hey I am relatively new to this forum, I just recently purchased a 1993 Nissan Altima.im having problem with it idling, it idles terrible almost like a dead miss in gear or park doesn't make a difference aswell as it smells like raw fuel out the exhaust but if you give it gas anything above idle it runs great and it hasn't lost any power accelerating . I have done several diagnostic test checked fuel pressure (had 35psi), cleaned maf sensor, checked spark to all cylinders and all that checks out ok also replaced plugs, wires, and distributor cap. the car previously sat for awhile and was driven very little I am thinking it may need injectors. if someone could help point me in the right direction, thanks
Have you checked compression to be sure the engine is sound?
If the gas in the tank is old that will cause problems--typically when older than 3 months or so.
You can try running a few tankfuls of gas with Techron added or Gumout High Mileage Regane (it is 2x strength of normal Regane).
A more effective cleaning would be the professional type where the car is run solely on a cleaning solution to clean the injectors.
Have you looked carefully at all the vacuum hoses to make sure none are cracked. The ECM will often richen up the mixture to compensate for vacuum leaks.
When you changed the cap did you also replace the rotor? Both should be changed at the same time.
A faulty injector will typically cause a carbon-fouled plug, so pull the plugs and see if any look different than the others.
Change the PCV valve, as that can stick open, creating a vacuum leak.
Is the EGR valve fully seating?
Over time carbon build-up or just wear can cause the egr to not fully seat---which will be far more noticeable at idle.