Just wanted to share my recent experience with the group. I have an e30 i recently purchased. It had a hard start and cold idle issues. It was harder to start cold than hot, but still had hard start hot. As the weather has cooled it was even harder to start. It was also a little hesitant when I first hit the throttle. The temp sensors had been replaced in the past couple months, so I was pretty sure that wasn't it. So I decided to use seafoam then change the plugs to see if that had an affect. Next step was going to be to test the fuel pressure and check for vacuum leaks.
Queue the drumroll...
When I pulled the vacuum line off the fuel pressure regulator (FPR) there was raw fuel in the line. Key indicator of a failed FPR. I replaced the FPR, problem solved. Car starts normally, cold idles correcty, no hesitation in the throttle.
Queue the drumroll...
When I pulled the vacuum line off the fuel pressure regulator (FPR) there was raw fuel in the line. Key indicator of a failed FPR. I replaced the FPR, problem solved. Car starts normally, cold idles correcty, no hesitation in the throttle.