Diagnose Rough Start

Sep 14, 2022


4.0l, 5spd, no CEL codes, runs completely without issue once started Battery is a cheaper everstart, unsure of age Terminals/connectors could use a good cleaning, but don’t look terrible

I’ve had the Jeep for about a year now. The Jeep consistently starts on the first key turn but seems to struggle on the first turn over. Some cranks it struggles once then starts fine. Other times it cranks for a few seconds before starting. Doesn’t matter if the engine is cold or running temp, the issue is consistently present.

I plan to clean the IAC, but before I start testing fuel pressure, replacing sensors and/or the battery, I wanted to get feedback.

Videos: Cold start back to back. First start you hear the struggle on the first turn but it fires up. Second start cranks for a few seconds and then starts.

This is just a few minutes later. First turn still struggles/coughs, but starts/runs fine.

Update 2022-09-18: On the way home from softball on Saturday, the Jeep would not start in the QT parking lot. Assuming it was the battery, my FIL came to provide a jump. With the vehicle batteries connected, nothing changed. No clicks, no noises whatsoever attemting to start. He towed me home, I pulled the starter and the battery and took them to the auto parts store. The battery tested fine and they had a starter in stock. I had it installed in less than ten minutes and it fired back up. The hesitation at start were just the warning signs of the starter dying.