Hello everone!

My dad has been fighting a problem with his 94 Maxima for sometime now.The engine starts up fine, idles smooth with no problems, but the second you put the transmission into reverse or if started from neutral, into drive, the engine quits. The situation is the same as having your manual transmission car idling in gear and abruptly engaging the clutch. The problem happens after the car has sat overnight or for long periods of time. I have found that after the car only idles for a minute or two, the problem goes away. I have also noticed a slight unburned fuel smell in the engine area but have found no leaks. The dealer claimed it to be a switch in the transmission that they happilly replaced for $400 and of course it did not fix the problem. He already ran through the typical engine stumble while accelerating problem, which the dealer found to be a bad injector. While this problem was being fixed, they also serviced the transmission and said it was in good shape.
The only other bit of info I can give on this problem is, I noticed after repeated attempts of engaging the transmission and having it die, on one attempt, the trans engaged the engine stumbled and chugged but did not quit, I moved it back into park, the idle smooth and normal, back into reverse and the problem was gone.

any input would be greatly appreciated and thanks in advance.