[Louie4]

A random thought popped into my head today. I was not even thinking about it. The distributor on a 4.0L has the cam sensor in it. It controls fuel pulse sequence. There is a hole in it that a pin goes into for alignment. It should be easy to verify if it is correct. Bring the engine to #1 TDC and pop the distributor cap of and verify that it is aligned.

I can do that now. Just read my fuel pressure while running. It’s 38 psi. When I pull the FPR vacuum line off it jumps to 42 psi. I kept seeing that it should be a 10 psi jump.

I waited for a bit to see if my fuel pressure bled off but no. Holds steady at 38 psi.

 

[Louie4]

Here is the distributor…

It’s my 1993 distributor. The 1999 one was a bit different on the cam sensor.

 

[Boojo35]

I know that this is a TJ so it may be slightly different but what I think needs to be verified is that with the engine at TDC does the 4.0L alignment hole line up with the hole in the base of the distributor. If not, this guys shows the resolution of rotating the gear 180 degrees by removing the roll pin.

Maybe this helps, maybe not. It should be very simple to verify though.

 

[Luuca]

A random thought popped into my head today. I was not even thinking about it. The distributor on a 4.0L has the cam sensor in it. It controls fuel pulse sequence. There is a hole in it that a pin goes into for alignment. It should be easy to verify if it is correct. Bring the engine to #1 TDC and pop the distributor cap of and verify that it is aligned.

Can confirm. The YJ Alternator will work in the OPD hole. Timing is off.

 

[Louie4]

Worth a shot and I did monkey with the distributor and had to pull it out a couple times, not to mention it was in my ‘93 4.0L and is now in the ‘99 4.0L.

I’ll pull the distributor tomorrow. I think timing could definitely be an issue.

 

[fishadventure]

Can confirm. The YJ Alternator will work in the OPD hole. Timing is off.

Am I misremembering that the timing marks on the later 4.0s reference differently than the OBD1 4.0? Or am I confusing another motor? Something is ringing a bell in my head but I just can’t remember what it is.

 

[Luuca]

Am I misremembering that the timing marks on the later 4.0s reference differently than the OBD1 4.0? Or am I confusing another motor? Something is ringing a bell in my head but I just can’t remember what it is.

Alls I know is that the trailing edge of the rotor should be JUST PAST the #1 plug post when done correctly. Seems wrong, but that's what works for me.

Try That.

 

[Louie4]

So…I took the #1 plug out and found TDC. Then noticed my rotor was 180 degrees out. I pulled the distributor and checked for the sync home but only found a threaded hole bolting something down inside.

So, I rotated the distributor so my rotor was pointing to #1. The damper notch was on 0 and I was confident I was on the compression stroke.

tried to fire it up and didn’t crank.

I also found some exposed wires on the distributor plug. Taped Those up before trying to start it.

pics…

 

[Louie4]

How it sits now. Black mark is #1

 

[Louie4]

So, I’m not sure if I was on the compression stroke. I’m racking my brain and can’t figure out what the issue is. I will pull the distributor and follow a formal procedure to get it installed correctly. I’m just going off my own head.

 

[93YJ4FUN]

It might be time for a live zoom consult. You are obviously skilled enough. But sometimes we get into our own head and miss something we normally wouldn't.

With the brains and experience available here, it might help to get a second pair of eyes on it.

 

[Boojo35]

So…I took the #1 plug out and found TDC. Then noticed my rotor was 180 degrees out. I pulled the distributor and checked for the sync home but only found a threaded hole bolting something down inside.

So, I rotated the distributor so my rotor was pointing to #1. The damper notch was on 0 and I was confident I was on the compression stroke.

tried to fire it up and didn’t crank.

I also found some exposed wires on the distributor plug. Taped Those up before trying to start it.

pics…

Your engine was running, there is no way that your distributor was 180* off at that time. It would not run 180* off as you have found since you turned it 180* and it now does not start. You were not on the compression stroke. You need to rotate it back 180* to where it ran. And then some. See below.

