Surging throttle

[Hellbound]

Hey,

First..98 K1500 swb with 305 and 4L60E, 35" tires. When cruisin at about 80kmh with rpms between 2200 and 2600 every now and then the throttle will surge by 1 or 2 hundred (3rd gear). When on the hwy at about 100kmh in the same rpm range (OD) the same thing will happen periodically. Jut started happening a couple of days ago out of the blue. Once I get above that rpm range the surging stops.

Any ideas or where to start?

Thanks

Mike

 

[twomanymontes]

It sounds like your torque convertor is kicking on and off. Next time you feel it happening maintain the cruise speed, with your left foot, apply just enough brake pressure to turn the brake lights on. If the surge goes away, that's whats happening. You can try adding friction additive to try to help it. It takes about a 100 miles for it to really kick in. But you might have a solenoid or the convertor is starting to fail.

 

[Hellbound]

Thanks, I will give that a shot and see what happens.

Mike

 

[Hellbound]

It sounds like your torque convertor is kicking on and off. Next time you feel it happening maintain the cruise speed, with your left foot, apply just enough brake pressure to turn the brake lights on. If the surge goes away, that's whats happening. You can try adding friction additive to try to help it. It takes about a 100 miles for it to really kick in. But you might have a solenoid or the convertor is starting to fail.

I did your test and it behaved as you predicted. I will add some lucas tranny additive. Any idea where to go from here with a fix?

 

[twomanymontes]

Other than trying a friction modifier, basically take it to a repritable transmission repair shop.