M42 Issue

[BMWManiac]

Check your new intake boot....I installed a new one in my 91 318i and it ran like it had a vac leak...turned out, there was a plug in my old boot that I didn't move to my new boot....

If that doesn't work, check your ignition wires (or are you running coils?) I found a hole in one of the boots that was causing the engine to misfire due to the hole in the boot causing arcing with the valve cover.....look for white spots!

[dadnkid]

i had this same problem with my 1994 318is when i first got her from this mom and pop car dealer for 2gs. This problem sisnt happen until i got her home. and since the car was a "AS IS". there was nothing i could do. But, car would start, rev up to like 1500 rpm then back down to 0 and shut off. It turn out that i needed higher octane. since it was only a 1/4 tank. i filled up with preimun and put in octane booster. started car and it did the same thing as before. i started again and gave it a little gas at about 2000rpm. then i let go of gas and it was fine. since then, i use preimun all the time. maybe this will help u