PDA

View Full Version : 91 ProStar: Engine Over Revving in Neutral


TonyB
05-26-2012, 09:16 PM
After a great day on the boat with friends I headed back to the launch to call it a day. When I approached the launch and reduced the throttle it would not come back to normal. In neutral it was over 2200 rpm. I backed the idle screw all the way out and that reduced the rpms to around 1500. I've looked at everything on my Holley 4160; I've checked and lubed the throttle linkage and every other moving part on the exterior of the carb. Still, it over revs.

Suggestions?

1redTA
05-26-2012, 09:26 PM
choke out of whack?

waterlogged882
05-26-2012, 09:29 PM
..........

Jerseydave
05-26-2012, 09:32 PM
After checking to make sure your throttle plates close all the way, start looking for a vacuum leak. Check all vacuum hoses including your PCV hose (if you have one)
You can also spray 2+2 around the intake gasket if you find no other vacuum leaks. If there is a vac leak the idle will increase when you spray near the leak.

waterlogged882
05-26-2012, 09:39 PM
..........

TonyB
05-26-2012, 09:49 PM
After checking to make sure your throttle plates close all the way, start looking for a vacuum leak. Check all vacuum hoses including your PCV hose (if you have one)
You can also spray 2+2 around the intake gasket if you find no other vacuum leaks. If there is a vac leak the idle will increase when you spray near the leak.

I've had vacuum leaks. They are only an issue at low idle rpms (i.e. rough idle). Once the rpms get above a certain level the amount of fuel overcomes any "vacuum" that may exist.

Ive Checked the springs, the plates, etc. Everything is going through its full range of motion. But the rpms remain unbearably high.

Boat had been running great all day. On the way home I did come out of the hole somewhat hot and then proceeded to the launch at around 35mph till stop.

Anything else?

waterlogged882
05-26-2012, 09:57 PM
..........

TonyB
05-29-2012, 10:24 AM
Inexplicably, all is back to normal.

Carry on.