Rough at Idle and low RPMs (99 SOHC)

[drewkeen]

My 99 SOHC has a rough idle and is also rough at low revs. At highway speeds it seems to smooth out and when you get it in it is a lot smoother. I have put new plugs, wires, air filter, fuel filer and a coil pack. None of these really made much of a difference. I believe it runs just as rough when it is warm as it does when it is cold leading me to believe it is not the intake manifold o-rings. Any ideas or suggestions on what to do would be greatly appreciated!

 

[Ranger379]

what about the Idle Air Control? mine ran fine, i replaced it and it ran ALOT better. well idled better, smoother back around 900rpm. or maybe the MAF?

 

[Creatve]

yeah mine does the same also. You can feel the car actually shake. hopefully you'll find out what it is so i can fix mine hah

 

[drewkeen]

yeah mine does the same also. You can feel the car actually shake. hopefully you'll find out what it is so i can fix mine hah

Mine also shakes. It makes funny noises until around 2500rpm and then magically gets smooth. I bought a can of MAF cleaner today and plan to use it tomorrow. It doesn't feel like a bad IAC as it is more shaking then hunting for idle.

 

[Ranger379]

i read that u can test to see if your MAF and IAC are working correctly by idleing the truck, then unplug the MAF, if the truck suddelny runs like crap, your maf is OK, same with IAC, with the 95 you can unplug the maf and it actually runs better lol, so that it an easy test,but like i said my iac was working, but when i replaced it ran alot better