Slight rough idle
 

hey people, might just be me being paranoid, which isnt uncommon, but I have a good sense for these things.

Seems as though im getting a slight rough idle, and very slight shaking that you feel in your butt at idle. Also seems to be a worse in park than in gear. when driving it runs fine.

Also another thing that i think may be related is that when you rev it up to say 3k rpm in park, when the rpm drops back down it goes under 500 rpm, lights slightly dim and feels like it wants to almost die, but then jumps back up to 6 or 700rpm.

yes, another thing i think may be related, i was sitting in front of a store last night, truck warmed up, over a 1/4 on the gauge (around -30C outside) and the truck started gaining rpm's by itself, only 2 or 300 and out of nowhere started idling at 900rpm. just though id mention that.

my 1st idea is the idle air control valve, which is what i hope it is. although when i cleaned the throttle blade maybe 4 months ago, it wasent bad at all (the throttle blade) not like the pics i see of others with black throttle blades. makes me think the IAC valve cant be much worse than my blade was.

but anyway, think these are symptoms of a carb'd up egr/iac?

just got some injector cleaner in there, will see if it helps.

I'm not sure that I would worry too much about what you are experiencing. A very slight rough idle, while not ideal, isn't something I would go digging into. If you really want to, you could clean the items mentioned as preventative maintenance...

i think i may, just for something to do. is there a gasket for the iac valve or just the o-ring?

i seen in one of your posts that you recommend taking the entire throttle body off to clean it, is this for the purpose of a more thorough cleaning? or can i get good results just popping the valve off and spraying it? is basic carb cleaner ok if it says oxygen sensor safe? thanks for the quick reply.

O-ring seal on the IAC valve.

You will need a new gasket for the EGR valve though if you pull that. Get the one that has an integrated screen.

I have always removed the whole throttle body just for ease of cleaning and so I don't drop something down into the intake. The throttle body base seal is an o-ring type seal as well.

thanks. is this cleaner ok to use on it? or would i be taking a chance

What cleaner are you working with?

motomaster "oxygen sensor safe" carb cleaner that states it lubricates moving parts

That should work.

ok, well i took my intake tubing off yesterday and i see 2 devices plugged into the TB, which one is the IAC? closest to firewall or radiator?

im going to wait till I get the egr gasket and do both at once. but it looks like you need to take the upper rad hose off the t-stat to get a screwdriver in there, and also is it a T15?

So far ive ran about 2 tanks of gas with cleaner, cleaned the TB (again) took the MAF sensor out and it looked great, repaired a torn gasket on air filter and I still have a little engine shutter at idle.

Ive also puttied up a small hole in the ypipe of exhaust and i havent heard a tick yet, fingers crossed.

So I take it if cleaning the IAC and EGR dosent fix the rough/shutter-y, idle I should check my spark plugs and wires? they are about 4 year old delco platinums with around 100,000kms and neihoff or whatever wires. never touched cap/rotor and such.

I cleaned the IAC, got it off and back on without taking the rad hose off, just made the job a pita. not sure if it cured my problem yet, havent driven it much. but it is the one closest to the firewall, looking at it made it obvious :p

going to try do the egr today.