New OPDA, now poor idle

[Goatman]

Changed out my OPDA. Turns out PO had already done it. So I have a spare. But there was a little rotational play in it. Swapped out as per video and sticky. Now the idle wants to sit around 500 rpm or a bit lower. Crappy starting off in first now too. Thinking I need to rotate it a bit to clear this up. But which way? Or should I be doing some other adj.? I did swap out the electrical pickup when I put the new OPDA in.

 

[mots]

What procedure did you follow exactly? (links) I've actually never seen any vids or instructions that are complete, or at least explained in detail properly. I provided these steps about a week ago in another thread. Let's compare these to what you did first.

https://wranglertjforum.com/threads...nd-oil-pump-drive-assembly.24845/#post-412951

 

[rasband]

Did you get it to TDC when you swapped? My semi-educated guess is that you need to get to TDC and check if the OPDA alignment holes are aligned (as a sanity check if nothing else).

 

[Goatman]

Got it to TDC.alignment holes were aligned. Made sure the existing OPDA alignment holes were in perfect alignment. Used that plastic pin it comes with. Made sure new OPDA had perfect alignment too. The existing OPDA had a slight bit of rotating play. Like the amount found in a regular distributor when changing points. New one had the same but of play when installed. Thinking the new OPDA needs just a slight bit of rotate either clock or counter-clock wise. Don't know witch direction to turn it that would be "advance". Or if some other way of getting it to smooth out and get the idle back. If it was a distributor then it would just need a degree or two of advance. It is basically the same thing just doing it a different way, right? I know it was installed correctly. I'm just not up on the newfangled way of these computers.

 

[mots]

Are you getting a CEL/code now, or did you at first? P0016 (Crankshaft Position - Camshaft Position Correlation) would be the code if the computer isn't happy with the new orientation. The P0016 won't typically pop until you get up to operating temp. Like @rasband suggested, I'd put it back at TDC again and see if something is off with the OPDA hole alignment and try again.

 

[Goatman]

No code. Other than the idle dropping and a bit of a stumble taking off it sounds and runs great. I am 100% confident the swap is correct. If there wasn't that bit of rotational looseness in both the original while installed and the new one having the exact same bit of wiggle when it was installed I would think something else was the problem. So when you pull the top of your OPDA there is 0 movement of the round internal part? It is tight to the cam gear and won't move at all? The wear pattern on the old one looked great. I don't think I am describing the bit of play correctly. It is just like the bit of movement in a distributor of you try to move the rotor a bit. Rotating the housing adjusts the timing. I double (triple) checked the TDC and the pin slides in perfectly every time.

 

[rasband]

So when you pull the top of your OPDA there is 0 movement of the round internal part? It is tight to the cam gear and won't move at all?

There’s a slight rotation of the whole unit (while keeping the gear plastic pin in), yes. Due to the gear shape. Did you keep the “pin” in your new one during install or allow the gear to rotate as you removed the old and placed in the new?

What year is yours?

 

[Goatman]

Pin in the whole time including tightening the lock bolt at the block. But...onc the pin is removed there is a small amount of free rotation of the part the pin goes into. Exactly the same amount as the old one had while it was in the Jeep before I rotated the crank for proper alignment to insert the pin from underneath. This is once again my question. Does no one else's have that bit of free movement when bolted in place? It seems if you don't then the helical drive gears must be in HARD contact with each other and would wear out quickly

 

[Chris]

Sounds like the timing is off. Time to align everything to TDC.

 

[toximus]

Which sensor are you using? I've heard of issues using aftermarket sensors.

 

[Goatman]

Using sensor that was on the original OPDA.
So NO ONE has ANY bit of freeplay in theirs?

 

[mots]

The rotational free play you mention sounds normal to me. Mine didn't have much, but there was tiny bit. I can't see how this matters though, since its a slave to wherever the camshaft takes it. If your wear was fine on the camshaft and OPDA shaft that you removed, it all sounds normal to me. The OPDA I removed had more vertical play than the Crown unit I replaced it with. If you pulled on the shaft, it would move up and down a bit (that's what she said!). That said, I have no idea of whether that was really a problem or not, but mine was acting up big time (limp mode over 3k) and the issues went way after replacing. I thought it was likely evidence that the bushing was failing and allowing for more movement. When things heat up (or in really cold conditions), it may have wobbled laterally as well, causing the tone ring to wobble. Not good. It will actually hit the camshaft sensor and make a noise in extreme wobble situations.

