rough idle after tune-up

[darkengineering]

(Not related to my other post)

I just bought a 98 b3000 w/the 3.0, 47,000miles, 5spd. This weekend I changed all the plugs to Autolite double platinums, installed a 180deg therm, did the intake hot water bypass, cleaned the MAF, cleaned the IAC, cleaned the throttle body, flushed the radiator, changed the belt, oil/filter, and powersteering fluid.

Before I did this, the truck idled fine (when it idled down, see other post), but now it feels like its missing at idle, very rough. The idle is about 900rpm, which seems a little high. The truck is very strong at everywhere but idle, the plugs really made a difference (.075" gap on 3 of them!!!).

I did not reset the computer after doing this, as I figured it re-learns everything on its own. It has been driven over 100miles since the tune-up, no change.

The check engine light is not on and I ran codes before the tune-up and all was well.

Any ideas? Thanks

[Rockledge]

Boy, sounds like you've been busy as a beaver!

Have to start with the easiest thing to try first, and that is to reset the computer. Just remove the cable from the negative battery post for about 15 minutes and then reconnect it. Then you have to drive around for a quite while so, like you said, the computer can re-learn everything. Keep in mind that the computer has to re-learn and store a whole table of values just with regard to idle alone, and that re-learning process takes place only while the motor is idling (with and w/o AC load). Point is, it takes more than a little bit of driving for your computer to completely figure out and remember how to best maintain idle.

Try it out, see what happens, and then can go from there.

[darkengineering]

Hey rock, the truck has been slowly getting better, especially in regards to the very high idle problem in the other post. I will reset the computer and see what happens tomorrow. From reading, it seems as though a little bit of a rough idle is to be expected from the 3.0's. I'll tinker some more and see what turns up.

Thanks

[jbabbler]

Also, might as well go ahead and clean the IAC and replace the fuel filter while you're in a fix-em-up mood. The fuel filter did wonders for my idle. The IAC can also be sticky and cause the idle to jump around.

Mine still has the famous "3.0 stumble" but it more than makes up for it with all of the pinging it does on acceleration .

Hey! at least she's consistent!

[saintthomas]

I had the same idle problem when I cleaned the MAF. It took about a week adn it cleared right up.