Re: why do blower engines surge at idle?
 

When an EFI does this it is caused by poor ECM control over higher flow rate of the injectors commonly used in racing applications. When this happens the IAC attempts to do it's job causing the engine surge like the one Cord describes in the Sorcerer. (turn your speakers up) A proper running EFI engine may do this only after a reprogram or reset.

A carb engine's cause for doing this could be anything. But who cares because carburetors suck :D

Roby

Re: why do blower engines surge at idle?
 

might want to have it checked out. The ECM may be losing power when ever you turn the key off. If this is the case it will surge on start up to warm up. If it is surging while at operating temperature then you likely have an IAC malfunction but this should turn on the check engine light.

Roby

Re: why do blower engines surge at idle?
 

As stated above normally the "Surge" "Lope" "Roll" or what ever you want to call it is from the carburetor, or ECM being out of adjustment. The Solenoid that Sterling, and some others use is designed to Raise the Idle RPM to a higher level when putting the boat in gear. This may be needed if you're running a very low gear ratio in your drive, with a huge prop.
We actually had a guy try and return a set of carburetors we built because the idle was smooth, and not surging.

Re: why do blower engines surge at idle?
 

I love to hear it !!!!!Makes the hair stand up on the back of my neck!!! :p

Re: why do blower engines surge at idle?
 

It only surges after its warmed up and the check engine light does not come on so no codes show up. I believe it may be the fuel pump.

OK, back to boats.

Thanks
Roger

Re: why do blower engines surge at idle?
 

AMG Benz blower motor isn't boosting at idle. Blower is freewheeling, so it doesn't count.

Re: why do blower engines surge at idle?
 

And it probably has about 12 lbs of boost at idle :D



when we dynoed mine it ran smooth on the dyno. I put it in the boat it went to surging ,probably because of water temp.

I liked the surge. Always ran it alittle fat to be on the safe side but it did not burn your eyes at idle.just one # up on the rears.

The main reason, I needed it to surge so I could shift the bravo drive on the down cycle so it would not bang going in gear

Re: why do blower engines surge at idle?
 

Is it equiped with carbs?.... I don't think so........ :cool:

Re: why do blower engines surge at idle?
 

the cam duration has a major role in how much a blown motor will lope

Re: why do blower engines surge at idle?
 

If it's a small block, check the intake gaskets. They sag in the center.