IDLE SURGE AND DROP

[JASON739]

My 2002 20i with 350 mag. has a surge of about 1000 rpm for a few seconds and then drops to almost 0. If left untouched it usually recovers, but the natural response is to throttle up which can be dangerous. Anyone have same issue?

[stanley]

Do you have perfect pass? If so, make sure it's off. When on and not pulling someone throttle will surge and "look" for set speed

[JASON739]

No perfect pass option installed

[JASON739]

sudden rpm drop

I ran into another tige with the same problem today.
Has anyone had a sudden rpm drop that last 5 to 10 seconds and then recovers?
It only happens from idle speed to about 1100 rpms. It drops to about 300 to 400 rpms and even dies sometimes, but rarely. However, my son went out with friends in an '03 this weekend that has the same problem. Unfortunately, their boat decided to die as they came into the dock and got a nice gash in the gel coat.

[PColucci]

Yeah,
I've also had this problem recently. I wish someone would post a reply and shed some light on what it might be due to.

[flackpack]

I had a problem similiar to this. I don't have the Mercruiser engine, but my Marine Power engine's issue was very similiar. The engine would stay at a higher rpm after we were riding and when we would bring the throttle back to idle speed. After about 5-10 seconds it would finally roll back down to normal idle speed. Marine Power knew about this and sent me a new ECM (engine control module) and a Fuel flow control. I pulled out the old parts and placed in the new in about 15 minutes (Thanks to Tige MD's clear and easy directions). My boat has never run better! The only issue is when I go in for service, my ECM has a different (lower) amount of hours showing up in the computer.

Marine Power was good about getting me the fix right away and Tige' Watersports was even better at helping me resolve this issue. Push Mercruiser to sheck your issues immediately, losing power could be an issue when you are putting the boat on the trailer or docking!

[Tige M.D.]

there has been other posts similar to what you are talking about. we have a boat in here as we speak that has a little hick-up just as you leave the idle position. some boats are worse than others. this customer has had this problem since day one, mercruiser kept telling us that "it is what it is". wrong answere! the customer became such a squeeky wheel that merc reprogrammed their ecm and we are going to lake test it on tuesday.

call your dealer, call mercruiser 405/743-6555, and complain like hell. they will step up.