask for?

Another possibility is fuel filter/fuel pump not keeping fuel line pressurized. There are valves in both that are supposed to do that. I hope it's not the fuel pump, since it's on top of the gas tank and not a lot of fun to replace.

Try this: Turn the key to activate accessories, hold it there for 10 seconds, then go the rest of the way to start. See if it fires right up. The 10 second pause allows the pump to repressurize the fuel line.

I took my '99 to the dealer over a year ago for long cranking problem. They did a fuel pressure test, suggested replacement of the fuel pump, which I declined. Strange thing is I haven't had a problem since then.

 

[D Fab]

Had the same problem with the long crank time before start up. Just got back from my shop and they said that there is a bad seal around the fuel pump. It allows the fuel pressure to drop too far when the Jeep sits for too long and thus the long cranking. Apparently this is a common problem, with the '99 WJ at least, since he said there was a bulletin about it and that there were kits to correct the problem. Luckily I have a warranty to cover fuel pump problems so they are just replacing the whole thing.

 

[whatroads]

You may not think you need it. However, I would replace the plug wire with some good 8mm core wires from Accel or Jacobs Electronics. I could not believe the difference they made on my YJ

 

[ViNcE-ZJ]

WJ's dont have plug wires, they have a coil pack. You could replace the coil pack, but I really wouldnt worry about it till closer to 60,000 or more.