'97 90 SPL Spark Mystery

[kjdunne]

New to me '97 90 SPL, J90TSLEU. I have on history on this motor. Great compression, 130 - 135 on all 4 cyls. No spark on spark tester.

Went thru ignition troubleshooting per factory manual.
Stop circuit test, key switch test - OK.
Charge coil tests - OK
Sensor coil test - OK
Power Pack test - cyls 1 & 3 160 - 165 volts, cyls 2 & 4 135 volts, manual spcs 150 volts or higher. Replaced power pack with new BRP unit.
Coil tests, ohmmeter tests only - OK
Plug wire tests - 3 good, 1 bad - replaced bad one.

With new power pack I have cyls 1 & 3 147 - 148 volts, cyls 2 & 4 160 volts, still no spark or occasional spark on all cyls with spark tester.

What am I missing? I've gone end to end of factory tests except coil power tests. What are the chances of 4 coils all being bad under load? They all check OK on ohmmeter tests and look fine, no cracks, corrosion, blisters, etc.

Any suggestions gratefully accepted.

Thanks in advance.

 

[dwco5051]

Re: '97 90 SPL Spark Mystery

First thing I would do now would be to unbolt the coils and make sure the grounds are clean, refasten and tighten bolts.

 

[blimp]

Re: '97 90 SPL Spark Mystery

I would also check the kill/key switch circuit, maybe even disconnect the kill wire at the powerpack. might be grounding out somewhere and killing spark intermittently.

 

[kjdunne]

Re: '97 90 SPL Spark Mystery

I had the kill switch wire unplugged (black/yellow), no change. Will remove, clean, remount coils tomorrow.

Thanks guys.

Any additional ideas?

 

[twostroke87]

Re: '97 90 SPL Spark Mystery

Its possible the engine is not cranking fast enough, either from bad battery cables or a bad starter. Do this

Disconnect the engine from the boat, unplug harness's etc.

First try jumping the starter solenoid with a wire/screw driver whatever works, and see if you have spark .

If you still have nothing, get a good set of jumper cables, disconnect the battery leads from the boat. Take the good jumper cable set, ground the engine and sent voltage directly to the starter.

 

[twostroke87]

Re: '97 90 SPL Spark Mystery

also, if after all that it still doesn't spark, take the spark plugs out and crank it without them, if there is a starter issue (even a slight one) the engine will spin much faster without the plugs in, and if that is indeed the problem, you should have spark then.

 

[kjdunne]

Re: '97 90 SPL Spark Mystery

Went thru above suggestions one at a time. Removed and cleaned coils, they weren't too bad, but they're better now. No spark on tester.
Unplugged engine to boat harness. No spark.
Removed spark plugs so engine would crank faster. Spark on cyl 3, sometimes. This cyl has the new spark plug wire.
I moved this new wire to the other coils and had spark as long as I held a little side pressure on the plug boot. Tested other wires with side pressure on them and have good, reliable spark!
Reinstalled spark plugs, reconnected harness, still have spark as long as I hold side pressure on the plug boots.
Will replace all plug wires just because it won't hurt anything, and replace spark tester with one that has a top that isn't smaller than the spark plug tops!
Not sure now if old power pack was bad.
Thanks for your suggestions, and I'll repost when I get this motor running.

 

[kjdunne]

Re: '97 90 SPL Spark Mystery

P.S. what are your opinions on aftermarket plug wires as sold here on iboats vs OEM? I like iboats prices better unless the wires are not so good.

Thanks again guys.

 

[James R]

Re: '97 90 SPL Spark Mystery

Frankly I prefer to make my own but Iboats sell good product.