DF300 no start

[TJHaleen]

I’m looking for a little help figuring out what is wrong with a 2007 df300. I bought a used boat (Pro Kat catamaran) that needs a little work. When I was getting it ready for the water, I ran the starboard motor on a hose. It started fine, ran good, shifted in and out of gear, everything seemed good. The port motor would not turn over. The starter looked old and rough so I took the starter out of the starboard motor and tried it in the port. That didn’t help. After a lot of messing around with it i found the ground cable was no good. I ordered a new starter anyway and when i came back to work on it I put the ground cable in it and it started right up. I then took the new starter and put it into the starboard motor. When I was done I tried starting the starboard motor again but it would not start. It cranks over fine, but no start. I have been trouble shooting this problem for awhile now and I can’t figure it out. It cranks fine, there is good fuel pressure, there is good spark, all injectors are firing but yet it won’t start. It won’t even start when I spray starting fluid into intake. Nothing. I can only assume it must be something electrical. I have been replacing battery cables, new batteries, I put a new wiring harness on the engine. I think I’m chasing an electrical gremlin but could use any help I can get. Thanks!

[briscoe]

It is not possible to spray ether into engine, crank and have fire on the plugs, without it trying to start. If your injectors are spraying fuel the issue has to be no fire at the plug. If you have fire at the plugs and no start its fuel. Unless, you jumped time, which is hard to believe. I'm not a 300 expert but this sounds too crazy.

[TJHaleen]

I put a fuel pressure gauge inline and it reads about 42. I also cracked the fuel rail while cranking and fuel sprays everywhere. I pulled out each spark plug and watched the spark come off it while cranking with them near the block. And I sprayed starting fluid into the intake side and cranked it and only got a puff of smoke. Someone else mentioned to me that it sounds like a timing issue. It was throwing a crank sensor code at one point during all this could that be related?

[redlowrey]

How do you know that the injectors are firing did you test them or are the plugs wet. If they are wet with fuel dry them and when you try to start it use the switch on the dash to manually open the throttle.
I am assuming you have a throttle cable not electronic throttle control.
When you disconnected the battery the iac valve may not be bypassing enough air on crank from memory loss and is flooding.
Come back on the forum and tell if the plugs are wet or dry if it don’t start.

[TJHaleen]

Tested the injectors with plug in test lights they show sing all is coming into the injectors. Plugs are dry. No cables all flyby wire.

[redlowrey]

Ok forget about what I said about the iac with electronic throttle control when you turn the key on the computer should open the throttle to around 18 % of throttle control for starting.

Do you hear anything at the throttle when the key is turned on, you might even hear a humming sound.
With the key on check the voltage at the temp sensor and exhaust temp sensor unless you are in the Arctic you should see around 3 volts if the voltage is around 1 volt the ecu will not be injecting enough cold start fuel.

Seems strange the only thing you done was change the starter.

[TJHaleen]

I have a manual but I’m having trouble finding the two sensors. In the ECM if have ex-manifold temp sensor #1 it reads just over 4v, where is the other one?

[TJHaleen]

Cylinder temp sensor is 2.3V

[briscoe]

TJ you mentioned testing the injectors, signal to them. You also pulled them out and the ends are clean? I plugged up my injectors one time and I could see the crud plugging the screen-like end. You indicated the spark plugs are dry. Just saying. Also, I would not expect ether to have enough fuel to start a 300. That ran through my mind early thread. If ether got smoke, then why doesn't gas get something?

You have RedLowery helping now, he's is an electrical wizard.
Good luck bud

[briscoe]

I see your online reading post. Don't you agree?

[briscoe]

One other thing, TJ. Why not try and put a few CC'S of gasoline in each plug. There should be something to place a measured amount into them. I have these plastic syringes. Pretty sure a CC wouldn't be to volatile

[redlowrey]

Unless you are in a very cold area like nearly freezing to have sensor voltage over 4 volts is too high it should be closer to the temp sensor voltage.
It is very hard trying to diagnose problems with electronic throttle control over the internet because I have no idea of what position your throttle is at that is why I asked you if you could hear anything when you turned the key on.

It seems strange that you had no problem starting the engine before you changed the starter, anyway I am sure that engine has l temp sensor
and one exhaust temp sensor for each head.

You did not say whether you could hear anything at the throttle when you turn the key on if the throttle is not opening enough and with that very high sensor voltage it will never start.
pull the cover and see if it opens a small amount when you turn the key on and crank.

If it is opening pull the connector off the temp sensor and the check engine light will come on but the computer will substitute a value for the sensor crank the engine and see if it starts.

[TJHaleen]

Thank you for your time and help. It turns out that the brand new starter was the culprit all along. I switched out the starters and put the old one back in and it cranks much faster and started right away. Crazy!!

[redlowrey]

If you had of said that it cranked a lot slower than before it would have created a bit different direction, good you have it fixed.

[briscoe]

OMG. If you did one thing and things turn bad, go back and reverse it. RedL it was good you kept mentioning the starter as the only thing replaced.