Keytime

My guess... loose nut behind the wheel.

BUP

iTrader: (9)

I still would verify rpms with a digital tach and or scan.

buck183

I think my boat has the same problem.

bigboat28

IAC sensor maybe, 2004 Formula 6.2s did the same thing would idle but dye going into gear but it also had the warning beep going off. When they first went bad they use to go out really, close to each other hour wise.

phughes69

[ATTACH=CONFIG]540232[/ATTACH]I still think the IAC motors are not connected. From the picture it looks like the connection for the IAC motors is under the intake. It would be easy to forget to connect it. (I know, I have forgot to attache it on my Vette when taking the TB off). The other thing Nova26 is did the shop that did the work remove the throttle bodies? Im not sure about these throttle bodies but I think the gaskets between the throttle boy and intake have to go on a certain way to allow the air passages to line up correctly. Not 100% that is the case, but I remember that from my days of working on the old TPI Vettes and Camaro's Firebirds

Knot 4 Me

Advance throttles to 3,000 RPM and then shift. Report back! Sorry, just remembering my buddies back in the 70's with wimpy cars that wanted to do burnouts. Neutral drop!

BUP

iTrader: (9)

Could be anything from TPS to IAC in which both are installed at the throttle body. Throttle linkage and or throttle cable - worn or adjustment off.. I would look into a scan to see voltage at the TPS within spec and IAC counts - 0 thru 40 - Throttle blade position also is determining factor for the IAC pintle position and counts.

BUP

iTrader: (9)

Forgot the TPS is installed on the bottom in conjunction with the throttle linkage and the IAC is installed upper back side of the throttle body itself. Not that hard to see if they are connected.

What is your idle quality and starting the engines like. Hard starts and very poor idle can be linked to IAC. Poster never mentioned any of this. So ???? mark - how is starting and idle quality ?

nova26

I did notice it was a little harder starting they normally start right up. They do not light off as soon as you hit the key now. But I can't say it was bad. Idles smooth. I'm going to put some fresh gas and run it in the morning before dropping it off tomorrow. I really don't think the gas will make a difference I ran it into November last year with 91oct.

BUP

iTrader: (9)

Will your engines accelerate in throttle only (not shifting into gear ) ???

Adding some info for whomever and a simple try for yourself. .

RVP of the gas blend itself. Its a big deal for boats. RVP has different blends in the spring, summer, fall and winter gas. It ranges in values from 7 to 13 + depending what part of the country and whether conditions that take place during.

I would take a portable outboard gas tank and new fuel line with current fresh gas - hook to inlet fuel engine side and the run the engines to see if anything changes. I say all the time you have to separate which side of the boat is the problem child.

RVP = Reid vapor pressure - google it, everyone just might learn something. It is highly taught in OEM Marine schools for the past 35 years. THE JIST - Winter gas blends do not lite off in hotter months and summer gas blends does not lite off very well in cold winter months. This is very common in my neck of the woods.


Also just went thru this last week - and every year from winterization time to spring commission - boat hard to start along with not so great ide - accelerate throttles - engine dies imnediately. Run motor on my shop portable gas tank and fresh gas - taking his fuel and tank out of the mix - motor runs great - throttles very well, sample his gas from his gas tank - looks perfect - no water (NONE) plus, I winterized the boat in DEC 100% properly and the complete fuel system.. Customer bought gas in DEC the day he brought me the boat. Its 85 degrees out now. Has nothing to do with E-10 and all to do with RVP blend value of the gas itself. Just saying because if you are not taught this whether it applies to you or not - it will someday, especially if you own a boat.

This is a broad post for everyone - and worth a try but I am not saying this is your 100 % problem. I see it a lot here because of our huge temp swings and gas blends that change at the pumps during different times of the year. it causes minor to poor to very poor engine starting and running conditions.

If you work on boats - A Portable fuel tank with a quality fuel line and primer bulb using fresh gas is a another tool in your tool box. I promise - it is a great tool for testing and problem solving.

Ok the story book is finished now. I have to go crawl back into engine compartments myself. Good luck