95 Nissan pickup

I have a 95 Nissan pickup 3.0 4x4 this thing runs ruff not much power idols ok but when u put in gear it gets worse. It shifts kind hard to reves to like 4000 before it will shift. Idols about 800 and like 500 in gear

3.0 v6 4x4 vg30

On my 95 Nissan pickup, a bad Mass Air Flow sensor caused the engine to fall on its face.



Did u get a code when it went out only code I got is 55 no malfunction.
The shop said everything is pointing to computer ecm

No code. No Check Engine light.

But then, this vehicle is OBDI. Not OBDII


It sounds like there’s two problems, one is the engine performance, and the other is the transmission is slipping. I wouldn’t chalk either of those up to a bad computer as my first guess. For engine here’s where I would start. For the transmission, first get the engine working correctly and report back.

  • Basic tune-up, which means to replace fuel filter, air filter, spark plugs, distributor cap, rotor, and spark plug wires. then measure idle rpm and idle ignition timing, adjust to spec as required. those need to be spot on for an OBD I computer to work correctly.

If problem remains …

  • o-scope test of the ignition system
  • if that’s not possible, at least check for a healthy visible spark during cranking using a spare spark plug. briefly removing spark plug wires at idle can provide a clue if just one cylinder is misfiring.
  • check for vacuum leaks – unlikely to be the cause given that it idles ok, but worth a check
  • measure intake manifold vacuum at idle.
  • measure fuel pressure
  • check pcv and egr systems
  • valve clearances (if applicable)