Hi I have a 1990 Nissan Bluebird U12 sr18di.For a month it has had rough idling and now it does not go at all.The engine starts, rough idle and cuts out in less than a minute. If I give it gas, it does a blowback fire and cuts out straight away.One mechanic tested all the plug leads and said there is spark through them. I have changed the spark plugs, ignition coil and airflow meter so far.The distributor was changed two years back. I have checked that fuel does come through and fuel filter was changed last year. Help !!!

SOURCE: Very Rough Idle and sometimes cuts off while idling

sounds like bad Idle Air control valve Not Cheap

SOURCE: My 2003 subaru forester idle very rough. if you

1) Check all the vacuum hoses for a leak in the rubber hose or a hose that isn't connected. Vacuum leaks cause motors to shake and stumble on acceleration.
2) There's a plastic T connection on the back side of the engine behind and under the air cleaner box. That T connector joins together three air hoses of different sizes and is prone to breaking from heat stress. Only a Subaru dealer will have this part.
3) Even though the spark plug wires are new, you may have a bad one. Don't waste your money on cheap parts; they cost more in the long run.
Good luck!

Steve Hurc

• 459 Answers
• Posted on Jul 20, 2009

SOURCE: 2000 Daewoo Lanos intermittently idles rough

check throttle body and pcv hoses and ports for blockage possible carbon build up and sticky iac valve

SOURCE: Nissan b14 rough idle, black smoke

i have a nissan b-14 idle roughly sometimes cut off when in traffic. any solutions???????

SOURCE: 1996 Honda Accord Rough Idle Even After tune up

Perform a valve clearance inspection and adjust if necessary. Tight or sticking valves will cause a misfire or rough running concern. Note: Perform valve adjustment when the engine is stone cold. 4cyl: INT 0.26mm EXH: 0.30mm (V6 engine are hydraulic and no adjust necessary.) Also check for a sticking or stuck open EGR valve. For diagnostic purposes only: Remove the EGR valve. Place a business card over the EGR passage and bolt the EGR valve back on. This plugs the EGR ports and if the misfire goes away the EGR valve is partially stuck open and is defective.
Check for low fuel pressure. Check for low compression. Check cam timing. Check for a weak ignition coil. Also don't over look the possibility of worn or broken engine mounts which cause excessive engine movement and engine vibration. -hope this helps