Mr1 intermittent cylinder drop.

[Brandon_SC]

https://jetboaters.net/threads/one-engine-running-4k-rpms-lower.9897/post-319159

There is a photo that @Scottintexas posted showing ohm values for the injectors. Post #31 perhaps this can help troubleshoot?

 

[bronze_10]

I'm not taking out injectors! The ecu I can handle but I know nothing about injectors.

 

[Beachbummer]

The throttle bodies come out whole, and then you can work on the bench. They can be seen easily when you remove the air filter cover on mine, but there is quite a bit that needs to come off to get hands on them.

 

[Gym]

You may have to get home on one engine. Do you have tow valves or clamps to clamp off the affected motor? I'm wondering if you can then run a can of Seafoam through there. Could be some junk interferring with the spray pattern. Should be able to get Seafoam in any Walmart.

 

[Gym]

Well... that didnt fix it.. still down one cylender. I brought my yds software and performed some tests... its definately the number one cylinder .. but I think it is an injector.. when doing the stationary injector test fire there is no sound from injector one.... anything I can do while I am sitting on the water with the yds in my lap?

@HELP

Just thought of something...You said when trying to fire the injector using the yds you hear nothing. This indicates an electrical issue between the ecu and the injector. I'm not sure what the harness looks like between the ecu and the injector but you may want to open and inspect any connectors between them for corrosion or broken wires.

 

[Beachbummer]

the 4 brown injectors can be seen in the picture attached. The black metal mesh boots over the intakes are removed in the picture.

 

[bronze_10]

the 4 brown injectors can be seen in the picture attached. The black metal mesh boots over the intakes are removed in the picture.

Ok. I see the injectors but where is the electrical connectors to test the injector?

 

[Beachbummer]

I think it's underneath. Picture below. The big black covers come off with the large allen bolts.

 

[bronze_10]

Copy... its 102 degrees outside... when it cools off some I am gonna go out and see what I caN do!

 

[Scottintexas]

 

[bronze_10]

Ok... I have a confession to make. I never learned how to use a multimeter. there are so many symbols I never know which one to use.

 

[Scottintexas]

Ok... I have a confession to make. I never learned how to use a multimeter. there are so many symbols I never know which one to use.

I agree, way to many symbols, I use the more basic,
1. nothing noticeable
2. makes me tingle
3. makes me holler
4. knocks me off the ladder
5. makes me wonder what happened to the last 10 minutes

 

[Brandon_SC]

This is a decent video showing you how to use a multimeter to measure ohms.

 

[bronze_10]

I dont know how in the hell I'm gonna get to that plug.. is there no other way to test the connector at a different location?

j9

 

[Weeb]

It will stay... it will grab the first thread but once its hand tight it skips out of it. So I just turned it to the point just before it skips. Cant put a wrench on it but it will stay and if the only thing it does it hold the coil boot on then it is good. In my mind I was making it more complicated than it was thinking maybe that was a ground for the coil or something.

I had the same thing on my truck starter for years the last time I changed the starter I ran a thread chaser through it and it tightened Dow properly after that.

 

[Beachbummer]

I dont know how in the hell I'm gonna get to that plug.. is there no other way to test the connector at a different location?...

Man, that is tight.

 

[Mainah]

@bronze_10 injectors can test fine but also be clogged, stuck, or worn. My recommendation would be removing the fuel rail, remove two injector plugs, swap injectors, reinstall everything, then see if the problem follows the injector or stays at the same cylinder. Oh yeah were mechanix gloves with the knuckle protection as that looks like a knuckle busting area. Also get the torque specs for reinstall of any fasteners. Alternatively just buy and replace one injector so you don’t have to tear it back down again.

 

[bronze_10]

The yds I have has the injector failing. It will not activate. I am not comfortable removing the fuel rail and all that... I have never done it. I would like to find a way to test the injector either at the injector or somewhere down the electrical connection to see if it is bad or not. If it turns out to be the ecu then I can replace that easily.

 

[bronze_10]

Anyone have a digital copy of the 2008 service manual?

 

[Beachbummer]

Minute 5 to 11 has the good stuff...

So far nobody's ECU has failed open (cannot trigger the injector) so far everyone has failed with the injector receiving 12v...so it's likely to be the injector and not the ECU.

Can you PM me your email? I can send you something out of band. may or may not be the manual..plausible deniability and all.