THUNDERBOLT V, without a knock sensor

[dead boat]

I have a 5.7, 1996 thunderbolt V, and I cant find the knock module, no wiring harness, nothing is there. Is this not on all t-bolt V's, or could it be mounted in an other location, not behind the distributor? The repair book shows it, the engine cove says it is a thunder bolt V and it is carburetor.

 

[Don S]

Re: THUNDERBOLT V, without a knock sensor

What is the Merc SN of your engine, and how sure are you that it's a TB5 and not a TB4? If you are going by the year of your boat, the year of the engine may be older. Not an uncommon thing with boats.
That is why you go by SN only. Not year, untill you know the year of the engine for sure.

 

[dead boat]

Re: THUNDERBOLT V, without a knock sensor

Don,
The engine serial # 0f787508.

 

[Don S]

Re: THUNDERBOLT V, without a knock sensor

It should have one, and the module should be mounted on the distributor like this.

The knock sensor is just in front of and above the starter, like this.

If not, post a picture of what you have.

 

[dead boat]

Re: THUNDERBOLT V, without a knock sensor

The file size is to big to upload on the pics. I have the exact same control module shown on you image and in the book, with no knock control module and where the knock sensor should be I have a plug/ bolt installed

 

[jtybt]

Re: THUNDERBOLT V, without a knock sensor

It's important to check for the knock sending unit where Don showed you. The TB V ignition system basically advance the timing until it 'hears' a knock(detonation) and backs off the timing. Without the knock sensor, you will destroy the engine from detonation

The TB IV has a different ECM which have set timing curves.

 

[dead boat]

Re: THUNDERBOLT V, without a knock sensor

I called mercruiser, the nice lady told me the 2 barrel carb is a modal 5.7 alpha, it dosent have a knock module. The 5.7 LX does with a 4 barrel carb. I think my next step is to check my fuel mixture screw.

 

[Bondo]

Re: THUNDERBOLT V, without a knock sensor

I called mercruiser, the nice lady told me the 2 barrel carb is a modal 5.7 alpha, it dosent have a knock module. The 5.7 LX does with a 4 barrel carb.

Ayuh,.... I've seen them both With,+ Without,... Never knew Why though....

Personally, I love the Simplicity,+ Reliability of the T-Bolt IVs myself....

 

[bruceb58]

Re: THUNDERBOLT V, without a knock sensor

I called mercruiser, the nice lady told me the 2 barrel carb is a modal 5.7 alpha, it dosent have a knock module. The 5.7 LX does with a 4 barrel carb. I think my next step is to check my fuel mixture screw.

And you believe her? What are you thinking? Just kidding of course.

Your fuel mixture screw will have nothing to do with this and only adjusts mixture at idle.