2005 350Mag MPI 300hp inboard Tritoon only hitting 4300 rpm!

[Yamanator]

Lol...
Is there a way to test the knock snsr?
I have a Techmate Pro scantool and on this boat with this ecu it is limited as to what it can do!! Just wondering if there is a way to test it as it would be a mutha to replace it on this thing!!!

[Motv18]

The knock sensor only throws a code if it fails ohm test, or on a two sensor system one reads less or more. An overachiever is just protecting the engine.

If if you knew the spark map you could try checking active timing.

Newer cars and such the ddt shows knock sensor read out. We use it to set max timing on custom tunes On whatever it works on boat or car.

Well I’ll might be time to get physical and hook a vacuum gauge to the intake and look for flutter. Ie bent pushrods or screwy valves. The should have shown in a leakdown but pushrods or lifter won’t.

[Yamanator]

We did the vacuum test more then once! No fluttering at all! I wasn't sure of myself when I did it on the lake but the last place I took it to double checked it and said its perfect!

[Capt.Insane-o]

Throw a timing tape on the balancer and watch the fun.

[Yamanator]

Throw a timing tape on the balancer and watch the fun.

I thought of doing that a long time ago but since there is no metal gauge to read it from how would you read it? Usually there is a gauge to read from bolted to the timing chain cover!!! Not on there, Mercruiser said its because it's an automatic adjusting system. I was told by another member on here you can read it with software while the motor is running. My scantool only gives me spark advance, not actual timing....:-(

[Capt.Insane-o]

TDC tool and a yellow paint pen dot. Slap the sticker on and go.

[KIRCHNER]

TDC tool and a yellow paint pen dot. Slap the sticker on and go.

JUST manually give it some advance. see if any rpm gain. agree tdc mark with timin light.

[Capt.Insane-o]

JUST manually give it some advance. see if any rpm gain. agree tdc mark with timin light.

That doesn't work with that management. Junk in, junk out.

[Capt.Insane-o]

Anyhoo...motor ran as advertised...motor ate a distributor gear...was repaired..hasn't run right since. Probably not the tab washer on the propeller, or the gear lube was changed on a Tuesday instead of Thursday or the knuetanic poopulator solenoid backfired.

350 chevys aren't terribly tough to fix

[Motv18]

Just curious what caused the iac change. And did it fix anything.

I know we’re talking high end operations but low end operating issues just get bigger or go away up top.

[Yamanator]

Just curious what caused the iac change. And did it fix anything.

I know we’re talking high end operations but low end operating issues just get bigger or go away up top.

I was getting a slight popping out the throttle body so I just decided to change that out and the little muffler thing inside. It did seem to help a bit but still had the popping! From what I'm being told by the last place that had it the popping is gone, the beeping is gone, and from idle speed to wot it runs as smooth as silk!!! Just won't get to 5000 rpm...😥 I really don't want to sell this boat as we love it and its paid for, but I'm seriously thinking if it can't get fixed I might have to off it.

[Motv18]

Iirc it runs on a cam sensor. If as you suspect the cam jumped a tooth. Timing will never be set right with the scanner.

Either do the tdc test test or pull the timing cover to check.

Gurus could look look at the distributors position and probably tell if something wasn’t lined up right.

That would basically end the simple stuff. Other then tapping the map to check for a broken board.

[Yamanator]

Iirc it runs on a cam sensor. If as you suspect the cam jumped a tooth. Timing will never be set right with the scanner.

Either do the tdc test test or pull the timing cover to check.

Gurus could look look at the distributors position and probably tell if something wasn’t lined up right.

That would basically end the simple stuff. Other then tapping the map to check for a broken board.

Original map sensor was put back in when the original distributor was put in. They said it cleared up the beeping and the popping coming out the throttle body.
Weather here is starting to turn warm and I want to get a jumpstart on this thing. I have some mechanic friends telling me I should spend the money and have the original injectors sent out to be flow tested and refurbished to new!!! I put brand new injectors in it I bought from a company in Cali. My friends are saying that you never know what your getting though so I should go back to OEM! Let me here your thoughts guys.

[flabum1017]

Timing gear got warn down bad on the teeth and finally gave out! I understand it could be from cam walk! Gear on cam still looks new.

Woner if the metal form the gear got into the lifter rollers and wore down the cam..... try checking the cam lobes for wear if you ever pull the intake.