'99 GTX Limited No Spark

[WaveEater]

I just installed a rebuilt engine in my GTX all went well during the install untill the first atempt to start it. It cranks over but no spark. I am getting a good pulse off the trigger coil but no pulse to the ignition coils. help...

Thanks,

Brad

[Bill O'Neal]

You probably have a pin connector that is not making contact. You can run a test on the white wire at the coils to see if they are getting a signal. First try unplugging and replugging in all of the ignition connectors and testing the sparkplugs for spark. Check all fuses too.

[John Kubiak]

This is a very common problem that occurs when the ground connections at the mag housing are left off. I have had to correct this on many DIY repairs as well as some "professional" work [img]graemlins/uts.gif[/img]

[Bill O'Neal]

Sea Doo Tech,
Good advice ! Many forget to put the ground wires back onto the mag housing tab when re-installing the motor.
Same goes for the small black wire on a 785 coil box. Very common to forget to connect it to the negative side of the battery.

[WaveEater]

Thanks for the suggestions but the 2 wires that attach to the mag housing are on. I am getting a good ground on the black w/yellow wire of the trigger coil and a good pulse on the yellow w/white wire.
The enginge cranks fine, I believe that if the ground wires are left off the mag housing nothing happens. Everything seems fine, the gauge displays all temp/hour info and everything seems to be connected properly, The only problem is that I am not getting a pulse to the primary side of the ignition coils.

Brad

[Bill O'Neal]

Brad,
I had a GSXL into the shop last spring with the exact same problem. I got it after several dealerships and two independant shops had failed to find the problem. After swapping every single part and wire loom, including the magneto, the MPEM and coil box, I still had the problem. Eventually, the problem turned out to be a pin connector in one of the AMP connectors at the mpem. That was very surprizing to me, because I had tried two different wire looms and connector sets and a different MPEM from a known good working ski. Sometimes these things can drive you crazy.

[John Kubiak]

There is another possibility, and beleive me, I have done it myself!!! There is a good possibility that the trigger pickup coil is installed 180 degrees from normal, you can bolt it up this way and everything will fit together, as normal. I did this on a 787 that uses a similar set up, and I do beleive the same trigger coil. This thing drove me nuts for a day and a half BEFORE I figured it out!!!! check this before you try anything else. the ohms tests were perfect, the dynamic tests (pulse from trigger coil) were ok but no spark. flipped the trigger coil over to the correct position and it ran perfectly! [img]/graemlins/angryfire.gif[/img] [img]/graemlins/angryfire.gif[/img]

[ December 11, 2001: Message edited by: Sea-Doo Tech 13736 ]

[ December 11, 2001: Message edited by: Sea-Doo Tech 13736 ]</p>

[WaveEater]

Thanks I'll try that. It sounds like a very likly solution.
The rebuild engine that I just installed came complete with all electronics and a rebuilt starter installed. When I ask the guy i bought it from about the possiblility of the trigger coil being put in wrong during the aassymbly, he said it was very unlikley since he didn't remove it during the rebuild.
Never take anything for granted... I'll check it out tonight and respond with the results.

Thanks,
Brad

[WaveEater]

well that wasn't the problem. The trigger sensor looks fine, is installed correct, and wired correct. Still no spark or primary signal to coils.

Any other suggestions?

[WaveEater]

I am still looking for a solution to this problem. What are the chances that the MPEM may be bad?

[Bill O'Neal]

Wave Eater,
I'd say very slim if the MPEM was in good working condition before you swapped the motor.

Did you know that the ignition has a feature that shuts off the spark when the battery is a little too low ? It will still crank over with the starter, but it won't spark at the plugs. It is in there to prevent damage to the ignition when the power supply drops below about 11 volts.

How many volts are in your battery?

[WaveEater]

The battery has good voltage. I have tried with the charger on it and have been testing with the plugs removed to reduce the stress on the starter.

[WaveEater]

which pin does the computer take this reference voltage from.
Is there any other situations that would cause the computer to allow the enginge to crank but not fire. low oil, low fuel,etc... the oil and fuel are fine.

[Bill O'Neal]

Wave,
I'm not sure which pin is the correct pin. But, the mpem has a built in device that lets it know when to shut down the spark, so I assume it would be the pin that carries the power from the battery to the mpem.You had better refer to the schemetic for your year and model of watercraft to locate the correct wires.

Like I said in the earlier post about the GSXL, my problem of no spark was eventually fixed by swapping out the amp connector that had the wiring that fed the coil from the mpem. It had a bad pin connector in it. Before we got to that point, we tried a known good mpem and a few other known good parts that could have caused the no spark situation also.

How many volts is your battery producing ?

[WaveEater]

The Battery has 13.8 volts, all the pins in the connector seem to be fine.