98 gmc 5.7

[tomyc]

my problem is that when driving at speed (30 mph and above) when I lift off of the gas pedal, it will not "kick down" just keeps on going at the same speed and rpm. Eventually it will slow down. Gas pedal is not stuck. Truck is fine at idel 600-800 rpm, and smooth. Any suggestions will help. Thanks.

[ratlover]

I had a 97 that costed for quite awhile, you sure its not that or is definatly it under power?

[tomyc]

ratlover, seems like its costing,not under power,I just started to notice this last week,has not done this in the past.

[wyldman]

Could the TCC (torque convertor clutch) be sticking ? or staying engaged ? It will keep the RPM's up as if the throttle is sticking.

A vacuum leak will also cause the idle to stay up.

Your best bet would be to get it scanned for codes,and have them look at the data stream for anything funny.You will be able to look at fuel trims,TCC data,and other stuff to help diagnose the problem.

[tomyc]

wyldman,
thanks, i did check the vacum lines, they seem to be ok, looks like I need to get it scanned. thanks for the advice

[SIPLOWGUY]

Try resting your foot on the brake to isolate and unlock the TCC.

[thesnoman]

I am thinking a vacum leak or a problem with the device that slows return to idle for emision reasons

[SIPLOWGUY]

Try cleaning all your throttle pivot points too.