# Rough Idle



## xIsaac2011 (Jul 14, 2013)

1993 Nissan Altima GXE

Problems 

-Bad Mileage
-Engine Stalls while idling
-Fuel smell in car at times, but not constant
-Car has wild idle speeds, sometime really low and it fluctuates up and down a lot, will turn off when Im not stepping on the gas at times. NOT CONSISTENT AT ALL.

Spark plugs didnt look bad when I took them out, they looked like normal used ones but the rotor was blown to bits when I took the distributor cap off; it fell apart right then. 

Since I replaced all these parts, my acceleration has been off the charts (much better than its ever been), but sometimes when I stop hitting the gas, or when Im just sitting at a light for a while or warming the engine up to operating temp, the idle speed goes from 800-0, stalling me in the middle of the road. The car turns on then right back off unless I rev the engine in N then shift to D. Check engine light will come on and off randomly, not necessarily when I stall. I wonder if Im running in fail-safe mode? Heard it but not sure what it is.

SOMETIMES IT WONT TURN ON IN PARK AFTER THE STALL; HAVE TO START IN NEUTRAL!

ECM gives me code 34, which Hayne's Manual says is knock sensor. I have suspicions about the MAF Sensor, and the O2 Sensor as well. Any one else got some ideas? This one has me scratching my head.

Looking into getting a multimeter to test a few sensors...but any other ideas besides this? My cars been out of use for a month now and I have money to take it to a mechanic.

Things I have replaced in the last year

-Spark plugs and wires
-Distributor Cap and Rotor
-Air Filter
-Fuel Filter
-Alternator
-Gaskets


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## smj999smj (Jan 1, 2006)

Fail safe model lets the engine idle and run fine, but limits the RPM to 2500 RPM, at which point it will surge violently. It doesn't sound like you're in fail safe. My first thought would be a leaking intake manifold gasket; these are fairly common on the the U13 Altima KA24DE engines. Try spraying carb cleaner around the intake manifold gasket area and see if the RPM changes; if so, that's likely you're problem. Also check your EGR valve for sticking; I have seen in the past where pieces of slag from the exhaust have been sucked-in under the EGR seat, keeping it open.


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## xIsaac2011 (Jul 14, 2013)

Where should I spray? Im not familiar with the intake manifold gasket area. I can get you a picture of my engine and maybe you could help me out here? Thanks for the reply.


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## smj999smj (Jan 1, 2006)

Spray where the intake manifold bolts to the cylinder head. Refer part code "14035" in the part diagram linked below:

Part Detail


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## Asleep (Jan 19, 2003)

When you pulled the rotor, did you look under the cover there? Sounds like you may have oil in your distributor on your exciter plate. Also, a very bad pcv valve will cause problems like you describe. They're a real bear to get to on these engines though...


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