I have a 1976 VW Beetle that is fuel injected with the 1600 engine. It runs fine for about 2 weeks and then starts to "buck" (Kind of like you let off of the clutch in the wrong gear and then try to add a lot of gas to it and it bucks like it is about to cut off.) It does this for a couple of days then it will run fine for another 2 weeks. We have taken it to our vw mechanic who works on old beetles and he tuned it up to see if that would cure the problem because it had sat for 6 months at a car lot until we bought it this past December. Then we posted on another site and a guy told us to check our type II sensor that is on the cylinder head. Well, we removed it and replaced it and found that it was corroded; well, no problems until today. It had been 2 weeks since we replaced it and it started bucking again and almost cut off. It does this bucking thing if it has been running a while at a constant rpm at a constant speed. I think that it is a wire that is loose after being run for a while and then connects again or it could be that when it gets warm, something either disconnects or tells it to try to cut off. My husband thinks that it could be electrical as well. If there is anything that you can tell us about this problem, please, all answers are welcome and highly appreciated.