I spent a couple of hours researching why your distributor guts look different than I expected. Your pics helped a great deal and led me down the rabbit hole. Earlier distributors I have found do not have the plastic cam sensor under the rotor that pops off to expose the alignment hole. You have a different distributor.

Anyways, I found this. Look at the alignment mark, the white line as compared to the square notch on the outside of the distributor. You are one or two teeth off the way you are putting your distributor in. You need to rotate it clockwise to match the marks that this guy has. Your rotor is pointing pretty much in the middle between that notch and the plug in the side of the housing. His mark is almost to the notch.

There is your secret sauce. It may have to move a tooth. It may have to move a couple. You are almost there.

 

[Boojo35]

It might be time for a live zoom consult. You are obviously skilled enough. But sometimes we get into our own head and miss something we normally wouldn't.

With the brains and experience available here, it might help to get a second pair of eyes on it.

Or just wait on me to do my diligent research and come up with a solution. LOL. The inside of that distributor was by no means what I expected to see. When you pull the cap off a 4.0 you see a rotor and a plastic plate that is the cam sensor. You lift the cam sensor off and you see the alignment holes. It took me a bit to figure out that he does have the correct distributor for his year. I suspected it was wrong. Nope, the older ones looked like his. Not sure what year they changed out. Maybe his is a pre HO. I think that happened in 95.

92-94 FSMs seem to be very elusive. I would love to lay my hands on some PDF versions of them. If anybody has them. Hook me up.

Anyways, his distributor was within a tooth or two of where I know believe it belonged. He has to rotate it a bit clockwise to get there. I know that @Luuca has referred to this very thing. Kudos Tim.

 

[93YJ4FUN]

Boojo35, you have a pm

 

[Luuca]

Your picture of the rotor and your #1 mark would be perfect for a 70s Chevy. You need to pull it out and rotate it one tooth forward then stab it. It's counter intuitive, but the rotor blade should be just PAST the #1 plug post when correctly installed on the 4.0.

Tom, my fab/work/jeep buddy is a Chevy guy and would ALWAYS stab the distributor like you have it. Dead center on the #1 post. Then it would crank and crank and crank, but not fire.

Remember spark is not controlled by turning the distributor. It is controlled by the ECU. Pull it out and set it up with the rotor blade Just past the #1 plug post, then come back and tell me how brilliant I am.

Tim

 

[Louie4]

Thanks so much guys. I was getting discouraged big time. I can’t wait to come back and let y’all know how brilliant you are 😉. Now I just need time to do it. Spring break for my daughter is next week so we’re going to San Diego and Legoland.

 

[Boojo35]

Damn. Coming back and looking at this thread, my attachments of this pic did not stick. Look at where his mark is. Luuca has nailed it. This should give you a very good visual reference of where it needs to be pointed.

 

[Louie4]

I’ll try to get it installed correctly tomorrow and take pics.

 

[Boojo35]

Sorry. Now I see the pic. Effing shady back country internet service bites me again.

I would not trade my location for anything though. LOL.

We have peace and quiet. Shoot our guns in the yard. Hunt at home. Lots of wildlife.... Hell.... run around naked in the yard if you choose. Nobody is going to see you. .

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I would rather have tan lines personally as opposed to a sunburned and blistered and then peeling thingy though. JS. I like my thingy to be ready for service rather than in healing mode..... Then again... Healing mode can be a good thing if it is healing for the right purposes.... the sun is not one of them IMO.

 

[Louie4]

Sorry. Now I see the pic. Effing shady back country internet service bites me again.

I would not trade my location for anything though. LOL.

We have peace and quiet. Shoot our guns in the yard. Hunt at home. Lots of wildlife.... Hell.... run around naked in the yard if you choose. Nobody is going to see you. .

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I would rather have tan lines personally as opposed to a sunburned and blistered and then peeling thingy though. JS. I like my thingy to be ready for service rather than in healing mode..... Then again... Healing mode can be a good thing if it is healing for the right purposes.... the sun is not one of them IMO.

I do miss the country where my folks live. Peaceful and you can see stars when taking a whiz outside in the middle of the night. I’m sure there are spots like that in AZ but not so much in Phoenix. Definitely won’t be running around naked here. The sun is no joke.