how to test is MPEM is faulty or good- 1998 seadoo GTX LTD 951

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Ziii

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Can someone please let me know how can we test at home if MPEM is faulty or good. Also is there any way we can fix faulty MPEM
 
Send to Westside Powersports. Look them up on Facebook.
i called today morning, they were selling ignition coil and stator telling whatever you bought from other places are junk. i fail to understand that OEM is OEM part no matter which place you choose to buy.

my relay is having correct voltage of 12.9V when i try to check voltage on ignition coil i am not getting anything.

is there any way i can bypass MPEM and see if spark is good.

when i put the key i get 2 nice beeps , how can i come to the conclusion MPEM is bad ?
 
Unless, you can find a spare MPEM, I don't think you can test spark w/o a functioning MPEM. Don't buy and aftermarket MPEM. Reach out to Etemplet on here. He may can cut you a deal on a good MPEM.
 
Check the grounds under the coil mounting bolt in the rear box
disconect the white wire from the coil and connect it to a grounded test light, crank the motor.
if the test light ‘flickers’ every thing back from there is good
if not test stator
 
Thank you @tobytd - are you referring to the ground in rear electrical box or the wires grounded wherew 6pin cable is connected below pictures for your review
IMG_8738.jpegIMG_8739.jpegtha
 
Can someone please let me know how can we test at home if MPEM is faulty or good. Also is there any way we can fix faulty MPEM
The answer you don't want to hear is yes and no. Yes you can test the MPEM but only up to a point. The good news is that I believe yours is manufactured by Nippondenso rather than Mega-Tech Electro. Here are the key points: If you can get the beeper to get give you two beeps, 90% of the MPEM is working properly.

If you can get the engine to crank, using the start/stop button, even better. The problem is that the 1998 model is a wierd year because of how the ignition was set up. There are two styles of ignitions used. One style uses a single coil and fires both cylinders at the same time in what is called a "waste-spark" type ignition. The second and later version uses two ignition coils, one per cylinder. The problem occurs when people start swapping out parts and not understanding what pieces go to which system. There are two different MPEMs for each ignition system, respectively.

Since it appears you have a single coil, you can test for spark by laying the plugs touching each other, leads still connected, and then crank the engine using the start/stop button. YOU CAN NOT MANUALLY CRANK THE ENGINE BY JUMPING THE SOLENOID AND EXPECT SPARK. The MPEM generates a 350 Volt pulse to the ignition coil(coils). At home you can generally not duplicate this high of a pulsed voltage without special equipment.

The bottom line here is that you need to provide more info as to why you belive the MPEM is the problem. Have you done a resistance check on both the primary and secondary windings of the ignition coil yet? Feel free to PM me directly if you want to discuss further troubleshooting methods.

Need some background of the ski as well....when was the last time it ran correctly? Rebuilt engine?
 
This coil has been replaced, the old spark plug leads are just laying there. When was this done? Why was the coil replaced?
Since we were not getting any spark starter,stator coil was replaced by the original seller. Based on the troubleshooting we thought may be ignition coil is bad so bought newone from amazon and when i crank i get very weak spark.. trying to figure out what can be wrong
 
The answer you don't want to hear is yes and no. Yes you can test the MPEM but only up to a point. The good news is that I believe yours is manufactured by Nippondenso rather than Mega-Tech Electro. Here are the key points: If you can get the beeper to get give you two beeps, 90% of the MPEM is working properly.

If you can get the engine to crank, using the start/stop button, even better. The problem is that the 1998 model is a wierd year because of how the ignition was set up. There are two styles of ignitions used. One style uses a single coil and fires both cylinders at the same time in what is called a "waste-spark" type ignition. The second and later version uses two ignition coils, one per cylinder. The problem occurs when people start swapping out parts and not understanding what pieces go to which system. There are two different MPEMs for each ignition system, respectively.

Since it appears you have a single coil, you can test for spark by laying the plugs touching each other, leads still connected, and then crank the engine using the start/stop button. YOU CAN NOT MANUALLY CRANK THE ENGINE BY JUMPING THE SOLENOID AND EXPECT SPARK. The MPEM generates a 350 Volt pulse to the ignition coil(coils). At home you can generally not duplicate this high of a pulsed voltage without special equipment.

The bottom line here is that you need to provide more info as to why you belive the MPEM is the problem. Have you done a resistance check on both the primary and secondary windings of the ignition coil yet? Feel free to PM me directly if you want to discuss further troubleshooting methods.

Need some background of the ski as well....when was the last time it ran correctly? Rebuilt engine?
Thank you for the detailed response. I am new to jetski so doesn’t have much knowledge trying to google and fix it and getting help from experts like you and others..

When i connect the key i get 2 nice beeps
It cranks perfectly fine..
but when I connect spark plus tester it gets very weak spark which i believe is not sufficient to engine to start.
 
The spark tester is adding complexity where there is no need for one.

The proper way to test for hot spark on your particular ski is to remove BOTH plugs, keeping leads attached to both plugs, lay the plugs over the side of the hull. Secure the plugs together with a zip tie, string, etc. so their metal bases are in contact. When you crank the engine, both plugs should spark at the same time. REMEMBER, a single coil ignition forms a loop for the spark energy between the plugs. The spark energy does not return through the engine block like traditional ignition systems.
Screenshot_20221104_162107.jpg20221015_183119.jpg20221015_183429.jpg
If both plugs have a nice blue sparks, then the MPEM, nor the coil is the problem. Do you know that the spark plug caps are also supposed to have about 4.5kOhms for each cap? I'll provide a photo.
 
The spark tester is adding complexity where there is no need for one.

The proper way to test for hot spark on your particular ski is to remove BOTH plugs, keeping leads attached to both plugs, lay the plugs over the side of the hull. Secure the plugs together with a zip tie, string, etc. so their metal bases are in contact. When you crank the engine, both plugs should spark at the same time. REMEMBER, a single coil ignition forms a loop for the spark energy between the plugs. The spark energy does not return through the engine block like traditional ignition systems.
View attachment 64833View attachment 64834View attachment 64835
If both plugs have a nice blue sparks, then the MPEM, nor the coil is the problem. Do you know that the spark plug caps are also supposed to have about 4.5kOhms for each cap? I'll provide a photo.
Appreciate your help with troubleshooting
Let me do the ability test and confirm
 
Appreciate your help with troubleshooting
Let me do the ability test and confirm
I tested the spark plug ohms as well i tested 5.5 the other 4.5
Also tired to connect them with ziptie but unable to see any spark
Attached mpem picture as well
IMG_8741.jpeg
 

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Also performed ohms test for spark plug clamps reads 5ohms and with sparkplugs 10ohms
You only care about the caps, not cap and plug. I hope you meant 5 kiloOhms or 5000 Ohms. Realistically, it could be that your caps are bad. Do you have the old caps still attaches to the old wires? Have you tested them?
 
It will be 5kohms. I tested with new caps as well that i got with ignition coil they were like 5kohms and 4.9kohms
Earlier i used the old one as they were good fit on sparkplugs removed them and used the new ones
 
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