2002 Prostar w/ LTR 330 - Crank but No Spark

[ILCPROSTAR]

End of last year - last run of the year boat died and found middle 15amp fuse was burned up. Replaced this and boat started normally. Then I winterized boat/disconnected removed battery (two negative leads off battery and two positive - with one of the positive leads going to fuse/circuit block - Hi AMP 40amp).

This season, I replaced water pump - had to really hammer the old one off with a block of wood - possibly affected Crank Position Sensors? Also replaced thermostat and gaskets (new gaskets did not have brass rings to maintain electrical continuity like on my old mercruiser 5.7 - something particular to a sterndrive perhaps?)

Next, I began dewinterizing - after replacing all engine block plugs, hoses, and hooking up battery I turned the key - boat cranked normally but I did see a puff of white smoke come from the ignition coil/module area. After not starting, I hooked up the spark tester - no spark upon further cranking.

Safety lanyard circuit has been jumped and same behavior. Fuel pump energizes - i can hear it prime for 2 seconds or so. Confirmed all 15 amp fuses are intact. Tested the three relays near the ECM and they are good. Bought a used Ignition Control Module off ebay and tried that - still no spark.

I'm waiting for new crank position sensors and new coils.

As I fire off the parts cannon, I'm likely going to replace the coils next since that's where the smoke came from.

Anything in this trail of tears that is a red flag or any advice on where to go from here?

[mtajpa]

Did you disconnect the crank sensors for any reason? There is a thread on here where multiple problems were possibly corrected however the OP accidentally swapped the connectors to the crank position sensors which ended up causing him a lot of grief. I believe he used the color code when he connected them which was incorrect. He finally swapped them and his fired right up.
Sounds like you are on the right track. Double check your ground wire continuity and connections as the ECM switches the ground connections to activate things. There are 3 that go to the ECM and bolted to the block.
Good Luck.

[ILCPROSTAR]

Yeah - I read the same thread about the guy mixing up his CPS connectors - I've only disconnected mine one at a time to inspect the connections. I think you're right about getting additional comfort with the wiring and grounds - that will be time well spent. When you say "test ground wire continuity" Is it a valid test to take a test light around to the various grounds, touch them and if it lights up (other test light lead on the positive battery terminal) then I have good ground or should I be doing something else? I'm going to use this picture of the LTR wiring harness to guide me - I've highlighted all of the grounds that I can see.

[mtajpa]

Actually meant just check ground connections at block to be clean and corrosion free. Look at this link for information.

[mtajpa]

That didn't do what I wanted. This is what I meant to send. The grounds are number 450 and contuiny can be measure from the negative post to the respective pin. Use an ohm meter with the battery disconnect.

[mtajpa]

Here is the complete manual.
MEFI3CEFI3 Distributorless Ignition(2).pdf

[ILCPROSTAR]

Thanks for the manual and advice on the ground. I had a chance to check a few things and I'm leaning toward the cranks shaft position sensors. In checking the sensors, one shows infinite ohms and the other shows 560 ohms. I'm going to replace those and try again.

By the way - I haven't removed the ECM to look on the back but I was under the impression that my boat (2002 Prostar) may be MEFI4 vs. CECI or MEFI3. Is there a way to determine this short of removing the ECM?

[dpb185]

Thanks for the manual and advice on the ground. I had a chance to check a few things and I'm leaning toward the cranks shaft position sensors. In checking the sensors, one shows infinite ohms and the other shows 560 ohms. I'm going to replace those and try again.

By the way - I haven't removed the ECM to look on the back but I was under the impression that my boat (2002 Prostar) may be MEFI4 vs. CECI or MEFI3. Is there a way to determine this short of removing the ECM?

LTR crank position sensors are hard to find. You can buy them on ebay for >$100 each. I found these in China:

https://www.aliexpress.com/item/2251832502597738.html

I haven't tried them (mine are working) but I'm pretty sure these will work.

[ILCPROSTAR]

Thanks - I actually bought those a few weeks ago and they just arrived. They look decent. I also purchased a set off ebay: https://www.ebay.com/itm/175065784548

I'll be interested to see if the ebay ones are any different.

[dpb185]

Thanks - I actually bought those a few weeks ago and they just arrived. They look decent. I also purchased a set off ebay: https://www.ebay.com/itm/175065784548

I'll be interested to see if the ebay ones are any different.

How do you test them ? Mine are still in the package. The buy was more of a checking-the-box that I had a spare kind of thing. I'd hate to find they weren't any good when I need them.

[ILCPROSTAR]

I don't think it's a conclusive test but I was planning on at least doing an ohm test of the sensors to see if they are in the 650 ohms range (I saw in a prior post that this is the target ohm value). I've watched some youtube's that show the best way to test these is with a scope and power input - in other words, in a running engine.

[dpb185]

I don't think it's a conclusive test but I was planning on at least doing an ohm test of the sensors to see if they are in the 650 ohms range (I saw in a prior post that this is the target ohm value). I've watched some youtube's that show the best way to test these is with a scope and power input - in other words, in a running engine.

I just testing the ohms on mine in the garage, they ranged between 719-750 ohms. But I agree you can't really tell without looking at the output signal. Possibly measure voltage when waving a piece of metal in from of them ? I'm not an instrument (or electrical for that matter) guy so someone out there probably has a lot more knowledge than me.

[ILCPROSTAR]

Besides the CPS's, what are the other scarce parts that we should keep on hand for these boats/motors?

[dpb185]

That's my winter project this year. I don't necessarily need every part of hand but to at least, at a minimum, identify where to get them (PN, vendor) would be useful.
Off the top of my head:
1) Crank position sensors
2) Water temp (for ECM not gauges)
3) Oil pressure switch (same ECM not gauge)
4) Throttle position sensor
5) Knock sensor

Need some more research (Idle Air ?, MAP ?). The CPS is the worst one by far that I've seen reading this board. The other are available at the usual ski boat vendors.

[ILCPROSTAR]

Good list. I purchased a used ignition control module as well and will keep that on hand - did not have any luck finding new ICM's. Depending on how far you want to go, I suppose a backup ECM could be worthwhile as well.