Can you retrofit a distributor to a coil equipped 4.0?

[Bammo68]

This question relates to a separate stroker build post but I wanted to know if anyone had a clear, definitive answer on this one question as I am struggling to get clarity on it:

Can I retrofit a 2002 4.0 block with a distributor instead of the coil pack? I'm looking to use that '02 motor in my 1999 (suitably converted in terms of accessories etc). Is there any reason why an '02 block wouldn't work with a distributor in place of the coil packs? All the wiring and ECU etc is setup for a distributor right now and I don't want to change all that. I'm wondering here if it is as simple as removed the 02 camshaft position sensor that sits in the hole, fitting a '99 position sensor (which is a totally different type of sensor) and fitting a new distributor.


Cheers

 

[machoheadgames]

The distributor will fit in the hole, because the hold is the same across all blocks. So to answer your specific question, yes that would work fine.

Where you are going to run into trouble that you may not have considered yet is that the ‘00-‘06 blocks switched to a new accessory mounting using different brackets and different bolt holes in the block. AC moved over to the left side from the right side. The intake changed which I believe changed the PS pump mounting and I think the alternator bracket was different and the new alternator design meant for that bracket is for sure wired differently.

 

[Bammo68]

Yep I'm aware there is going to be some shennanigans with the AC and other stuff - wasnt aware of the PS pump mount but I have both sets and reckon I can solve that. I was just trying to eliminate one issue at a time and I couldnt think of a good reason why the distributor wouldnt work!

 

[machoheadgames]

Yep I'm aware there is going to be some shennanigans with the AC and other stuff - wasnt aware of the PS pump mount but I have both sets and reckon I can solve that. I was just trying to eliminate one issue at a time and I couldnt think of a good reason why the distributor wouldnt work!

Nah, you’ll be good on that one for sure. The oil pump drive, cam gear, and block hole are all the same.

Holes for older ignition coil style might not be there in the newer block - might need to find a different hole to mount to and extend wiring or build a bracket or something.

As for the other stuff, I think you’ll pretty much want the 2000+ alternator and its factory bracket. Need to change the wiring a bit to make that work.

AC lines - the ones from a 2000+ might work, since I believe the heater core location is the same place on the firewall. Wiring would need to be run over there.

Will need to use the 2000+ water pump from then on and associated fan clutch.

PS is the one I don’t know about, I want to say your stock pump won’t bolt up to the new intake and so you might need the later model. I do recall the PS also relies on the older water pump so you will probably be Forced to switch to the newer PS pump and bracket.

Either way I’m sure you can get it done, just wanted to make it known that it won’t be just a simple bolt up swap

 

[Bammo68]

So I have an '02 PS pump, alternator and AC compressor along with brackets. Extending the alternator wiring doesn't phase me as all. The bit that makes me hesitant is that I went to a *lot* of trouble to get AC added to my '99 and I feel like I would be throwing all that effort away, but its probably not that big a deal. The issue I had was that finding RHD '99 AC lines was basically impossible and I had to have custom ones fabricated that, of course, now won't fit the '02 placement and the oddball AC flanges on the condenser which are unique to '99 models. All do-able, but my dream of this being a simple swap is rapidly turning into a bigger project!

 

[Rickyd]

The distributor will fit in the hole, because the hold is the same across all blocks. So to answer your specific question, yes that would work fine.

Where you are going to run into trouble that you may not have considered yet is that the ‘00-‘06 blocks switched to a new accessory mounting using different brackets and different bolt holes in the block. AC moved over to the left side from the right side. The intake changed which I believe changed the PS pump mounting and I think the alternator bracket was different and the new alternator design meant for that bracket is for sure wired differently.

The later horseshoe intake is interchangeable with earlier ps pumps and accessories. But like you said,the bolt holes in the block are wrong

 

[Travis2024]

So I have an '02 PS pump, alternator and AC compressor along with brackets. Extending the alternator wiring doesn't phase me as all. The bit that makes me hesitant is that I went to a *lot* of trouble to get AC added to my '99 and I feel like I would be throwing all that effort away, but its probably not that big a deal. The issue I had was that finding RHD '99 AC lines was basically impossible and I had to have custom ones fabricated that, of course, now won't fit the '02 placement and the oddball AC flanges on the condenser which are unique to '99 models. All do-able, but my dream of this being a simple swap is rapidly turning into a bigger project!

@Bammo68 Did you ever follow through with this? I have a 2003 TJ with 4.0 and AC and I just had the same idea of swapping to a distributor with all these cam and crank shaft sensor issues.

 

[Bammo68]

I'm rebuilding the 02 block as we speak but still a few weeks away from assembly of those parts so unsure yet. I don't foresee any issues with the distributor side of things - but that's because I'm only using the 02 block, everything else is off my 99 motor...

 

[Travis2024]

I'm rebuilding the 02 block as we speak but still a few weeks away from assembly of those parts so unsure yet. I don't foresee any issues with the distributor side of things - but that's because I'm only using the 02 block, everything else is off my 99 motor...

Oh gotcha. I'm gonna do a little more thinking about that because it would be nice to not have to worry about cam or crank sensors, and I prefer wires over coil packs. One concern I have is possible PCM issues with no crank or cam signals, but I am not too sure what all those affect.

