engine vibration during idle

[98REDrang]

98 ranger 4.0 4x4
does anybody know what would cause or how to troubleshoot the engine that vibrates slightly every 2 seconds while idling? its a cyclic vibration not a constant vibration and not very strong.
Last year I replaced the TQ and upgraded the VB and now I'm due for a new battery (still on OG!); shocks; plug wires... and I'm worried that after 10 years of fairly good service she is going to become a money pit I also have a burning smell that I have yet to trace...


fixed/replaced so far:
radio;IAC;TQ;VB;calibers;windshield;thermostat;hub;heater control value.

 

[MustangP51]

If you have cleaned the MAF, IAC, and Throttle Body, and changed the plug wires then I would say that it is either; the coils, the spark plugs, or a vacuum leak.

 

[LMedina]

Aloha, I have the 4.0 OHC engine in my 2000 Explorer and as long as I've had it, there's been that cyclic vibration at idle, just as you described. My cousin has the exact same model and year and his engine also idles the same. From what I've read from third-party reviews of the time, this engine does not idle smoothly, and if yours once did, you were lucky. Despite all the maintenance, servicing and cleaning, this vibration has never gone away, never gotten worse, and I've never worried about this vibration on my Explorer. This is normal operation as far as I'm concerned.

 

[BLINEMOTORS]

I have 94 explorer with no power and abad vibaration we have changed
wires,plugs cam sensor,ma sensor idle speed motor any sugestions

 

[BLINEMOTORS]

I have 94 explorer with no power and abad vibaration we have changed
wires,plugs cam sensor,ma sensor idle speed motor any sugestions