• This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.

1999 Challenger 1800 no spark both engines

Status
Not open for further replies.
T

tonymaud

New Member
I have a 1999 Challenger 1800 with twin 787 engines. It was running fine when I winterized it and put it away for the winter. When I took it out of storage it would not start. I was not getting spark to either engine.
I am getting 2 beeps when connecting DESS and both starters turn. Checked all fuses-OK. Battery is good. Eventually I pulled the 3 connectors off of the MPEM and reseated them. I then got spark and both engines started. After sitting for a couple weeks I went to start it again and once again had no spark to either engine. I tried reseating the connectors again(several times) but no luck.
I have verified power to the MPEM, ground from MPEM to battery, Neutral safety switch is OK, fuses are good, DESS is good.
Everything seems to be in order and the engines crank but still not getting spark to either engine.
Any ideas what may be in common to the two engines that may be causing this? Any help with this would be greatly appreciated.
Let me know if you need more details. Thanks
 
Yes, all 4 grounds were hooked up. 2 large black to the starters, 1 small black to MPEM, and 1 small green to Anode.
Is it possible there is continuity from MPEM to negative battery terminal with OHM meter, but the connection is not sufficient to produce spark? All the other MPEM functions like horn,bilge, etc work fine.
 
Any water on your electrical boxes? Open and check. If the coils are submerged in water, that could cause them to fail (Hope I'm wrong)

You can check the coil trigger is getting a signal while you are there. I recall putting an LED on the trigger wire and watching it light as it was sending the signal to the coil to spark.
 
ialonso said:
Any water on your electrical boxes? Open and check. If the coils are submerged in water, that could cause them to fail (Hope I'm wrong)

You can check the coil trigger is getting a signal while you are there. I recall putting an LED on the trigger wire and watching it light as it was sending the signal to the coil to spark.
Click to expand...

Electrical boxes are dry. What should I expect to see on the coil trigger?
 
it should have power when the coil is supposed to fire. So if you wire a light to it, you should see it flicker when you crank.

flicker and no spark= coil is bad.
No flicker...How come no trigger being sent to coil?
 
I had this problem recently while by boat was in the shop. They couldn't figure it out. I towed it home over a bumpy road and it works great now. I am thinking I have a loose connection in the MPEM power circuit, but hard to diagnose when it is working. Take it for a ride...
 
steve on the water said:
I had this problem recently while by boat was in the shop. They couldn't figure it out. I towed it home over a bumpy road and it works great now. I am thinking I have a loose connection in the MPEM power circuit, but hard to diagnose when it is working. Take it for a ride...
Click to expand...

Interesting you mention this because I had it working in my driveway and when I tried it again it was after towing it an hour up to the lake.
 
what about the smaller ground wire that runs from port engine to starboard? It should be a tight connection too and goes from one magneto cover to the other, down low in the engine. I think it's a 10mm bolt on those covers
 
mobilefleet said:
what about the smaller ground wire that runs from port engine to starboard? It should be a tight connection too and goes from one magneto cover to the other, down low in the engine. I think it's a 10mm bolt on those covers
Click to expand...

Thanks. Would this be on the 1999 Challenger 1800? I did not see that wire shown on the schematic anywhere. Do you have any additional information on it like wire #, color or anything? Any information would be very helpful.
 
I too have a no spark issue on a 99 speedster with twin 787's. I've narrowed my issue down to a low voltage problem on f2 and f3 fuses under the bf1 fuse panel on the mpem. Currently I'm showing 3.2vdc when it should be 12+vdc. I have managed to get both engines to fire up by inputting 12+vdc to the bf1:f2/f3 fuses. I have a power probe, so I'm only using the boats power to do so. I haven't been able to pinpoint the exact location of the low voltage yet. I'll be checking anything that could draw power from this circuit. I know f2 runs power to the gauges and f3 runs power to the control module. Maybe your issue is like mine. Just check voltage of those two fuses when the key is attached. If your problem is like mine, I'll let you know what's causing my low voltage problem.
 
