Utopia 185 200 DFI Not Firing all Cylinders

[fowlerrudi]

Well, I thought I had this thing at 100%, but not quite yet. It’s an 01 Utopia 185, 200hp DFI. 130 hrs. New plugs, fresh fuel, new filters. Revving 5000 rpm, 42mph indicated, probably much less on GPS. I understand I should be around 5600 with this engine. I suspected ignition. I repaired some potentially bad plug caps and uses a timing light to check for fire on all lines. When I turn left I get more rpm, right I get less. Single jet and single engine. With the extra 600 rpm I’m sure I’d see 50-55 indicated as on my old boat. Would tps cause this? At first my throttle wasn’t opening up all the way so adjusted it as much as I could to get the butterfly to open, but the little roller cam is a bit worn so I might be only getting 95-98% throttle, just a thought. Check out the YouTube video:

 

[Dr Honda]

The little more on the throttle valve won't equate to a jump of 500/600 rpm. Just as an fyi. But that loss would tell me you aren't firing properly on all the plugs. An inductive timing light will fire even if it sees a tiny voltage hit. The best way to check is get a couple in-line spark tools, and just watch when under way.

The left/right thing... seems like all jet drives do that. It has to do with the load being diverted, and how it re-enters the water.

Listening to the vid... the engine sounds very happy, but you are right... a little low on power. Have you checked the compression? If it's low... so will your top rpm. Also, have you checked your air and fuel pressure while running? (80 and 90 psi)

 

[fowlerrudi]

I’m too scared to do a compression test lol! Ignorance is bliss! To be honest getting at the plugs on this boat is a huge curse. I think I will buy another coil and swap it out with each cylinder and see if I can locate a dead one. The inline tester sounds cool but who am I going to convince to watch that while I’m driving? When I swapped plugs I didn’t go with iridium as recommended, just a platinum ngk with same heat rating. I doubt that would matter. Another thing I should mention is I noticed the side mounted oil tank has the sensor unhooked and the harness is just plugged into itself. I doubt this would do anything roger, unless it is expecting a certain resistance range....
Maybe I should switch to the recommended plugs and do a compression test at the same time.

 

[Dr Honda]

....
Maybe I should switch to the recommended plugs and do a compression test at the same time.

Absolutely. The heat range is only relevant on the same style plug. SO... an "8" on a BxES series plug is not the same as an 8 on and IFx type.

So, pull the plugs... screw in a compression gage... crank... read. Easy.

 

[fowlerrudi]

Is this the plug I should be using? IZFR5G

 

[fowlerrudi]

Dug into her again tonight. Tested compression on three cylinders. And swapped plugs out for laser iridiums. One plug was as clean as a whistle. We put an in-line tester on it as recommended by Dr. Honda and sure enough. It signs off. Much better year than the induction timing light. See video:

 

[dblackstone]

that one clean plug, did that one have spark? Was the plug wire on it tight?

 

[Dr Honda]

Yep... that's not good.

Since it's a DI engine... I would also check it's mate. The engine is broken into 3 banks of spark. If it's mate plug is dead too... then it's the controller. If all the other plugs are firing... it's the coil. (or the associated wiring)

 

[fowlerrudi]

Crap, I posted the wrong video last night. Should have been this one:

 

[fowlerrudi]

Good news, excellent compression, all within 5 lbs of each other. New iridium plugs installed. Anyone who tells you it is easy to install plugs in a DI utopia is crazier than the birds. Maybe if you aren’t a 200 lb 6’3” creature. My flywheel has branded me. The bad news is, I bought a 5 wire coil instead of a 3 wire. DUMB DUMB DUMB! Redo.

 

[dblackstone]

Number 5, lower left was a bitch for me, took me as long to do that one as the others. Isn't designed for big hands to get in there. I had to remove the plug for that injector to get my hand in to put in new plug.

 

[fowlerrudi]

Oh what a treat! Just did some more diagnosing and turns out the coil is fine. The misfire is following the #6 wire that is feeding the coil. I switched coil wires and plug wires and the loser coil is working fine....

 

[fowlerrudi]

What are the chances of this being a coil driver issue at the ECU? If it is the coil driver, would two coils drop? I’m going to trace wires tonight, very odd that it sparks every time at startup then signs off. One spark plug only. Thanks

 

[Dr Honda]

You can move the driver packs to test that. I doubt it's the ECU.

 

[fowlerrudi]

We switched driver packs, and the driver packs are fine. We tested each of the three wires between the driver and the coil with ohm meter and they tested ok. We also went further and jumpered a wire from the plug on the coil to the plug on the driver to eliminate the possibility of it being a break in the wire. We did this on all three wires coming off the coil. We also tested and jumped each of the wires coming from the ECU to the driver, no difference. At this point it is looking like the ECU. Thoughts? Into it deep as we speak.

