Started out as a good day on the water. 4.3 mercruiser

[Scott06]

Why would you replace the ignition system if it’s working? The atB is a great system until the ignition module needs to be replaced $$$. Then typical replacement is a delco est. this isn’t any better except module rEllacement cost. Both are OEM quality systems.

friggin auto correct...

I meant the Merc TB (thunderbolt) is a great system, Merc just screws the owner by NLA or insane ignition module prices... so when the module dies a actual Delco Est (not cheap knock offs) is a good relatively drop in replacement.

Thanks everyone, I will keep everything intact as of right now. I will still order the 3 wire trigger, cap, rotor to keep on the boat as they are easy enough to change on the water if needed. I was hoping to go out again this weekend but the weather is not looking to great.

Yes the trigger sensor is not a bad replacement or keep one in the boat. Also keep a cap and rotor. I had to chisel my rotor off when I replaced it, so likely if you have to replace the trigger likely you will waste the rotor

 

[Lou C]

Why in the world does Merc seem to glue on those rotors? Talk about making a simple job a headache!
I’m curious how reliable the aftermarket modules are for the EST system are. It doesn’t sound like there’s a widespreaad problem so maybe it’s not a complex component to reproduce.

 

[Pmt133]

I don't know about the EST but I can say aftermarket HEI modules are typically ****.

 

[Lou C]

this is what I hear all the time in the Jeep world, aftermarket sensors, etc the only ones with decent reliability seem to be NTK, (crank sensors and O2 sensors) perhaps Standard Motor Products.....

 

[Scott06]

Why in the world does Merc seem to glue on those rotors? Talk about making a simple job a headache!
I’m curious how reliable the aftermarket modules are for the EST system are. It doesn’t sound like there’s a widespreaad problem so maybe it’s not a complex component to reproduce.

It seems to be hit or miss with the est modules , also finding an actual delco est is not as easy anymore. Mich Motorz no longer carries actual Delco for the 4.3 and 5.7, only the 3.0. When I bought my repower partial engine from them in 2015 they normally supply them with the EST. I had them sub a TB so I could keep it stock merc. I did buy two used modules on ebay. Only time i used the spare was when my kill switch acted up. Swapped the module to see if I got spark back.... then realized I just needed the cycle the kill switch...

 

[Pmt133]

the other thing with the GM HEI modules is that a lot tended to have specific quirks for their application. Latency comes to mind and a lot of aftermarket ones I've used and tuned on the 84 needed some massaging to work as well as the stock module in the spark tables.

 

[Newbie@boats]

wea

friggin auto correct...

I meant the Merc TB (thunderbolt) is a great system, Merc just screws the owner by NLA or insane ignition module prices... so when the module dies a actual Delco Est (not cheap knock offs) is a good relatively drop in replacement.


Yes the trigger sensor is not a bad replacement or keep one in the boat. Also keep a cap and rotor. I had to chisel my rotor off when I replaced it, so likely if you have to replace the trigger likely you will waste the rotor

Is the ignition module the black box next to the distributor?

Do you have a link for a replacement Delco Est incase I run into issues with that module failing?

 

[Scott06]

wea

Is the ignition module the black box next to the distributor?

Do you have a link for a replacement Delco Est incase I run into issues with that module failing?

The TB module is either mounted to the dist or on the exhaust elbow. Both are black boxes, sometimes with a knock module.

just google 4.3 delco est. there are original Delco units and aftermarket knock offs. Sierra has units that are considered good.
if I was in your shoes I would look for a used module on ebay. That is the only part that would make me replace the TB. I got a spare for $200 a few years back, which probabky ensures I will never need it

 

[Newbie@boats]

Just wanted to provide an update :

Took the boat to the lake today and it would crank and not start. Getting extremely fustrated and almost giving up it finally dawned on me……….the lanyard switch was in the off position

After feeling incredibly stupid for not checking that first the boat fired right up and ran excellent all morning. Starting and stopping at a few fishing spots-no issues.

Thanks again for the help

 

[Scott06]

Just wanted to provide an update :

Took the boat to the lake today and it would crank and not start. Getting extremely fustrated and almost giving up it finally dawned on me……….the lanyard switch was in the off position

After feeling incredibly stupid for not checking that first the boat fired right up and ran excellent all morning. Starting and stopping at a few fishing spots-no issues.

Thanks again for the help

we have all been there.

A few years back my then 13 or 14 year old was taking jetski out with her friend, one of first times she was out by herself. There were a lot of boats out this day, so I went out in the boat and from a distance just kept an eye out. Went over a hard wave and engine cuts out, wont would catch during cranking then die ... I have my daughter tow me in only to figure out there is no spark due to the kill switch.