All Cylinder Misfire Trouble shooting

October 05, 2025, 07:38:59 AM

Hi, I have an 86 8v gti engine code EV. I bought it not running in January, it having been sat for 6 years, and got it going again in the summer. I have driven it about 2k miles since but after about an hour of driving I start to get intermittent misfires of all cylinders simultaneously. My guess is the in tank pump, which I did replace before first getting it going, is overheating. If I pull over and sit for 10 minutes I can drive for another ~20 minutes without issue, If I fill up with fuel I can drive for another hour-1.5 hours without issue. I was wondering if anyone had experienced a similar problem, before I just swap out the already ‘new’ in tank pump?