Get a timing light,connect the power leads to the battery and the magnetic lead to the number 1 plug wire paying attention to how you connect it,most are directional.before you start the engine look down at the front of the crankshaft and familerize yourself with the timing marks on the timing cover.there is a dot or slot in the crank pulley that will correspond with the tiiming mark.start the engine and let it warm a bit then carefully shoot the light at the pulley,turn the distributor to line the marks up,im not sure of
the advance spec but 10 degrees before top dead center should do you,you can play with the timing to get it where you like it.good luck

 

FYI, these "new-fangled" computer controlled engines use the signal from a crankshaft position (CKP) sensor to the ECU to set the ignition timing. The ignition timing is programmed into the ECU. A camshaft position (CMP) sensor located in the distributor of your ZJ sends a signal to the ECU which synchronizes the fuel injection. Replacing the distributor will reposition the CMP sensor which will in turn mess up the fuel sync and make it seem like there is a problem with the ignition timing.

Once the CMP sensor is out of the correct position, it takes dumb luck to get it back. After you get it close enough to let the engine run (poorly), you need to get it to the dealership where they will use a scantool to help finish the job.

 

sounds like you have it one notch off. You can pick up a hayes manual to get you back in time correctly. You dont have to have a scan tool to get it right. The timing is controlled by the ecm so actually you just get the number one piston all the way to the top in the cylinder which you should have a mark on the balancer that will line up with some timing marks and it shound be at zero or TDC. It will need to be on the compression stroke which means both valves will be closed when piston is coming to the top of the cylinder. That plug hole is a bit hard to get to with a finger but if you take the spark plug out and get a friend to bump the starter over while you hold your finger in the spark plug hole and when the compression blows your finger out of the hole it is on the compression stroke. then just turn the engine til it is all the way to the top of the cylinder and check your balancer and line the proper TDC mark up and pull the distributor and line the rotor button up with the number one plug wire and thats it. it will actually have to go in and when it bottoms out it will need to line up with number one plug wire and if its like my 93 4.0 the distributor will only bolt in one way. I think when it is in time the balancer will be at zero and the rotor button will pointing toward the 5 o clock position. Hope this helps

 

I am getting over limit on idle HC when testing for smog. Nothing else is wrong. New O2 sensor and plugs, cap rotor. I hear retarding the timing a bit and then get the idle back to normal with adjust screw on the throttle body will get it to pass. Is this true? Has anyone done this? I did a fresh oil change, air filter. HC at 2500 rpm is fine. It does have 203k miles but runs great. No vacuum lines loose.
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