Semi-new member here. I have my in-law's '90 4x4 SE with 136k. I did a timing belt change, along with seals, water pump and thermostat, without any issues. I have replaced the spark plugs, dist cap, and rotor. I used the pathy over the weekend, without any issues. On Sunday, my wife was sitting in the car with the engine running, while I got some food, probably 30 minutes wait, and we drove home without any issues. The engine temp was fine throughout. Sunday night we decide to go do some grocery shopping, I went to start the pathy and it was noticeably rough, during idle and in drive, so I just parked it. I checked the codes with the self-diagnostic and got "55," so no issues recorded on the ECU. Any ideas?
I checked the plugs and they all look good. Checked the wires if they were loose, and all were good. I am wondering if the timing belt skipped? Though I think I had pretty good tension on it. I'm probably going to pull it back apart just for ease of mind to see that everything lines up correctly.
I'm so open to suggestions as I have no other ideas. I would have loved to get a code from the ECU pointing to the culprit.