Hi everyone. Yesterday I picked up my Tj with the new OPDA installed. I had this installed at my trusted garage. I have a doubt about it. In practice, the old opda was replaced with the new one, taking as a reference the top dead point of my engine. The mechanic told me that unlike the old OPDA, to put the new one in phase, he had to rotate the oil pump gear a few degrees. The engine runs more smoothly over the rpm, but I notice a difference compared to before, in practice, during driving, it seems that the engine is less nervous, while when it is at minimum RPM and I suddenly sink the gas pedal , takes some time to go up by rpm, between the moment in which the pedal sinks and the moment in which the engine begins to rise of rpm. It is not a long time, but unlike before, I notice it. At the same time, even when I turn the key to start the engine, it now has some more hesitation than before. Could this be related to the phase of the new opda different from before? Could my old OPDA phase have been changed?
Differences and doubt after new OPDA install
- Thread starter Angio4x4
- Start date
It could be slighly out of phase, but I suspect if it was out of phase, it would be noticeable. My OPDA is clocked at a different angle than the OEM one because the oil pump didn't line up and I was too lazy to turn it.
I suspect that might not be the cause of your issue. It's possible he/she disconnected the battery and the PCM is still in the learning stage. You can try resetting it by disconnecting the battery and turning on the headlights for a minute or so.
Generally an out of phase OPDA will cause more severe issues than that.
If he replaced the OPDA, he likely also replaced the sensor. You can try reinstalling the old sensor onto the new OPDA and see if it makes a difference (I doubt it will)
I suspect that might not be the cause of your issue. It's possible he/she disconnected the battery and the PCM is still in the learning stage. You can try resetting it by disconnecting the battery and turning on the headlights for a minute or so.
Generally an out of phase OPDA will cause more severe issues than that.
If he replaced the OPDA, he likely also replaced the sensor. You can try reinstalling the old sensor onto the new OPDA and see if it makes a difference (I doubt it will)
Hi, I thank you for the answer, I didn't disconnect the battery, however, I'm using the old sensor, I didn't install the new one. I don't know if it is slightly out of phase, but now the engine seems to turn really better than before when I drive. I only find this problem of delay in this condition, and that the engine is now calmer than before.
I was also thinking at the beginning, but then I realized that actually the delay between the accelerator stroke and the engine rpm is actually felt, and starting the engine takes longer than a key to get it going.
Thank you, I'm studying what you posted to me. Tomorrow I will print everything and take it to my mechanic to understand what he will tell me about it.
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Perfect, I spent just over an hour translating everything into Italian and studying what the manual foresees. I think the problem is not the point 0 of the phase, which the mechanic has taken to center, but I think the reference piston is wrong, he didn't remove the spark plug from the first piston, but I think he took the zero on the next one. Based on your explanation and what I read here, I think this is the problem on my Tj. Tomorrow, I will ask him for information about it, and I will bring him this manual. Thanks again for the great help provided.
Good evening guys. Today I showed the Tj to my mechanic, and actually he could not say that the problem did not exist, tomorrow he will repeat the alignment procedure with the manual. We hope well.
You or your mechanic may already know this, but when following the instructions on the service manual, there are two different top dead centers for cylinder #1. Make sure you get the compression TDC.
Good evening to all. Guys, the problem seems to be solved, the mechanic had taken the deadlock of cylinder number 6 instead of the number 1. Now everything seems to have returned to normal. Thank you very much for the advice and guides, they were fundamental to solve this problem. I will continue to try the Tj in the next few days, and I will give you updates about it.
I would still find a mechanic that knows where #1 cylinder is located.
Under that circumstance, the the plugs fire at the correct time because there are only 3 coils that each fire 2 paired cylinders on each crank revolution. So you get spark when you need it.
However, with the OPDA 180 out, I think the injectors are spraying fuel into the wrong intake port at the wrong time, in this case, feeding #6 when it should be #1 and similarly off for all the other cylinders.
I believe the cylinders are paired as follows: 1-6, 5-2, 3-4
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