Rough idle

[Ken Mikos]

1985 3.2 Cab with 46,000k
Replaced the Cap, Rotor, Wires, Plugs and O2 Sensor. Car runs 100% better but idle still hunts, not bad but not smooth.
Any suggestions ? Thanks again Ken

[proporsche]

when you say hunts..it goes up and down on idle..right..Does it only cold or even when warm?
Ivan

i would suggest adjusting the fuel mix---do you have an aircondition?

[Ken Mikos]

- rough idle is a better description than hunting idle
- it does have air but I haven’t used it

Leaning toward a Fuel Injection Idle Module or vacuum leak ?

[tmadden2]

Franny's video on the idle control valve can run you through some typical cold idle conditions, what vacuum lines do what, and how to clean the ICV.

https://youtu.be/MRZG-s_55CU

[Nick Triesch]

Tighten down all the head runner bolts. I bet some are loose. Easy thing to try. Helped me years ago. Loose bolts will make tough idle.

[proporsche]

it is possible but i doubt the intake manifold is loose..The engine has only 46K...miles
The reason i have asked for you air is.If you put the engine on and let it sit on idle put on your a/c.Then step on the gas and let it go back to idle if it dies or try to die your fuel mixture is too rich..
Ivan

yes, check as suggested into cleaning your idle control valve...since it is not hunting idle problem...

[Ken Mikos]

Thanks... How would I clean the Idle Control Valve, take it off and spray it with Carburetor Cleaner ?

[911obgyn]

Yep

[Nick Triesch]

Many different car makes used the same idle control valve. Find one at a salvage yard! I did.

[Ken Mikos]

Took off and cleaned the idle control valve which made no difference in the idle. Placed a hose on the housing and listened for movement, heard none.
- If i removed one of the hoses attached to the unit will would i see movement ?
- Does the unit work all the time ?
- Any suggestions on how i can test the valve ?
- If it needs replaced, do i buy a used or look for a new unit?
Thanks

[proporsche]

Ken put your ignition on(do not start the engine) go and put you hand on the idle c.v. it should purr like a kitten -humming---if it does it works..
Ivan

[Ken Mikos]

It’s not... Thanks

[proporsche]

i suppose you have it plugged in , the el. connector ,right?

[Ken Mikos]

Yes... What unit would you suggest i replace it with new, used, Bosch $$$, after market?

[proporsche]

it is all up to you ..i`d if you can get good used-tested -..they do not go bad that often..
Ivan

[stlrj]

Originally Posted by Ken Mikos

- rough idle is a better description than hunting idle
- it does have air but I haven’t used it

Leaning toward a Fuel Injection Idle Module or vacuum leak ?

Might check your firing order again since you did replace your cap. You won't believe how many times I crossed my wires up as careful as I tried.

[911obgyn]

I have screwed up my plug wires and it’s usually pretty obvious backfiring out of both ends!!

[Ken Mikos]

Took the unit off again for anther cleaning and tap (banging). Reinstalled and to my surprise its now working. Buzzing like a bee and the idle is smooth,
Thanks for all the suggestions.

[proporsche]

great ..congrats..isn`t great to be persistent;-)

Ivan