# Extremely Rough Idle



## rogerdl (May 23, 2007)

I apologize in advance for the length of this post, but I want to give as much background info as possible.

I bought a 1993 Altima (with KA24DE engine and auto trans.) which had a broken upper timing chain and had set for about a year. The repairs I’ve done to date are: all new timing parts, replaced head and valve train, new oil and water pumps, new rotor button, distributor cap, new spark plugs and wires, new head gasket and valve cover gasket sets, new PCV valve and hose, new fuel filter and I replaced all try rotted vacuum hoses. I thoroughly cleaned the intake and exhaust manifolds, piston tops and cylinder walls with SeaFoam. I set the timing to 20 degrees off TDC per the manual.

The problem is that the engine idles extremely rough and dies sometimes while idling. The car runs great off idle (over 1500 rpm), with good acceleration and plenty of power.
I’ve swept the engine 3 times for vacuum leaks, once with carb cleaner and twice with propane. I found no vacuum leaks. I removed and cleaned the Idle Air Controller, the Fuel Rail, the Throttle Body and the EGR valve. I tested the Mass Air Flow Sensor and it works fine. I filled the tank with 93 octane gas and added injector cleaner and gas treatment. Nothing has worked. The check engine light has not come on. The only thing left I can think of is to run a live scan of the engine and check the waveforms against the FSM to try to find the problem.

Does anybody have any other ideas that I can try? I'm totally stumped!!


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## LONDONDERRY (May 19, 2004)

If I had a dime for everytime I heard this issues I could quit my day job. Wnat to bet your distributor is bad. Remove it and if you see any oil inside replace it. $250-550 part cost. search on this thread for distributor and you'll see what I mean, very common problem

Frank


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