Hi Guys got a problem would like some input.

Engine idles rough, really rough to approximately 2500 RPM. Set crank at TDC "0", checked distributor, rotor approx 15 degrees advanced from #1 plug wire. What could make this happen and how do I fix it? Is it possible for timing chain to slip a tooth? The distributor is tight and has not been moved. Have checked Harmonic Balancer and there doesn't appear to be any separation or defects in rubber.

Need some input with this problem thanks.

Have replaced crank trigger, and most of the sensors just a couple of months along with plugs, wires, cap, and rotor.

Rocks

 

Look for vacuum leaks at the nipples on the manifold as shown below. The hoses are usually rotted. Intake manifold bolts might have worked loose also. Check both.

Wrong photo for your year. Oops. Anyway, with it idling, spray some throttle body cleaner alll around the intake to find vacuum leaks.

 

Thanks for the input we will check everything and let you know what the outcome is. Thanks again.

Rocks