240hp merc M2 jet (2001 Challenger) - HELP
Posted 04 June 2012 - 09:06 AM
Posted 07 June 2012 - 09:27 AM
Posted 07 June 2012 - 09:58 AM
There are a couple of fuel pumps also. One is high pressure and one isn't. Checking the high pressure pump is relatively easy, and I'd check that before doing the fuel injectors.
The way that you described the event, it sounds like everything started off good, but then went bad while continuing to drive. Did the rpm drop with the top end speed, or did it mantain the rpm and the speed just contimnue to decrease? Over how long, a short while(minutes) or really fast (seconds)?
Good Luck - hopefully, cleaning the fuel injectors will fix the problem. It surely can't hurt anything - except your wallet.
Posted 08 June 2012 - 03:27 PM
Posted 26 June 2012 - 04:22 PM
Posted 02 July 2012 - 08:05 AM
Anyone have a similar problem or an idea on what else could be the problem (merc dealer still thinks it's dirty injectors- and want to pull the engine)? With the condition of all of the fuel filters were in (very very clean - near new looking) it is hard to believe that any amount of dirt would have made its way to the injectors...let alone all of them IMO. Could it be the TPS? does anyone have experience with a bad one? Anythoughts on a bad rev limiter (what are the symptoms) even though it still sounds like it is a fuel issue and simply starving for fuel and getting more plugged up as the engine runs.
Posted 02 July 2012 - 10:58 AM
These EFI engines are very dependent on good incoming data from the sensors.
You mentioned that you changed the head temp sensor on the port side with no change, but did you also change the coolent temp sender on the starboard side? If you have a Mercury Service Manual, page 3D-23 tells you all about the semsor interaction with the ECM.
I think that is where your trouble lies.
I had a similar issue and I found out that the Engine Control Module will go into a "safe operating mode", if the sensors are not sending good info to it.
Last year I changed the air temp sensor, the head temp sensor, and the coolent temp sensor - and it allowed the Control Module to operate normally again.
Posted 03 July 2012 - 08:09 AM
Posted 03 July 2012 - 09:37 AM
Posted 03 July 2012 - 06:31 PM
Good Luck and let us know if these fix the problem.
Posted 04 July 2012 - 09:00 AM
I reviewed the wiring diagram in the service manual and confirmed that the head temp sensor and the TPS inputs to the 82403 ECM are connected. That makes sense because they would adjust the fuel mix based on engine head temp and speed together in order to make teh right mix of fuel/air. The starboard side temp sender is sending data to the Ignition Control Module. That is a small black rectangular box mounted with 3 long screws holding it on top of another one that looks the same.
My troubles last year were 1) smoking at start up, and hard starting plus 2) engine stuck in safe mode.
The air temp sensor tested bad - it was 50 degrees outside, and the thing said it ws 90 degrees - that caused the engine to think it was hot when it really wasn't. I replaced the port side head temp sensor at that time also, but in hind sight probably didn't actually need to.
The engine stuck in safe operating mode - couldn't go faster than 25-30mph at WOT. That problem was resolved when I installed a new temp sender (starboard side). I had started with replacing the ignition control module #85716972 @$159 - thinking that it HAD to be the culprit. The problem continued to exist until out of frustration, I swapped the temp sender - and the darn thing returned to full operating mode.
According to the wiring diagram, the data flows between the ignition control module, the rest of the electrical devices (stator, trigger, CDM's voltage regulators) and the 82403 ECM. The air temp, head temp, and throttle position sensors send data to the 82403 ECM - which together make the engine run.
Your problem no longer seems to be about starting up, or even idling - it is when you try to accelerate. The funny thing is that some of the sensors data doesn't seem to matter at WOT, but getting it to run between idle and wide open depends on the darn sensors and control modules to work properly.
I am hoping that is your problem - but, if not I suppose it might be the TPS or the ignition control module. Hard to tell if they don't have the engine diagnostic computer. The TPS is easy to check - it is held on by 2 screws and be checked using a volt/ohm meter for continuity. It is really nothing more than a rotating variable resistor. I read that they do get worn out in spots over time - but, that doesn't sound like what is happening on yours. Yours seems more like the computer is deciding not to let the engine get the correct spark/fuel/air mixture - for anything other than idle.
