1995 Chevy WT 4.3 RPM's don't come down

[IBelieveinlube]

Just bought a 1995 Chevy WT w/4.3 V-6, 5 speed. 154,000 on the clock. Uses very little oil. One odd trait - when shifting gears, the RPM's come down very slowly. Also, sometimes RPM's go up a couple of hundred when clutch is pushed in and then settles down to appropriate idle of about 600 RPM. Some sort of sensor need replacing? Anybody have an idea - might want to try to fix before I take in to mechanic.

 

[javacontour]

If it's anything like some Ford's I've owned, the RPM's are held up as part of the emissions control strategy. I guess there is some difficulty in controlling emissions when the throttle snaps shut, so the Idle Air Control is held open and slowly closed to help mitigate the issue.

I'd not worry about it, it's probably part of the emissions control strategy.

 

[MrCritical]

Perfectly normal. You might clean the throttle body and get a little quicker response, but expect minimal results.

 

[blackcherry06]

I drove one of these at the pipeyard I used to work at. They programmed it this way for emissions purposes, but you can smooth it out a bit by changing your shift timing. I started lifing throttle a little before pushing in the clutch and it helped with RPM climb, but it still liked to hold RPMs during the shift. Not much you can do about it, but it is normal.

 

[mechtech2]

You may have the odd problem of a bad neutral switch. This is also one of the switches on the clutch pedal. The lower one is for the starter lockout, the upper is the pedal position, which is the same circuit as the neutral switch.
Check it out.

Also, if your AC is on [it can go on in various positions], your idle will take a while to go down.

If your battery was replaced, or your computer reset, the idle will also come down slow for a while, until it relearns the parameters.