Still can't fix it

[Runwithem513]

So I posted before that my 2007 3.0L merc has been idleing real rough, I tried a compression test
On it and all cylinders are at 135psi and that was done with engine warm. Next I checked to make sure file was getting to the carb alright an it was ten checked spark seemed alright. I then tried a timing check and the notch was frozen almost two inches above the timing fixture, is this normal? I tried adjusting it back down but it still ran like garbage. Any ideas maybe a new distributor rotor and cap is in order?

 

[Bt Doctur]

Re: Still can't fix it

firing order correct?

 

[Don S]

Re: Still can't fix it

About 90% of the time is because the idle mixture is too lean. Richen up the idle mixture, bet it starts better, runs better, and stops dieseling when you shut it off.

When you adjusted the timing, did you put it in base timing mode and bypass the shift interrupt switch as explained in the manual?

 

[Runwithem513]

Re: Still can't fix it

Put it in base timing , it's normally not hard to start just real rough idling not dieseling either. I've repeatedly tried to look up a diagram for the wires on the distributor and cannot find one, I haven't touched them but did have I tuned up before end of last season and winterized so I'm not sure if they put them on wrong or not ad like I said in my other posts I runs like a top at full throttle. Also I noticed just a little bit of oil on plugs one and four while checking compression any ideas

Thanks

 

[Don S]

Re: Still can't fix it

Well, it's sure not hard to find information on a 3.0L
Have a look at this file.

View attachment 3.0 EST timing.pdf

 

[Runwithem513]

Re: Still can't fix it

I've seen that sketch and looking at it it says that the bottom right is going to third cylinder but they put that on on mine to one, top right to cylinder two top left to cylinder four and bottom left to cylinder three does that make sense?

 

[Don S]

Re: Still can't fix it

First thing you need to do is forget about the diagram for a while.
You absolutely must find TDC on the Compression stroke That is easily done like this (Click Here)

Then remove the distributor cap and look at where the rotor is pointing and look at where it is in relation to the contact on the distributor cap. That is #1 spark plug wire terminal. The rest go in the proper order 1-3-4-2 in a clockwise direction on the cap.
Then, the firing order will be right. But you must get it on #1 TDC on the compression (not exhaust) stroke first or you are just wasting time.

A boat may be a toy, but it still takes mechanical abilities to understand and fix them.

 

[Runwithem513]

Re: Still can't fix it

Appreciate it Mr don ill try that tomorrow and work from there

 

[airshot]

Re: Still can't fix it

I have found on my 3.0 that I had to adjust the carb while in the water and underway. Had my son in law handle the boat in a long canal where we just idled along. I was able to adjust idle speed and fuel mixture much better than in the drive way on muffs.

Airshot

 

[Don S]

Re: Still can't fix it

I have found on my 3.0 that I had to adjust the carb while in the water and underway. Had my son in law handle the boat in a long canal where we just idled along. I was able to adjust idle speed and fuel mixture much better than in the drive way on muffs.

Airshot

While that is true, it can be adjusted in the drive way to find out how things will run, then head for the water for some final tweaking once it runs like it should.

 

[Runwithem513]

Re: Still can't fix it

I think I'm gonna check both out tomorrow depending on weather it's supposed to be raining and I don't want to mess around with the St. John's on a bad day lol it gets real hairy