2008 GTI 155 Running Uber Rich

[LargeJohn]

Recently acquired a 2008 GTI SE 155. Plugs were fouled when I bought it, so I installed new NGK's and fired it right up. Engine produced smoke and would not reach 5000 rpm. Pulled it home, pulled the plugs and they were black and wet after about 15 minutes of operation. Pulled the fuel rail to take a look at injectors and all 3 seem to be dumping excessive fuel.

I suspect a bad sensor (TPS, MATS or IACV), but don't have a way to read engine codes (CANDOO order placed, but won't be delivered for a week). I would like to proceed with some troubleshooting, but I realize that may be difficult until I have the reader.

Has anyone seen this symptom? Could it be related to the fuel pump or regulator?

Anything obvious that I could check? I would like to get a headstart on the parts, because once I have a diagnosis, I will most likely have a week's wait to order parts.

 

[Milehighguy303]

You are beyond my skill and ability, but it sounds like you are dealing with an driveability issue that will require the Candoo. Hope you get it and it can give you good info to repair. I don’t know any manual diagnostics for what you are experiencing. Let us know what you find and try.

 

[LargeJohn]

Little progress. The TPS tested out of range for impedance. So I replaced and reset thanks to Candoo Pro. Machine had a P0505 code stored so I removed and cleaned the Idle Control Valve. If this doesn't fix I will order a replacement. Also, going to install a new battery. I think the current one is undersized and on it's last leg. Coil voltage is marginal when cranking and hard to start.

 

[LargeJohn]

Fresh battery and fresh set of plugs, then it fired right up and idled smooth at 1700 rpm.

I connected a hose and revved it well beyond the previous 5,000 rpm wall. Engine produced some blue smoke, a little rough, and it seems to still be too rich. I let it run for 2-3 minutes to see if any new codes were stored (NONE WERE PRESENT WHEN SCANNED AFTERWARD).

Shut it down and pulled the plugs. They already appeared to be blackening after less than 5 minutes running. I suspect the injectors are dirty and not producing the fine spray that they should be. All (3) tested slightly outside normal range (13.2 ohms).

Will cleaning the injectors improve their performance or do I need to purchase new injectors?

 

[mikidymac]

I would send them out to a dedicated injection testing and cleaning shop.

 

[LargeJohn]

I would send them out to a dedicated injection testing and cleaning shop.

Can you recommend an on-line cleaner? I could not find anyone local.

 

[Milehighguy303]

How many hours do you have on this ski? How well do you think oil change maintenance was performed before you bought it? How long has the ski sat before you ran it? Have you put fresh gas in the tank?

I would check compression before I check fuel injectors. Just reading this forum and personal experience leads me to believe seadoo injectors rarely fail, especially all three. I occasionally pour a can of B-12 Chemtool carb cleaner into a full tank to keep my ingectors at their best. See what your compression is before pulling injectors. And I don’t know if an auto shop could bench test the injectors or not - I don’t know how much they are but if your compression is good and you run it in the lake for a little bit with no codes, then start to suspect injectors or coils. That is my opinion.

 

[LargeJohn]

102 hours.

No expectations on maintenance....

Definitely sat for 2-3 years.

Tank was near empty when purchased. I added a couple gallons fresh gas.

Compression tested consistently across all (3) cylinders--130 - 135.

Injectors seem to be functioning correctly, but fuel flow doesn't seem to be as "atomized" as some injector videos that I've seen. I'm suspecting that there may be some dirt/varnish on the nozzles. I'm going to attempt flushing them with some carb cleaner to see if that makes a difference.

 

[LargeJohn]

Couldn't find anyone local to do the cleaning. So I decided to order replacements. Upon close inspection the old ones looked pretty bad. Brass on inlet side was corroded and I could not pull the filter basket out despite a fair amount of coaxing with vise-grips.

Seems to be idling OK, but puts out some bluish/grey smoke. I am planning to remove all the old gasoline and install the new injectors. Hopefully, that will be the final step.

 

[Milehighguy303]

I am a little concerned, but mostly curious with your compression test results. I have read other threads in the forum about compression being ideally 165-180 on the 155 HP engines. The shop manual only references a leak down test (I think essentially opposite of a compression test) and doesn’t give compression figures or acceptable range. But I think fuel injectors is a good step on a new to you machine that has sat and you don’t have any knowledge or history on its prior performance.

