Exahust Smoke, rough start after injectors and thermostat changed
brandonmayberry
Member Posts: 226 ✭✭
Rinker 242 with 350 Mag MPI. 2000 model.
Engine was running decent but lacked power coming out of the hole. I decided to send the injectors off to be cleaned and flow tested, while removing the injectors i noticed one seemed to have a broken electrical connection on it and replaced it with a new one. All the other injectors came back good except one which was recommended to be replaced and i did replace it with a new one as well. While waiting for the injectors to be returned i decided to change the thermostat as a preventative maintenance type thing. After the change of the thermostat and reinstalling the injectors the engine started right up, actually faster than ever. (this is on muffs in the drive) It ran decent but i noticed some white smoke. After running it for a few minutes and checking everything out i turned it off and back on to make sure no issued and the engine was still seeming to smoke.
My Wife said she had never seen it smoke before and we have run it on muffs in the drive quite a few times while working on things. I decided to rev the engine a little bit so i did so and she said she noticed black smoke coming out of the middle of the out drive props. I did not witness this first had as i was in the boat. I did notice however that the water when coming out of the exhaust and settling in the drive way had what appears to be ALOT of carbon in it.
Then we shut it off again and it was hard to start without giving it some gas. I hooked my rinda diacom up and it is reading fine with no fault codes. My only guess is maybe it is running on a cylinder that was not running on before due to a failed injector and it is causing it to burn off the carbon and such out of that cylinder but im no mechanic.
Any help at all is SUPER appreciated! I want to get this straightened out before winter so it will be ready for early spring without having any problems. Here is a picture of the exhaust water.
Engine was running decent but lacked power coming out of the hole. I decided to send the injectors off to be cleaned and flow tested, while removing the injectors i noticed one seemed to have a broken electrical connection on it and replaced it with a new one. All the other injectors came back good except one which was recommended to be replaced and i did replace it with a new one as well. While waiting for the injectors to be returned i decided to change the thermostat as a preventative maintenance type thing. After the change of the thermostat and reinstalling the injectors the engine started right up, actually faster than ever. (this is on muffs in the drive) It ran decent but i noticed some white smoke. After running it for a few minutes and checking everything out i turned it off and back on to make sure no issued and the engine was still seeming to smoke.
My Wife said she had never seen it smoke before and we have run it on muffs in the drive quite a few times while working on things. I decided to rev the engine a little bit so i did so and she said she noticed black smoke coming out of the middle of the out drive props. I did not witness this first had as i was in the boat. I did notice however that the water when coming out of the exhaust and settling in the drive way had what appears to be ALOT of carbon in it.
Then we shut it off again and it was hard to start without giving it some gas. I hooked my rinda diacom up and it is reading fine with no fault codes. My only guess is maybe it is running on a cylinder that was not running on before due to a failed injector and it is causing it to burn off the carbon and such out of that cylinder but im no mechanic.
Any help at all is SUPER appreciated! I want to get this straightened out before winter so it will be ready for early spring without having any problems. Here is a picture of the exhaust water.
Post edited by brandonmayberry on
Comments
06 Rinker 270
you've done two things that can impact the engine's fuel trim- you've altered the thermostat which regulates engine temperature, and you've introduced new injectors which may flow better than the old ones.
adaptive tables in your PCM are a great thing, as they adapt to the environment you're most often operating in, but, when variables change so does the fuel trim- just, slower...
at start up the engine is running off of a hard scripted table... temperature, air mass, ect. aren't regarded until a certain threshold is encountered, and at what point it 'closes loop' by adjusting based off of sensors alone. It also 'opens loop' and runs off of hard scripts when you're at or near WOT. I don't know how Merc handles it, but most car pcm's start closing loop around the 125~140* mark.
Black smoke is rich... your exhaust/water mix looks to have a sheen- looks to me like unburnt a:f mix...
Injectors install is hard to screw up- either they seat or they don't, and if they don't it's usually pretty obvious with fuel squirting everywhere, so if you don't see that you're likely fine in that regard.. one thing about them is the connectors- ev1 or ev6, and they are delicate... I once chased a lean issue to one cylinder and simply couldn't figure it out until looking closely at one blade of an ev6, which wasn't making full contact and therefor had more resistance than it should have... that was a lean issue, not a rich.. one thing is certain is you're running rich... I'm just making a point that the connections are important. rich engines run smoother, and many wouldn't notice the excess fuel and think their cleaned injectors 'sure quitened down that engine', when in fact the ultrasonic process shook the fine mesh in the basket to the point it broke some of them, or even disrupted the pintle's seat and they're letting more fuel past than it's 'sposed to... For this reason, I pretty much don't condone injector cleaning... it's more a ruse than anything, but it can be done properly, too- it's just that most don't do it properly.
I'll save the site some extra bandwidth by just suggesting you disconnect the battery, let the adaptive memory clear, and hope that is all you need to do- but I'm figuring instead you're going to have to address the injectors and/or fuel pressure before it's over with.
just break the circuit so the PCM loses the adaptive memory...
just for the record, I don't think this is it... I think he's flowing too much through those 'reconditioned' injectors.
Boat Name: King Kong
"Boat + Water = Fun"
We took the boat out last weekend and ran it for about 30 minutes hoping the computer would relearn and run at a better condition which it did run slightly better than before but it was still smoking some (the soot in the exhaust wasnt noticeable) but there was a significant lack of pour and did not run well. When i was finally able to get on plane, i would have to run full throttle to reach roughly 35mph and i normally am able to get around 45-50. Also at 3/4 throttle when i go to full throttle it falls on its face.
I dropped the boat off at the shop immediately after that test so i guess i will just see what they say. Its scheduled to be looked at next Thursday (oct 1) I hope that they find something or they simply have the idea to just unplug the battery and that will fix it so it will save me some money, otherwise i feel like we are chasing ghosts.
What i do notice that is uncommon is the loud vacuum suction noise coming form the IAC hole on the top of the engine. It usually makes some noise, but since the injector reinstall it is MUCH louder and can be heard at full throttle with the engine hatch on.
Anyways, Ive rambled alot here but i appreciate the suggestions and if they cant figure something out ill start with the batteries and such and let you know how it goes or if they do get it ill report back with the solution.
do you simply have a vacuum leak? It is pretty easy to dislodge something that will cause that...
Boat Name: King Kong
"Boat + Water = Fun"