TL : DR - Can where the disti and oil pump mate up get misaligned from the cam gear? I'm assuming yes....
New 4.0 installed by mechanic(had 227k miles and some issues that would only be resolved with a new motor). After a couple hundred miles during the break-in process, the CEL turns on. Scan codes and it's P1391. Mechanic says not a big issue, everything is running great, so bring it in next week and we'll get it figured out. He looked at it and determined that the distributor needed to be replaced as it's output was inconsistent. No big deal, order it, let's get this done, call me when you have the part and are ready to install it.
It's been a month without hearing from him and considering how busy his shop is and how long other things took, I got a bit frustrated and decided to swap it myself.
Did it the lazy man's way marking where the rotor was pointed. First thing I noticed was that the rotor was just *slightly off from the previous disti, but trying to adjust one tooth like what I had seen online meant that the flat key didn't fit into the oil pump. I chalked it up to maybe my vision... maybe that's where the rotor was supposed to be pointed. It took a couple tries but it started and ran fine. Only problem is it didn't fix the P1391.
Last night I decided to pull the disti and have a closer look at things and I noticed that my original disti had the alignment bolt "ears" ground off and had a different plate holding it down. It allowed for some adjustment, which I know is not needed. So that got me thinking, I wonder if it really was off by just one tooth and I need to swap back to the other disti that can rotate slightly. I swapped back and it ran rough this time. Great... I'm going backwards.
This morning I decided to go back to the new disti as it least it was running, even if it took a couple tries to start. But this morning it isn't starting at all. Turns over a few times but won't start. As if it's not firing at all and flooding. Installed a new ignition coil because I've replaced everything else on the engine and why not at this point try and have every damn part brand new. Didn't fix it. SO, I'm thinking somehow the slot in the oil pump got misaligned from the cam, and I'm off enough that none of the points are lining up with when the cylinders should be firing.
So, at this point, do I need to find cyl 1 TDC, manually rotate the oil pump "keyhole", then reinstall the disti so that it lines up with the 1 spark plug wire?
Really frustrated that what should have been a 30 minute job is now turning into a few hours.
New 4.0 installed by mechanic(had 227k miles and some issues that would only be resolved with a new motor). After a couple hundred miles during the break-in process, the CEL turns on. Scan codes and it's P1391. Mechanic says not a big issue, everything is running great, so bring it in next week and we'll get it figured out. He looked at it and determined that the distributor needed to be replaced as it's output was inconsistent. No big deal, order it, let's get this done, call me when you have the part and are ready to install it.
It's been a month without hearing from him and considering how busy his shop is and how long other things took, I got a bit frustrated and decided to swap it myself.
Did it the lazy man's way marking where the rotor was pointed. First thing I noticed was that the rotor was just *slightly off from the previous disti, but trying to adjust one tooth like what I had seen online meant that the flat key didn't fit into the oil pump. I chalked it up to maybe my vision... maybe that's where the rotor was supposed to be pointed. It took a couple tries but it started and ran fine. Only problem is it didn't fix the P1391.
Last night I decided to pull the disti and have a closer look at things and I noticed that my original disti had the alignment bolt "ears" ground off and had a different plate holding it down. It allowed for some adjustment, which I know is not needed. So that got me thinking, I wonder if it really was off by just one tooth and I need to swap back to the other disti that can rotate slightly. I swapped back and it ran rough this time. Great... I'm going backwards.
This morning I decided to go back to the new disti as it least it was running, even if it took a couple tries to start. But this morning it isn't starting at all. Turns over a few times but won't start. As if it's not firing at all and flooding. Installed a new ignition coil because I've replaced everything else on the engine and why not at this point try and have every damn part brand new. Didn't fix it. SO, I'm thinking somehow the slot in the oil pump got misaligned from the cam, and I'm off enough that none of the points are lining up with when the cylinders should be firing.
So, at this point, do I need to find cyl 1 TDC, manually rotate the oil pump "keyhole", then reinstall the disti so that it lines up with the 1 spark plug wire?
Really frustrated that what should have been a 30 minute job is now turning into a few hours.