It might be comforting for someone with more knowledge and experience to weigh in on your 130-135 compression results. You performed your test with wide open throttle, I presume?

 

[LargeJohn]

Yes. WOT/drown mode with all plugs removed.

I had the same thought, but most of what I've read references the compression differences between cylinders. Also, I did a single test with a cheap set of Harbor Freight gauges, so not completely confident in their calibration. If the injectors don't eliminate the roughness and smoke, then a leak-down test is probably my next step.

 

[Milehighguy303]

Just curious if you have installed new fuel injectors and if you have been on the water yet to test your results? I am heading out today with the kids and was thinking of your machine...

 

[Arkie Bob]

Being a pedal-to-the Metal kind of guy, I'd take it out on some water and run the ass off it and see if excess fuel/soot/unburied crud in cylinders, exhaust system doesn't burn out and issue clear itself.

 

[LargeJohn]

Sorry for not following up sooner. I appreciate everyone's input.

Anyway, I did install new injectors, pumped out all the old fuel and added a few gallons of premium.

Finally made it to the lake yesterday. Backed off the trailer, idled out past the no wake buoys, and started to accelerate. Made it to 4,000 rpm about half throttle and hit a wall at 15-20 mph. Would no go any farther. Pulled back into the dock and loaded it up. Got back to the garage and pulled the plugs. Sure enough they were black as coal after only 10 minutes of running.

I decided to remove and clean the throttle body to ensure proper airflow. Everything seemed to be in good shape, but I gave it a light cleaning and lubed all the moving parts.

Now, I'm focusing on the spark. I assumed that the spark was adequate since the machine has always started well, especially after replacing the battery. In any case I pulled the coil sticks and did a resistance test. The primary resistance on all (3) coils was 1.6 to 1.7 ohms. According to the shop manual, these are supposed to be between 0.85 and 1.15 ohms. I've never seen a coil fail in this manner, but they are clearly out of spec.

So, I guess my next step will be verifying the continuity of the voltage and ground circuits at the coil sockets, before purchasing new coils.

 

[benjilafouine]

Sounds like your engine may be burning oil (and that would be bad). Does it smoke or smell when running (someone following you could tell)? Someone mentioned oil maintenance in this thread but I didn't see any answer on that subject.

I was on the lake today and followed a guy on a 4-tec and I told myself: what's that smell? On the lake, we are used to smell 2-stroke oil smoke but this time it smelled like this ski was burning 4-stroke oil. The guy never slowed down so I didn't get the chance to tell him (I wanted to). I guess he's in for some trouble in his short term horizon...

I am just saying that because your spark plugs are fouled black in no time.

Benji.

 

[LargeJohn]

Benji, I think that it has been burning a little bit--maybe a stuck ring after sitting, but the plugs look dry (like a rich condition). I would expect an oily residue if it was excessive oil in the cylinder. Also, I've been keeping a close eye on the oil level and haven't noticed a change.

 

[LargeJohn]

Did a thorough inspection and cleaning of the coil packs today. Realized that my resistance readings aren't that bad--the test leads that I was using accounted for 0.5-0.6 ohms. DOH!!

Verified voltage on all (3) coils and checked continuity of ground detectors to ECU.

No visible cracks or damage to the coils, but I did discover that one of the coil packs is missing its orange seal around the connector. Not sure that this is related, but I'm going to look for a replacement to take that out of the equation.

 

[LargeJohn]

Planning to re-test fuel pressure key on and while running. All symptoms seem to point to excess fuel.

I will post results later tonight.

 

[LargeJohn]

Fuel pressure tests good. 42 psi with key on. Slight bounce in pressure while idling (maybe +/-3 psi). Revved up to 5700 rpm and fuel pressure stayed in the +/-5 psi range. Also, verified that injectors are not leaking while pressurized. Still fishing....

Next step may be a bottle of Techron.

 

[LargeJohn]

Got the missing seal for the coil pack and put everything back together.

Definitely have improved throttle response. Don't know if the #1 coil (with the missing seal) was leaking some current and firing intermittently or what.

Time for another water test, but not sure when I'll be able to get there....

 

[LargeJohn]

Out of town for a week, but got a chance to take another look today.

After running a little while with the seat off, I noticed that I had exhaust leaking into the hull. On closer inspection, the exhaust clamp (at the header) was broken and loose. I've ordered a replacement and hope that this is the final missing piece of the puzzle...