Help my funky idle....

[cavedweller3366]

This is driving me crazy. Have a '99 with a 2.4. Here's what I did to date: timing belt, water pump, plugs, l.o.f., wires, radiator flush, cap, and tested the coil pack , alternator, etc. No check engine light on, ever. Checked for codes anyway, and there were none. No smoke, no compression problems. Car is quick and strong. Unless it is idling!!! At idle (whether in park or in drive at a standstill), car's idle is very wierd. It is almost like a heartbeat. There is minimal fluctuation though in the rpms because tach is steady at about 750. It is as if the engine is loping to this patter, zzzzZ, zzzzZ, zzzzZ, zzzzZ.....and then every so often it breaks down to four rough idles and then continues this pattern until I accelerte. Any ideas guys/gals? Thanks for your help.

[dsramprat]

It is a possibility the timing belt might be a tooth or two off, but I would check that last. I know you said you are not getting any codes, but it might not hurt to chech the cam position sensor, crank position sensor, throttle position sensor, and idle air control motor. Another possibility could be the fuel filter, or the coil pack.

This one is a little confusing since your are not getting any codes. If I think of anything else, I will let you know.

[cavedweller3366]

Thanks for the quick reply...will check the above and post results.