My 88 240 started acting up when I restarted it after a trip to the store. Currently the car takes quite a bit of effort to start (starts about half of the time, better if the outside temp is lower). It runs very rough but if I raise the rpms to 1500 or more it runs quite a bit better. It is barely driveable as is, unless you can get it out on the highway and get the rpms up, it will not tolerate any low rmp throttle pressure, although it does not stall.

I have had to replace the AMM before, the symptoms this time do match match those exactly, but are similar. I have checked for vacuum leaks and have not been able to locate any, I have also cleaned and checked all the electrical grounds, replaced the coolant temp. sensor and cleaned and greased all electrical contacts and fuses.

I can't really think of any engine sensors that would cause this problem aside from the AMM (the hard warm starts seem to be Hall Effect, but that does not explain the rough idle), but I hate to keep replacing parts without testing anything. What is the best way to test an air mass meter aside from simply unplugging it? Unplugging mine does not change anything.

Greg N

Greg N