The downside of doing the OPDA at home is that we don't have a scanner to plug in and do the final calibration. Perhaps find a dealer or shop that does and have them spin the OPDA housing to 0 degrees correction (there is small window of rotation allowed until the P0016 code pops when it gets to operating temp. You may be on the edge and have somehow advanced or retarded your timing enough that just off from ideal, but still in the window that the PCM likes to see from the last calibration.

 

[Goatman]

Ok. Then I will quit bitchin about it and run the girl. Hell, maybe it's in my head or some other small glitch. I've put at the most 10 miles on since the OPDA change. Could be just everything settling down after the battery disconnect.

 

[mrblaine]

Pin in the whole time including tightening the lock bolt at the block. But...onc the pin is removed there is a small amount of free rotation of the part the pin goes into. Exactly the same amount as the old one had while it was in the Jeep before I rotated the crank for proper alignment to insert the pin from underneath. This is once again my question. Does no one else's have that bit of free movement when bolted in place? It seems if you don't then the helical drive gears must be in HARD contact with each other and would wear out quickly

There is generally a small bit of free play. Also why the PCM has the ability to compensate for timing about 10 degrees or so either side of 0.

 

[mrblaine]

The rotational free play you mention sounds normal to me. Mine didn't have much, but there was tiny bit. I can't see how this matters though, since its a slave to wherever the camshaft takes it. If your wear was fine on the camshaft and OPDA shaft that you removed, it all sounds normal to me. The OPDA I removed had more vertical play than the Crown unit I replaced it with. If you pulled on the shaft, it would move up and down a bit (that's what she sad!). That said, I have no idea of whether that was really a problem or not, but mine was acting up big time (limp mode over 3k) and the issues went way after replacing. I thought it was likely evidence that the bushing was failing and allowing for more movement. When things heat up (or in really cold conditions), it may have wobbled laterally as well, causing the tone ring to wobble. Not good. It will actually hit the camshaft sensor and make a noise in extreme wobble situations.

The downside of doing the OPDA at home is that we don't have a scanner to plug in and do the final calibration. Perhaps find a dealer or shop that does and have them spin the OPDA housing to 0 degrees correction (there is small window of rotation allowed until the P0016 code pops when it gets to operating temp. You may be on the edge and have somehow advanced or retarded your timing enough that just off from ideal, but still in the window that the PCM likes to see from the last calibration.

We had a Crown unit completely lose the thrust washer on top of the driven gear. That allowed the shaft to move up far enough that it would walk out of time.

 

[mots]

We had a Crown unit completely lose the thrust washer on top of the driven gear. That allowed the shaft to move up far enough that it would walk out of time.

Great, another thing I have to worry about! I'm sure you've seen those threads on other forums where guys have oil running through them etc.? The 2005/2006 models have to be so lucky they (Chrysler\Mopar) changed the design. Although I've heard about some OPDA failures on earlier DI models that have them, they seem to be higher mileage and more understandable.

 

[mrblaine]

Great, another thing I have to worry about! I'm sure you've seen those threads on other forums where guys have oil running through them etc.? The 2005/2006 models have to be so lucky they (Chrysler\Mopar) changed the design. Although I've heard about some OPDA failures on earlier DI models that have them, they seem to be higher mileage and more understandable.

To be clear, that is the only one I've ever seen with the problem. Never heard of it on any boards either. If you look at one, it is hard to see how the thrust washer could completely go away and let the driven gear wear away the bottom of the aluminum housing. If we were the ones who installed it, I'd really suspect that it never had the washer but I know it did.

 

[Peter Panagakos]

You did not mention lining up the new OPDA with the engine block in the same spot as the old. I remember putting in a new OPDA on my prior Rubicon and I made a mark on the engine block so I could put the new OPDA in the same spot before I tighened the locking tab down. This was in addition to making sure the hole lined up for the pin.

 

[Goatman]

It would make no difference if the new one was off by a tooth in the install. If everything was in time and no obstruction to the OPDA or wires. The cam dosen't really care what tooth touches what tooth. If everything is timed properly to the 1 tooth it is timed to the 2 tooth, etc. BUT ....

While driving down the road I mis-shifted from 5 to 6. I actually put it into 4 and up-reved the engine. POOF idle smooth as silk @750 rpm. Have no idea why the one should effect the other, but now she runs like a top. First time I missed a shift on her. Also first trip over 2-3 miles. Maybe that had to do with it. Mr. Blaine, any reason or just odd chance? Either way, I would like to thank you all VERY much for sticking with me through all of this.