 

[Dr Honda]

Well... that's a first Opti ECU I've seen go bad. I would invest in a RInda Scan tool. It will be able to watch and test a lot of things on that ECU. But... check on ebay... I'm guessing you can find a 200 Opti ECU at a reasonable price.

 

[fowlerrudi]

I can find ones on Ebay, from a 2000 outboard. Would I just be able to plug and play? Or need remapped for me 2001 jet? I opened it up and checking mosfits and caps, cause that’s all I know how to do. Looks like new in here:

 

[Dr Honda]

Very nice. I would look at the SCR/FET that drives that spark line.

And yes... as far as I know... any of the 200 Opti ECU's should work.

 

[fowlerrudi]

I took it to a friend who plays with this stuff for a living, electrical engineer who works in the biomedical field. He swapped the mosfets from the bank that he traced from the faulty signal lead, with the mosfets from a good bank. Since we didn’t have any new mosfets. I’ll try tonight and see if the problem moves to the other bank. If so, $5 in mosfets and some more timbits for his kids and hopefully back in action. Otherwise, new to me Ecu will be heading my way. It’s super hard to diagnose because it works fine for 5 seconds when it first starts up.

 

[fowlerrudi]

Alrighty, installed the ECU/PCM with the misfits swapped around, same old story. Sad. I went through all my tests again, jumpering wires, swapping ignition module/coil drivers, coil swap on 1,3 and 2,4. Everything points to the pcm. My friend wishes he took his oscilloscope home with me to compare the signals on a good signal wire from pcm to the bad one. We ended up putting the multimeter on the signal wire (positive) and the negative to the negative on battery. While engine is running, the good signal shows 0.3v once the key is on, then it increases over 1.0v with rpm. It is proportional with engine speed. Kind of a redneck way to detect signal but it worked. On the bad line, it got 0.3v and increased with engine rpm, then signed off and quit working, like an entitied millennial. The video shows this happening with the spark tester in the background. See the following.

Good Signal Wire:

Bad Signal Wire:

 

[fowlerrudi]

Is it possible that a stuck injector will cause spark to stop? The dealer put it in scanner and this showed up. Also, he shut down each cylinder by itself and turning off #6 made no difference and turning off #2 made no difference. Here are the codes while boat is running:

 

[fowlerrudi]

Success! I have to share what I’ve learned. The ecu is not bad. The ecu/pcm was not sending a signal to fire coil 6 after 5 seconds of running. This is because the computer is smart enough to know when there is an injector failure. Once the computer detects an open circuit on air or fuel injector, it is actually smart enough to shut down that cylinder. Great info right there. So, I put the ecu back in her metal box and hopefully we don’t see each other again.

I’m glad my buddy is good at soldering, cause we got right into that one, and ecu was actually good, even though in my head it was not. So Dr. Honda is still right in saying he’s never seen an ecu/pcm go!

When I took my air and fuel injectors out to test/clean them, I checked continuity between the common wire on all of them. Nothing. I got digging and that entire trunk wire that branches to all the injectors was corroded and black behind it’s sheathing. I ended up cutting all the wires out and putting in new ones, right up to the plugs. I have no idea how it was running even on 5 cylinders. Should have run on 3 tops.

I’ve spent a ton of hours at this, but still a cheap education. I hope this helps someone in the future. I was out today and got my 50+mph and 5650 rpm. I will mention however that it did drop back to 5 cyl on me, but I know exactly where it is doing it now. I will probably pick up another harness, or just bring this one in on the kitchen table and redo it all.

Video:

 

[Dr Honda]

Thanks for all the info, and follow up. I've personally never had to dig that deep into the Opti engine. The majority of the boats got the 240 or 210 engine. I guess it's almost mandatory to buy a scan tool for them, since it can tell you exactly what it's seeing.

I'm glad you and your buddy were able to look that close into the Opti ECU... that was an education for me. I have my EE, and have been a hobbyist for a long time, but never had the need to crack open an Opti ECU. But... along with my EE, I have Bio, Liberal arts, and Physics with a math minor. (I enjoyed school) The O-scope reading would have been good too.

 

[fowlerrudi]

Here we are one year later, and I haven’t been able to get my 6th cylinder online. I am unable to find a harness with the correct part number without spending $1500, and no doubt it would be back ordered. I did order a used harness on Ebay and soldered and shrink wrapped in new connectors.

Cylinder 2 is the online one that is not happy. Spark test goes for 5 seconds on startup then shuts off. I have good continuity from both my cyl 2 injectors, I even ran separate wires from the injector (fuel and air) to their respective plugs on the ecu. The ecu I believe is shutting down that cylinder on me, but I don’t know why. I’ve swapped coils, both injectors, plugs, have new plug wires. Great compression everywhere, all other 5 fire fine. I think I have to go back to the dealer to get it scanned again, I’m certain it is going to tell me that is the air or fuel injector fault, but they work fine in the other cylinders....

My Orings on the cylinders are starting to get chewed up a bit because of me pulling the injector block off so much.