Power cycling?

Have any of you experienced this?

What would cause your truck to cycle power?

Here's what I'm experiencing. Sometimes my truck runs fine, with great acceleration and power through all gears and excellent power in overdrive. At other times, my truck drives as if were bogging down or holding back with slow acceleration and horrible power. It actually feels like someone hooked a trailer up to my truck. At certain times and at constant acceleration, I can actually feel my truck correct itself and begin to run normally. At these times, it feels as if something in my eninge cycled or kicked in causing it to run better.

Is there a sensor or valve somewhere that I need to check?


1998 Chevy K-1500 Z71
126,000 miles
V8 5.7-L 350 Vortec
Firefighter Red

you said, "At certain times and at constant acceleration" did you mean: At certain times "while" at constant acceleration?

The reason I ask is that a buddy of mine experienced similar symptoms with his car. On his car, It was the torque converter locking up too early and it was like taking off in overdrive instead of 1st gear. It didn't happen all the time though. Does that sound like your problem?

Yes, it is similar. However, the transmission does travel through all of the gears. Do you think the torgue converter is trying to lock in overdrive yet it makes it through all the gears? What is the fix on that?

His fix was a new tranny for about 2 grand. You might want to go to a transmission shop to have them diagnose it. If that is your problem. I hope I am wrong.

Unplug the TCC solenoid connector while the truck is operating correctly. Drive it, and if the problem goes away, it is most likely just the solenoid.

J-Ri... I am not familiar with the TCC solenoid connector. Where is it located and what does it look like? Thanks.

Your best bet would be to get a repair manual for your year truck, but I'm sure someone who knows for sure will reply to your post asking that question. It would be near the front, where the clutch is. It will be a 2 or 3 wire connector. Sorry I can't tell you for sure where it is. I'll look on Shop Key and AllData tomorrow if I have time.

J-Ri, I have a manual, but what does TCC stand for?

Torque converter clutch, and unfortuneatley these transmissions (4L60E) have more than just the TCC on that plug. It is on the front of the drivers side of the tranny case.

Have you checked the fuel filter or changed it recently?

Yes, the fuel filter was changed 3,000 miles ago.

I have a little better diagnostics for all you out there. I discovered this today. When I was accelerating today out of a stop sign, the truck was holding back at first, then I actually felt something click in and then all of the sudden I had my horsepower and acceleration back. What "clicked"??? Could that have been a sensor or what?

My guess would be it was the TCC unlocking. The torque converter increases torque while accelerating. Now I would say the TCC is definately at fault.

J-Ri, What will it take to fix this? and Cost? Thanks for the help.