 

[mrblaine]

Oh gotcha. I'm gonna do a little more thinking about that because it would be nice to not have to worry about cam or crank sensors, and I prefer wires over coil packs. One concern I have is possible PCM issues with no crank or cam signals, but I am not too sure what all those affect.

You will still have to run the crank position sensor.

 

[mrblaine]

I'm rebuilding the 02 block as we speak but still a few weeks away from assembly of those parts so unsure yet. I don't foresee any issues with the distributor side of things - but that's because I'm only using the 02 block, everything else is off my 99 motor...

If it helps, a buddy put a low mile 05 in a 99. Fortunately he had all the accessories from both so he was able to mix and match as needed to get it all done and working.

 

[Travis2024]

You will still have to run the crank position sensor.

Oh okay. Which sensor controls fuel injector timing, would that be the crank or cam sensor?

 

[Bammo68]

And will your ECU be able to cope is the question I would ask? Does a later model ECU and wiring harness have the capacity to support the distributor and its style of crank position sensor which is a round flat thing that goes under the distributor... I can't actually recall if its even attached to the harness right now!

 

[mrblaine]

And will your ECU be able to cope is the question I would ask? Does a later model ECU and wiring harness have the capacity to support the distributor and its style of crank position sensor which is a round flat thing that goes under the distributor... I can't actually recall if its even attached to the harness right now!

No idea but the difficulty going the other direction is there are 3 outputs to the coil pack to fire 1 of the coils for pairs of cylinders. Without digging into it too far, I suspect that using those 3 outputs to trigger the single coil could get pretty interesting.

 

[macleanflood]

Easiest solution is just buy a 97 or 98.

Or as I posted in your other forum post, use Standard Motor Products or possibly Napa Echlin.

@Wranglerfix has either a tune or the replacement PCM is less sensitive to non-oem sensors.

-Mac

 

[Rickyd]

Easiest solution is just buy a 97 or 98.

Or as I posted in your other forum post, use Standard Motor Products or possibly Napa Echlin.

@Wranglerfix has either a tune or the replacement PCM is less sensitive to non-oem sensors.

-Mac

He could run an hei for amc 6's and a carb adapter if he really didn't want cam or crank sensors. If its fuel injected you need both sensors regardless of whether it has a distributor. Nevertheless its a fools errand

 

[mrblaine]

He could run an hei for amc 6's and a carb adapter if he really didn't want cam or crank sensors. If its fuel injected you need both sensors regardless of whether it has a distributor. Nevertheless its a fools errand

I am of the very firmly held belief that anyone who wants to move away from computerized vehicles needs to take their home computer, laptop, tablet, smart phone and any other device that connects them to the internet out into the backyard with a sledgehammer and a gallon of gas. After they get finished smashing them all into tiny bits, then set them on fire to render them fully unfixable, otherwise, there is no higher level of hypocrisy.

 

[hear]

I am of the very firmly held belief that anyone who wants to move away from computerized vehicles needs to take their home computer, laptop, tablet, smart phone and any other device that connects them to the internet out into the backyard with a sledgehammer and a gallon of gas. After they get finished smashing them all into tiny bits, then set them on fire to render them fully unfixable, otherwise, there is no higher level of hypocrisy.

I don't see the hypocrisy in needing computers to perform some functions and not wanting computers to perform others, but whatevs. Having seen you take this position before, I feel like you're conflating wanting to remove a Jeep's reliance on a computer with "all computers should be catapulted into the sun." My belief is that I'm fine relying on computers for a lot of things, but not everything needs it. Sure the 4.0L is better with a computer, but it's not like there isn't a precedent for cars operating without a computer. And a computer is hard to fix. Just look at like half the threads here. Crank no start? You're screwed, call Wranglerfix. Sure the PCM does lots of great things, but many of those things were handled for years and years through well-understood mechanical means.

I'm not saying ditch the PCM, but lets not act like the idea of decoupling computers & engines is completely out of left field and is the equivalent of somebody wanting to keep the dream of the 1890's alive. I don't expect to change your mind.

 

[mrblaine]

I don't see the hypocrisy in needing computers to perform some functions and not wanting computers to perform others, but whatevs. Having seen you take this position before, I feel like you're conflating wanting to remove a Jeep's reliance on a computer with "all computers should be catapulted into the sun." My belief is that I'm fine relying on computers for a lot of things, but not everything needs it. Sure the 4.0L is better with a computer, but it's not like there isn't a precedent for cars operating without a computer. And a computer is hard to fix. Just look at like half the threads here. Crank no start? You're screwed, call Wranglerfix. Sure the PCM does lots of great things, but many of those things were handled for years and years through well-understood mechanical means.

I'm not saying ditch the PCM, but lets not act like the idea of decoupling computers & engines is completely out of left field and is the equivalent of somebody wanting to keep the dream of the 1890's alive. I don't expect to change your mind.

However you justify it changes the hypocrisy none.

 

[hear]

However you justify it changes the hypocrisy none.

So there is zero room for the idea of "computers for some things" and "no computers for other things" to co-exist?

All or nothing, I guess. Bring on Skynet.