Slackdaddy

I noticed in general on this forum, people view the later 4.0's with coil packs as a negative. (setting the head issue aside).
Are not coil packs more reliable than a distributor with moving parts ?


Am I missing something here?


Give me the low down


Thanks,
Slack

Jeepin'_Aint_EZ

Well I'll tell you the one huge positive is how much cheaper it is to replace cap/rotor and plug wires versus the entire coil pack.

As far as performance, I don't really think there is a noticeable difference.

fijicorey25

Concerning reliability, I think it's a case by case basis. Some will say they've had no problems, other will say they have. You just have to weigh the pros and cons of each setup. Coil packs can only go on one way, therefore there's no way to mix up wires like a distributor can. However, finding top dead center with a coil pack is more of a pain. It's also not possible to pull a spark plug from just one cylinder with a coil pack, making diagnostic/troubleshooting more difficult in some cases. However, it's very easy to replace a coil pack, just unplug and replug.

It's just what you prefer to deal with.

Here's a post explaining some more pros/cons:

http://www.jeepforum.com/forum/f9/co...ibutor-514379/

Fred/N0AZZ

There are other issues with the 00/01 models that they alone have. All things considered the 99 model yr had all the best from older models and some that only came on a 99, generally a 97-99 are considered the belter choices.

nujeepguy

i have a spare 98 that runs great, 129000. like to use as backup for 331 2000 crack but what a job to make it fit the 2000??

extrashaky

Most of it is an unsophisticated reaction to something people don't understand. The gist of it is, "Wha? Ain't got no distribyooter? What kind of voodoo crap is this? Cain't trust it!"

The reality is that the coil rail gives you about the hottest spark you can get while involving fewer potential failure points. What's more, the computer in the '00 and '01 will often keep the motor running (with a CEL to let you know you have an issue) long after a Jeep with distributor ignition would have failed. Some people who like to pull their spark plugs out and look at them a lot get bent out of shape about having to take a few more bolts loose, but in the real world it's usually not necessary to do that very often. About the only real drawback is the cost of replacing a coil rail, but even that's not a huge problem with the lower prices you can find on the internet now.

The funny thing is that people with other cars spend a lot of money for aftermarket coil-on-plug ignition systems to get a hotter spark without the potential for mechanical failure, yet Jeep people whine about it when they get it from the factory.

fijicorey25

The fact that distributors have been around much longer relative to coil packs could definitely lead to this attitude. Whenever new tech comes out, droves of people say its stupid. This isn't limited to automobiles.

Jeepin'_Aint_EZ

The 4.0 didn't need to go distributorless. It can be viewed as one of those "if it ain't broke, don't fix it" kind of things. That's where I stand....

Martlor13

This section right here is real debatable.

extrashaky

Actually it did, and you can blame the US government for that. One of the reasons for going to the coil rail and the 0331 head was to help Chrysler meet stricter emissions standards. The '00 and '01 (and subsequent 4.0L motors) have a waste spark ignition system, which fires the cylinders on both the power stroke and the exhaust stroke. The result is more complete combustion of the fuel and cleaner emissions with no loss in power output. The distributor ignition system wasn't up to standard any more. Going to waste spark allowed Chrysler to continue using the 4.0L for several more years, when otherwise it would have had to have been replaced.

So even though it wasn't exactly "broke," it was rapidly approaching obsolescence. It doesn't hurt that the newer ignition is more reliable, and that the computer can keep the engine running when it ought to strand you on the side of the road. The only real issue was the original casting 0331 head, which was a problem with the casting and not problem with the coil rail.

Fred/N0AZZ

100% correct was the problems it added to the 00/01's in addition to double the o2 sensors, cats involved and the weaker, less clearance LPD30 front differentials. There are others also but many run them you seem to find more of them for sale than older ones.

extrashaky

To be clear, those issues have nothing to do with the coil rail and more to do with the overall design of the '00-'01 Cherokee. In 2000 the EPA version (like mine) didn't have the extra cats or O2 sensors. The waste spark ignition works just fine without them.

The low pinion front axle made room for the change to the exhaust to accommodate the extra cats, but again, that has nothing to do with the ignition. I have a high pinion D30 in the garage waiting to go into mine with my lift. The coil rail won't affect the installation of the new axle at all.