1996 Mercruiser 5.7LX Alpha Multiple issues!!

[pikeman8]

Re: 1996 Mercruiser 5.7LX Alpha Multiple issues!!

Are you sure this is not a thunderbolt V? It says thunderbolt V right on the cowling
with the serial number. Any way
to confirm it's not the V?

 

[NHGuy]

Re: 1996 Mercruiser 5.7LX Alpha Multiple issues!!

Do you find a knock sensor on the engine block? I believe the difference is TB V has the sensor with anti detonation control. If you don't you may need to also reset the timing without grounding the purple wire.
I plugged your serial number into a parts lookup, didn't see a sensor. But it doesn't say TB IV vs TB V either.
aChris is pretty knowledgeable, I believe him.

 

[sparky774]

Re: 1996 Mercruiser 5.7LX Alpha Multiple issues!!

you need to rebuild your carb man

 

[John_S]

Re: 1996 Mercruiser 5.7LX Alpha Multiple issues!!

If it is T5, the 5.7LX would have a knock module and knock sensor. There are numerous T5 models that don't have them, though.

 

[achris]

Re: 1996 Mercruiser 5.7LX Alpha Multiple issues!!

Are you sure this is not a thunderbolt V? It says thunderbolt V right on the cowling with the serial number. Any way to confirm it's not the V?

When I put your serial number in to the parts program it only showed a Thunderbolt IV ignition system on the breakdown, no TBV, but if it says ThunderBolt V on the engine cowl I would check to see if it really is, or someone has just put a newer model cover on.

To check what ignition system it has look at the distributor. If the ignition amplifier has a connector with 5 wires, it's a TB IV. The TBV without knock sensor has 8 wires running into the amplifier, if it has the knock sensor it has a piggyback on that with 4 wires running into it. One other option, but it was for older engines (yours shouldn't have this) is that the ignition amplifier is mounted on the port exhaust elbow, that will be a TB IV.

HTH,

Chris......
(or just post a photo of the dissy and we can tell you )