2005 F250 Running Rough

[res1xhxc]

I have had a multitude of problems after a June 2011 lightning strike. Ignition knocked out, Tacs dead, ECU's messed up and engine running rough. All the afore mentioned have been corrected except rough engine.

Technician diagnosed bad coils on cylinders 5 & 6, replaced coils but engine still running rough. Anyone have any ideas/suggestions?

[boats.net]

With lightning any thing could be bad, did they run diagnostic with computer to run checks on all sensors? If not that would be the best place to start.

[res1xhxc]

Thanks boats.net. I am still in the process and read in the Yamaha shop Manuel that the crank and cam position sensors could be in the mix. The technician is returning this week to test those.
This has been a real nightmare for me I have sympathy for anyone that has had to dal with this problem. I'm hanging tough and will win in the end.

[boats.net]

Usually have to test all sensors but with the computer diagnostic models it makes it a little easier(since you have already replaced ECU) but have to read data carefully to determine if working properly. Don't forget about wiring and grounds.

[res1xhxc]

F250 Running Rough

Thanks Boats.net, what are your thoughts on cam position sensor causing my problem? There are two (2) cylinders not with no/weak spark No 5 and 6 on the starboard engine. Tested with computer and the other 4 are spot on.

So far, have changed suspected coils but no positive results. Today, rain permitting, we will test cam pos., and crank pos. sensors, next throttle and shift until we find the culprit.

[boats.net]

Cam sensors or crank sensor could be at fault.

[res1xhxc]

I think I comprehend the cam sensors role but not sure about crank sensor. Desn't it basically report engine speed based on rpm of the flywheel?

[mitch]

sorry duplicate

[mitch]

have you checked the shift switch as that will cut out 2 cylinders 1.19 in your manual

also if crank sensor is fried i might be giving a over rev signal that will also shut down 5 and 6 @ 6450 . ?

only way you can tell what is buggered is to connect to yds

[res1xhxc]

2005 F250 Running Rough

Thanks Mitch, I will have an extended go at it today. Have a Yamaha Certified Master Tech. comming on site. He will connect YDIS and we will go from there. I hope this doesn't happen to any of you.

[res1xhxc]

2005 F250 Running Rough

Hey Mitch, the tec came and we went over the 250 with a fine toothed comb. All sensors tested on spec and the YDIS showed good spark on 4 cylinders. No's 1 & 6 had spark but the spark was weak. Switched out the 2 plugs and VROOM! she came back to life! Now, the twins are back in tune! Thank you for your help and guidance.


RES1XHXC

[res1xhxc]

F250 Running Rough

Mitch, I still have a problem with stbs tac. I think it may be linked to the ECU but not shure. The tac data is intermittent and sometimes totally blank. Both stbd and port gages are new... also fuel and speed data missing when tac is blank. Any ideas?