05 200 Hpdi Idle Issue

[Tuna Devil]

Here It is. I ran the Boat tuna fishing. Let's say 180 miles with *****ing. On the way home we stopped to use the rest room. In gear at idle the port lopes from 600 rpm to 900 rpm. If I bump it up to 1300 it clears up and runs smooth. Running the rest of the way home it was smooth. When I was at the marina docking (same trip) at idle in gear it did it again. I changed the plugs. So after that We did a couple of Fluke trips and a couple of Bass trips and it ran fine. Then I did another Tuna trip about the same distance. On the way home same scenario it did it again. That was Friday. Yesterday I went Fluking and did not have any issues. Any thoughts?

Thanks in advance.

[boscoe99]

Sync and link that puppy.

[Tuna Devil]

It's fuel injected. I thought that was more for carbureted motors?

[Tuna Devil]

Throttle position sensor?

[Tuna Devil]

No code on the computer.

[greasyshaft]

Just buy a service manual and do as it says. Any engine with multiple throttle bodies requires syncing and linking.
The TPS will only throw a code if it is out of its specified parameters.

[rodbolt17]

couple that with the fact that motor eats plugs at speeds about 1100-1500 RPM and this is what you get.
once fouled they run and idle poorly.

[99yam40]

couple that with the fact that motor eats plugs at speeds about 1100-1500 RPM and this is what you get.
once fouled they run and idle poorly.

Sounds like the motor does not like to do all of that *****ing for tuna

[rodbolt17]

monitor the O2 sensor feedback, a dirty O2 sensor accelerates plug fouling below 1500 RPM.

[Tuna Devil]

Why would it act up only after long runs? Thank you guys for all the responses.

The motors love tuna. Or it love gas. One or the other.

[rodbolt17]

typically we don't see plug fouling on engines that don't *****.
that's why the bass boat guys never see issues the tuna and mackerel guys do.

[Tuna Devil]

You seem to pretty dialed in. Why only after long runs? If it is the o2 sensor, Is the oxygen sensor heating up and then failing? Or is more like wearing out issue. I am asking because I can't figure out why it only does it after long runs. I ran it today. It was flawless.

[99yam40]

Sounds like a long run out then lots of *****ing before the run back when it fails