[pthornton]

After starting the car it idles great and dashpot works correctly if I rev the engine, dropping back to dashpot of 0. But after driving the car and stopping, the car behaves different. The dashpot drops to 0 as when I rev it, but before it drops all the way to idle rpm the dashpot kicks back in. It gets in a loop on this at 1000 rpm. Idle actually is smooth, only see the loop in logging. Idle is set at 800. Before I start experimenting, any suggestions. This cam has been a pain with it's overlap.
Randy

[pthornton]

I've attached my current x3z based tune.

[decipha]

i always loved the look of them saleens

im on my tele so no help here

[cougarnut281]

On my phone also but what is the tps and throttle status doing?

[pthornton]

Don't have my tuning computer with me, I'll post a datalog Monday.

[pthornton]

Well, I was finally able to catch it while datalogging. My TPS jumps from .78 to .86 volts when I'm not touching the throttle. This puts it in part throttle mode and causing it to idle up and stay there. First off is .78 normal for idle? Should a change this small put it in part throttle mode? I guess this probably means I need a new throttle position sensor?

Randy

[pthornton]

If I change the DELTA breakpoint for part throttle to .10 it should help, but is this too large and tuning around a bad TPS sensor?
Randy

[EDS50]

If I change the DELTA breakpoint for part throttle to .10 it should help, but is this too large and tuning around a bad TPS sensor?
Randy

Sounds like the tps could be shot. Worth a try replacing it since its cheap enough. If it still happens with the new tps I would start looking at the ecm.

[pthornton]

New TPS is holding steady at 0.98 volts. Amazing how much a bad part can mess with your idle, thought the cam was causing the surging.
Randy

[EDS50]

Glad it turned out to be a simple fix.