I can tell you that it is looking like an mpem issue......if the battery was ever jump started from a running car/truck or battery cables hooked up backwards, or jumper cables hooked up backwards (even momentarily), it will fry the mpem. They are very sensitive and cannot take varying voltage from vehicles. To verify your mpem is getting a trigger signal simply watch the rpm gauge of each engine as it spins over, will go to about 500 rpm on gauge. The 787 gets its signal to fire the cdi from the pickup coil inside the magneto cover of each engine. And as far as the firing of the plugs, It isn't likely that both ignition coils are bad at the same time. If it was like mine, the cdi was bad, and of course, it's integrated into the mpem. I had a good signal from pickup coil, but no power to the white wire on the starboard coil. I'm still looking for a used MPEM for my boat.
 
mobilefleet said:
I can tell you that it is looking like an mpem issue......if the battery was ever jump started from a running car/truck or battery cables hooked up backwards, or jumper cables hooked up backwards (even momentarily), it will fry the mpem. They are very sensitive and cannot take varying voltage from vehicles. To verify your mpem is getting a trigger signal simply watch the rpm gauge of each engine as it spins over, will go to about 500 rpm on gauge. The 787 gets its signal to fire the cdi from the pickup coil inside the magneto cover of each engine. And as far as the firing of the plugs, It isn't likely that both ignition coils are bad at the same time. If it was like mine, the cdi was bad, and of course, it's integrated into the mpem. I had a good signal from pickup coil, but no power to the white wire on the starboard coil. I'm still looking for a used MPEM for my boat.
Click to expand...

If the MPEM had gotten fried would it be likely to only have effected the spark circuitry? Every other function of the MPEM appears to be working.
 
Hemidakota93 said:
I too have a no spark issue on a 99 speedster with twin 787's. I've narrowed my issue down to a low voltage problem on f2 and f3 fuses under the bf1 fuse panel on the mpem. Currently I'm showing 3.2vdc when it should be 12+vdc. I have managed to get both engines to fire up by inputting 12+vdc to the bf1:f2/f3 fuses. I have a power probe, so I'm only using the boats power to do so. I haven't been able to pinpoint the exact location of the low voltage yet. I'll be checking anything that could draw power from this circuit. I know f2 runs power to the gauges and f3 runs power to the control module. Maybe your issue is like mine. Just check voltage of those two fuses when the key is attached. If your problem is like mine, I'll let you know what's causing my low voltage problem.
Click to expand...

I looked at the voltage at the fuses on the MPEM and I am getting +12V there. There is a relay on the MPEM that turns off power to the ignition system after about 30 seconds of inactivity to prevent the battery from discharging and I can see the +12V turn off at the fuse when that opens. I am having a hard time believing the MPEM is bad because everything else it controls seems to be working and I was able to get the boat to start once since this all started happening. It's got to be something stupid.
 
Last edited by a moderator:
Check c101: pin 1 grey/green or pin 2 grey/black/green for starboard trigger pulse. Pin 5 grey or pin 6 grey/black for port trigger pulse. A power probe would be handy here because it'll change beep tones every time you get a pulse. Two of those four wires should give you a pulse to trigger the coil. They are straight from the magnetos to the rpm circuits. C101: pins 10 and 11 are your outputs from the rpm circuits to the coils.
 
Last edited by a moderator:
Hemidakota93 said:
Check c101: pin 1 grey/green or pin 2 grey/black/green for starboard trigger pulse. Pin 5 grey or pin 6 grey/black for port trigger pulse. A power probe would be handy here because it'll change beep tones every time you get a pulse. Two of those four wires should give you a pulse to trigger the coil. They are straight from the magnetos to the rpm circuits. C101: pins 10 and 11 are your outputs from the rpm circuits to the coils.
Click to expand...

I don't have a power probe, but I do have a volt meter. Do you know what voltages I would expect to see on those pins or would I not be able to see anything meaningful with it because it is a pulse?
 
You guessed it. It'll be too quick to register a correct voltage. Do you have anything like an LED test light or a beeper? Something that will take minimal current to turn on or off? A regular light bulb will require too much current and won't flash with that quick of a pulse.
 
Status
Not open for further replies.

Similar threads

C
1998 seadoo challenger no spark
Replies
2
Views
301
rusty nail
rusty nail
DTH357
2003 sportster le no spark
Replies
3
Views
213
tobytd
tobytd
M
787 engine blown (98’ challenger 1800)
Replies
1
Views
336
burtshaver2021
burtshaver2021
A
Challenger 1800 Rotax vs Mercury decision
Replies
6
Views
379
Seadoo20
S
Doug Overkill
Left tachometer stopped working. With weird diagnostic event
Replies
1
Views
222
Doug Overkill
Doug Overkill
Back
Top