prholley

Ran the boat last saturday and going back to the ramp started getting quick beeps from the PCM. It would studder the engine for just a second when the beep would go off. Other than that the boat ran fine and never went into idle mode nor did the alarm ever stay on continuously. Ive read alot about these engines and thought it must have been a water pressure sensor or water temp sensor. I attributed this to a 2 year old impeller about to go out. I took it to the shop Monday to get impeller changed and while there I wanted to have them hook it up to the scanner to see what the alarms were. I got a call today that they changed the impeller but the boat wouldnt start. It would turn over, but no spark. They ran the diagnostics and found that the alarms were a crankshaft position, camshaft position, low oil pressure, and some others im forgetting now. Im puzzled how the boat ran fine putting it on the trailer besides the intermittent beeps, and now it wont start. Has anyone else ran into the sensor faults and did it prevent the boat from starting?

prholley

Ray, Dustin, Tommy, anyone?

Jpzaluski

I'm by no means an expert, but thinking about it logically I'd be terribly hesitant to believe that you've had multiple sensor failures simultaneously. Perhaps a faulty PCM? Bad ground? I'd start there... then begin checking each faulty sensor with a scope, etc.

prholley

Went by the shop yesterday and watched the tech test every possible thing with his computer. Everything checks out, but still no spark. He is a little thrown off, but is going to check some relays and what not. Has anyone else ever had a ignition issue on a 525?

stevesxm

are you saying he confirmed signal from the crank and cam angle sensors and the fuel pump runs ? if those two sensors talk to the ecu then the pimp should run while cranking. if no pump then no crank signal and no ignition either. confirm pump runs while cranking. that is quick way to confirm crank angle sensor. and " boat ran fine" not true at all. your own words
" boat shudder when alarm" tells me that you wre having intermittent failure / bad connection/ harness sort of thing where ecu lost signal and tripped alarm and shut boat off at the same instant and then came back on from vibration or whatever. now with him working on it he has nudged or loosend whatever was making intermitten contact to a " no contavt" position and now its a " no signal" condition.

prholley

I'm not sure what he confirmed, as I'm not sure what all can be tested with a laptop. I just know he pluged it up, ran it through a series of test that took about 10-15 mins and says everything tests fine. It just seems to me like an ignition problem on an EFI would be easier to figure out. The point of my post was in hopes that someone would throw out an obvious issue that maybe they have seen or heard with these engines in a no spark situation. I feel like this tech knows what he's doing, just frustrating not to have an answer after a week of work.

stevesxm

i understand your frustration but its not that simple. efi isn't like points and carbs which is both good news and bad. certainly w/ points and carbs you have a lot fewer variables but you don't get any of the efi advantages. in this case, there is nothing on that motor that he can't check the function and value of with a scanner and a factory workshop manual in about 45 minutes... and like you, i don't know what he is looking for either on his lap top. there are 30 different diagnostic software programs that all claim to do the job but i find the generic ones just that... generic. on my efi motors the factory manual has a diagnostic tree. " if it doesn't start check this for this value and if thats good do this and if thats bad do something else. " when you are done, the boat runs because the factory knows what it's doing. you say your guy is good and maybe he is but when a mechanic says" there is nothing wrong" what is his answer when you say " then gee... why doesn't it run ? "

prholley

He agrees obviously there is a problem, I think he's struggling to figure it out though, which is making me question if he truly does know how to fix it. I keep thinking if I took my car in and it took them a week to tell me why it wouldnt start, I would probably take it somewhere else. Problem with this, there isnt really another good option within 4 hours.

Airpacker

No starts are the easiest fault to troubl;e shoot on any efi system. The reason being that the problem IS there right now.

In order to start and run, the PCM needs several things to happen and then it either responds or it doesn't.

Step one is to verify when the ignition key is turned to the ON position, does the fuel pump come on for approx 2 seconds to prime the system. If so, the PCM is getting ignition voltage, the FP relay and FP both work. If not, either the PCM remains un powered, has very poor ground, the relay is unpowerd or ungrounded by the PCM or it relay is ng or the pump is NG. Just need to follow back from the pump to see where the power stiops and fix the issue.

For igniton to occur, the PCM needs to see a clean crankshaft position sensor signal (CKP) a clean camshaft position sensor signal (CMP) and a crank signal from the ignition switch.
If the PCM sees there three signals and it has power and GOOD ground and it actually is not the problem itself, the output signal to the ignition coils can be checked for signal from the PCM.
If the signal is good, test for power at the coils. If the signal is bad, swap PCM's with the other motor and see if it runs.
Unfortunately, there are no INTERNAL PCM tests you can do.
I believe on the 525, a relay supplies battery power to the ign coils. Check that relay for power and control circuits from the PCM accordingly. Does the relay work?

Its all basic diagnostic trouble shooting for a skilled tech. As long as it doesn't start "SOMETIMES", it shouldn't be that hard to find the answer.

bobl

If you don't get it resolved give us a call. We're about 4 hrs. south of you in Spicewood and worked on a lot of 525issues.

Bob Lloyd
Full Throttle Marine