ok. first of all i'm new to this forum. i joined because i am seriously losing my mind trying to figure out what is wrong with my car. 2001 grand prix gt 3.8 v6... 124k miles.
last summer i started having this problem. i will be driving and the tach will drop completely to zero. continues to drive just fine, but the RPMs stay at 0. once in awhile it will stall completely and shut off. it starts fine when i restart it, but obviously this is not a normal thing. when my mechanic hooks it up to his computer no codes come up. and of course every time he drives it there are no problems. last summer i replaced the fuel filter and then the fuel pump. it ran fine all winter so i assumed the problem had been remedied and that it was a bad fuel pump. however, about a month ago the exact same thing started happening again. driving fine, tach drops to zero, continues to run fine with RPMs at 0. occasionally the engine stalls and shuts off but it starts immediately when i restart it.
does anyone have any idea of what the problem could be??