My truck has one of the horrible Holly Pro-Jection 4D systems in it, and as you would expect the thing is very finicky. It hates to run when it's cold (below 40)... until it's up to full op. temp I have to restart it. If it's warmer out, it has no problems Well tonight it's about 5 degrees out and I got it started, got it warmed up, and drive it around the block a few times to test it out. It ran and drove fine, except it wouldn't ever really idle - it was hovering around 1200rpms in gear with no load, but it's always done that and the engine has a pretty hot cam. I got back into the driveway and decided to back out again to test one more thing and as soon as I put it into Reverse, it stalled. As soon as I restart it and put it back into reverse it stalls again. If I get it into reverse with some throttle while holding the brake, it would try to stall out like it wasn't getting fuel for 1 second, fire up to ~2000rpms for 1 second, try to stall for 1 sec, and do this for 5-6 seconds and before it all-out stalled. It just seemed like the load of it in reverse was just enough to lower the RPMs enough to change something in the computer that set it into a "run" mode that it couldn't handle at only 5 degrees. My mechanic friend suspects the intake charge temperature sensor or the coolant temp sensor. Does anybody else have any experience with this horrible EFI system? Thanks!