Nissan Repair: 1995 nissan maxima engine shaking and running ruff., nissan maxima se, nissan maxima

Question
i have a 95 nissan maxima se, auto, 120k that the engine and body shakes pretty hard.   the vehicle was doing it before and replacement of two fuel injectors cured the problem.  under full throttle the car performs normally and does not shake.  while at idle and stopped the problem is most noticable.  accelerating away from a light you get what feels like a stumble in acceleration under partial throttle.  the vehicle did recieve a tune-up during replacement of the fuel injectors and was running normal.  can you get away with replacing only two injectors or should the whole set be replaced.  i read that the difference in resistences of the new injectors cause early failure of the other injectors.

one other small problem is oil smell in the cabin with the vent on.  any easy places to look for an oil leak that would cause that.

any help would be greatly appreciated.

Answer
Stephen,

I have found that replacement of all the injectors is pretty much the way to go to make sure you get all of the bad ones.  I find that when a couple fail the rest are not far behind.  I would perform a fuel pressure check and leakdown check to verify the fuel pressure and if any are leaking when you turn the key off.  No, replacement of some injectors will not cause others to fail.  But, if some fail the rest are soon to follow.  The oil smell in the cabin is probably the valve covers leaking and running on the manifold and then you get the smell of burnt oil.  Nothing too bad but I would replace the valve cover gaskets to get rid of the smell.