90jeepxjguy

I've searched and found little info/detail. What exactly is needed to convert from coil pack to distributor, I'm looking for specifics, like what sensors and harnesses are needed to do this swap? Please don't tell me it's not worth it or ask why I want to..just looking for answers not criticism. Thanks in advance for any answers

I AM GOD

I think you'll need a complete harness, computer, distributor,....etc, from a 97-99.

It will require a complete swap.

90jeepxjguy

So ill need pcm, harness, coil, and distributor..do you know what sensors I'll have to swap?

freegdr

Anything harness connect to should be grabbed.

Jeepin'_Aint_EZ

I'm still curious as to why....

Martlor13

I wanna know why as well.

Johnny808

The 2000-2001 XJ Cherokee are the only model years with coilpack (coil-on-plug) ignition system. The only real benefit of it was to try and get a more accurate ignition, for better fuel burn and economy, to see if prolonging the XJ project could be kept around despite more and more stringent emissions requirements; it was deemed infeasible, and after 2001, the project was scrapped. There's only so much you can do to a 4.0L inline 6 with two overhead valves per cylinder.

That said, if you'd like to swap from coilpack ignition to distributor ignition (which seems...interesting), here's what obstacles I see in front of you:

1. Camshaft position sensor synchronization. This is a huge issue for those with 2000s XJs because being off between the two will cause no-start conditions, poor idling, and misfire on all cylinders. The camshaft position sensor is located in the distributor for pre-2000 XJs, and is a magnetic pick-up type sensor. Although they both may read 0-5V reference voltage, the distributor is driven by a drive gear on the camshaft, which needs to maintain the same teeth-to-teeth gear ratio. Therefore, you may need a camshaft from the pre-2000s XJs to make sure it is properly timed to the distributor. I'm also unaware of what changes were made to the journals, bearings and camshafts themselves, meaning that the earlier camshafts may not fit in the newer blocks, or the camshaft drive gear/oil pump drive gear may be differently sized or toothed. If the block and camshaft are incompatible, you're better off swapping engines. Or, not swapping the engines at all.

2. ECU to gauge cluster interfacing. Usually with incorporation of a new electrical system/harness, things change on the user end as well; once again, don't quote me, but I'm pretty certain that the harnesses/pigtail connections will be different, so expect to get a matching gauge cluster along with the harness if you pull it. Which can lead to all sorts of problems in itself, the biggest one being incorrect mileage (mismatching mileage on DMV titles will almost always result in a salvage title). The biggest problem here is that the 97+ model year Cherokees have the updated gauge cluster, so your search for a distributor-ignition 4.0 with matching harness and gauge cluster will be limited to 1997, 1998 and 1999 Cherokees.

Quick question: are you planning on changing to forced induction? That's the only reason I can see for wanting to change to distributor -- to avoid ECU reflashes and tuning by advancing timing instead for a supercharger or turbocharger application.

90jeepxjguy

The shear simplicity of it and I can upgrade cap and rotor, coil, plugs and plug wires for less than a replacement coil pack, and I have an entire 99 xj donor I can get everything from to swap..And yes I have contemplated bolting an m62 or m90 on it as well

Martlor13

Well if you have your reasons for it. I personally wouldn't do it. Document it as you go.

Turbo X_J

Ignition coil for a '01 4.0 is ~ $55+ship from Rock auto.

Johnny808

My only concern for this undertaking is that you may swap everything over, tear your dash apart, swap out ECUs, drop in the distributor and put it all back together, and have a no-start condition.

I'd been considering an M90 installation on my 2001, but instead put it on my brother's 1994; I couldn't justify the $600 tuning for a $150 supercharger. However, I imagine the longevity of the engine after getting the tuning would be so much higher than just clocking the distributor back 10-15 degrees to make up for timing.

Usually the "shortcut" route is to find a distributor-ignition XJ and supercharge it, then clock back the timing; the harder, more expensive (and probably much better) route would be to get the injectors, wideband o2 sensor and everything set up and tuned to work with coilpack ignition.

I fear you might run into some serious problems changing your ignition system just to fit the shortcut option. I'd recommend parting out your donor XJ, getting some cash to fund your supercharger project, and working with ECU tuning.

Either way, keep us updated.

superbee1970440

Have you thought about a Dodge Viper ignition coil conversion? It seems simple enough. It gets rid of the coil on plug arrangement and will almost double the spark energy. Just a thought.

CoffeeCommando

Has anything been done on this? I am in the market for the same, for the same reasons. I'd like to know the problems encountered.

I'm about to get the ECU data printouts from All Data from my machinist for the 97-99 model years and see if it's an exact swap. As long as the pin outs are the same there's no need to go fooling with the wiring harness.

..if they aren't the same, I'd be more inclined to have a company manufacture a plug and play connector cross-pinout rather than pull harness and disassemble the dash. It's worth the few hundred bucks and there are companies that do just that.

My largest concern is that there are only so many ignition coil packs in circulation for the 2000 and 2001 setups. Distributors and wires, and all the aftermarket options you could ever want to tinker with, come with the distributor setup. I can't use NOLOGY hot wires and a custom ignition coil wired off of a power inverter regulated to DC with that manufacturer-only setup Jeep did do those model years. They made those model years worse in all kinds of ways. Changed the axle pinion, put pre cats right up by the engine causing excessive heat and misfires in cylinders 3 and 4, and the heat wears out the engine bay components faster over time (this is really where the injector heat sock comes from; cylinders 3 and 4 are the only ones with the exhaust ports right next to each other and they made the manifolds thicker so there is a lot more concentrated heat retention there as well). I had headers and reverted to the OEM 2000 exhaust manifolds and began my journey with cylinder misfires for the first time, and I had the pre-cats removed. The exhaust manifold setup isn't helping matters with misfires any.

Amateur hour in the engineering room for those years.

george.72

This is most likely a dead thread, but if anyone has answers, I actually want to do the opposite. Convert the cap/rotor distributor to a coil pack. Anyone have input to speed up my research?

00t444e

No need to swap gauge clusters the 97-01 ones are all interchangeable. I put a 00 in my 97.