1999 Tige 5.7 mercruiser no spark

[joshe08]

I have 12v at coil with key on.. I can ground the neg. side of the coil and get spark out of the coil with the neg wire not connected.. so not the coil.. might be the dist sensor but not sure how to check it.. it's a 2 wire.. any help thanks

 

[John_S]

Re: 1999 Tige 5.7 mercruiser no spark

Go to the Adults Only Thread --> Mercruiser Service Manuals --> Download #24
http://forums.iboats.com/showthread.php?p=1693398#post 1693398

Read Thunderbolt V section and follow diagnostic path.

 

[zbnutcase]

Re: 1999 Tige 5.7 mercruiser no spark

The dist sensor does fail quite often, in my experiance far more often than the module does.

 

[joshe08]

Re: 1999 Tige 5.7 mercruiser no spark

thanks for the info on the manual.. I will check the dist sensor and get back to you.. if it checks out ok.. what dirrection should I go next?? will a different sensor cause no spark?? I want to rule out all possibilities before I go to the ECM. very expensive

 

[Don S]

Re: 1999 Tige 5.7 mercruiser no spark

if it checks out ok.. what dirrection should I go next??

Once you download the manual, it will tell you that to. Just remember, you have to read the manual after you download it. Section 4B covers the ignition.
Now, if you have EFI, that changes everything. That is why I always ask for Merc serial numbers. Then there isn't a question about year (Usually different than boat) or other information. Like drive, EFI, carbed, etc.

 

[joshe08]

Re: 1999 Tige 5.7 mercruiser no spark

it is a EFI system!!

 

[Don S]

Re: 1999 Tige 5.7 mercruiser no spark

it is a EFI system!!

WE need the serial number.

 

[joshe08]

Re: 1999 Tige 5.7 mercruiser no spark

there are 2 sets of numbers L305478 and sav cert. M146519709

 

[Don S]

Re: 1999 Tige 5.7 mercruiser no spark

You have an MIE (Inboard) 350Mag MPI, Tournement Ski Gen+ engine with an MEFI3 ECM. You have the Thunderbolt ignition, but only 2 wires going to it, and they go to the ECM.

I would suggest you download manual 24, you can get it HERE

The wiring diagram on page 5G-20 shows a partial wiring diagram for your engine and distributor.

 

[joshe08]

Re: 1999 Tige 5.7 mercruiser no spark

thanks Don.. I'm gonna Jack with it tomorrow after work.. hope its not an ECM!! I will get back to you tomorrow.. thanks again

 

[joshe08]

Re: 1999 Tige 5.7 mercruiser no spark

I went through the flow chart on ignition check.. it's said to unplug the purple wire on the dist sensor and ground it with the key on.. I did that and got the coil to fire.. turned out to be the dist sensor.. goin to get one today.. thanks for the help.