Posted 05 July 2012 - 02:57 PM
I thought about the TPS too but the service manual indicates is does not effect WOT but instead works with the idle through the WOT, i can't even get to WOT and if i do it's about 10mph (at about 75% throttle) if i go to full, it dies. If the sensors don't change anything i may have the dealer check the TPS and whatever else they can think of. I hate loosing all of this time during the season on dry land. I appeciate the ideas and input you have had.
Posted 07 July 2012 - 11:37 AM
Posted 08 July 2012 - 07:46 AM
The fact that you can idle but not accelerate at all, plus that you have had the fuel pumps checks, still leads me to believe the problem is electronic related. Make sure the mechanic is using a diagnostic device to check the engine sensors both with key on not running and while running.
I had to swap out my TPS also, and I was pretty sure that it wasn't working because when I checked it using the computer it didn't read out what the manual said it should. I read lower, but not the correct values. I had bought a used one from a guy parting out for alot less than new price - and it fixed my problem immediately.
The thing with these EFI engines is that when you find the thing that is broke and replace the part - it immediately resolves the issue. You shouldn't need to float around and wait for anything to suddenly change to fix the problem.
As for the Ignition control module and the Stator idea - All of the rest of the electronic parts (Stator, Trigger, etc) can be tested to check if they are within allowable working specifications. That doesn't necessarily mean that they are good or bad - but in most cases will give an indication as to if they are working at all.
The thing is that your boat starts and it idles - so I am hesitant to say that the Stator or Trigger. I would think that if it was either of those, the engine wouldn't idle without noticeable side affects.
The only other sensor that might cause the issue is the MAP sensor, and that one isn't serviceable because it is on the main ECM box - the diagontis tool (computer) should be able to tell you if that is working or not.
It pulls data by sucking air via a small vacuum tube connected between the ECM box and the Manifold. They tell you to check it for cracks and that it is connected. That sensor does control the amount of air in the mix, and it is a very important sensor. Make sure that one is tested also.
The way you described the original event (slowing down over a time period) doesn't make me think the ignition control module is the problem, because I 've found that control modules either work or the they don't work. They do not usually go from working to not working a little bit at a time with those. It is all or nothing.
At this point, I would start by going through all of the trouble shooting tests that are listed in the books - startig with the electronic ignition.
If you take it to another mechanic, make sure they have a computer that can connect to the Mercury outboard with the 82403 ECM.
Posted 15 July 2012 - 09:06 AM
Pulled the boat out, again checked the the intake for obstuctions as well as looked through the rear nozzel. Looked fine no obstructions. Ran it again on the hose, to flush it out, ran fine and again would rev up perfectly past idle on the hose?
Posted 15 July 2012 - 07:55 PM
This has got to be very frustrating for you by now.
A very long shot - Have you checked the exhaust hoses for delamination?
If it runs on the trailer, what is different about it being on the water?
Posted 16 July 2012 - 08:06 AM
Posted 16 July 2012 - 10:13 AM
Being in the water does put a load due to the jet pump wanting to push water through it, vs sitting out of the water with the hose under normal water pressure. I cannot recall if you had the cylinder pressure checked, but that seems like a good place to check.
Due to the way the failure occurred (slowly, during a long ride), it does seem like when the throttle asks for more speed and the engine chugs - it almost sounds like one of 2 things could be happening.
1) something is binding up - perhaps a bearing in the jet drive?
2) the fuel/air/spark mix during detonation isn't able to change as is needed, when accelerating.
I think there is a section in the manual that will give step by step instructions for checking the jet pump.
The second one can be trickier because of the electronics, but with that one I'd start with compression. You have already checked fuel pumps, and now the sensors have been replaced. The next thing to check would be the rest of the spark generating components. The stator, the trigger, the ignition control module, cdms, the plugs, the voltage regulators.
The manual has detailed instructions on how to test/check those, with a diagnostic tester.
If it idles fine (in and out of the water), I do not think the injectors are the problem. If they were plugged up, they wouldn't work in any condition. This has to do with something needed that controls or provides the right amount of spark, fuel, or air flow while accelerating. Has the diagnostics showed that the MAP sensor is working?
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