4.3 GL Timing Problem

[Jprevat]

I can not get my timing down to 1* BTDC. I allowed the engine to warm up and inserted the shunt to try and make sure my timing is good but if i take it down below 8* It begins to lug and shuts off. If I get it down to 1* and pull the clip on the shunt before it kills the engine it will idle and run but it is rough.

What am I missing? I have all new plugs in a new engine. At 8* I am able to run it reliably but I am using 91 Octane. My internals are all aligned correctly as well.

Thank you all in advance once again. I hope I can get this figured out once and for all so I can have a reliable boat again and stop bothering yall so much.

 

[Dave-R]

Are you sure you want to take it 1deg. For some reason I'm thinking 8-10 deg. is where it should be in the maintenance mode. and when you are done, and pull the shunt off it goes where it wants to. I'll try to find the procedure again. Dave-R

 

[bruceb58]

1 degree is the correct spec when in base mode.

 

[Jcris]

What would cause it to not "see" base mode?

 

[RCSConstruction]

How far off were you and did you adjust carb with the old timing?

 

[bruceb58]

Describe your procedure for setting base timing. For example, when you put in the shunt.

You should start engine
Put in Shunt.
Adjust timing
Stop engine
Remove Shunt.

Then start and observe timing and make sure it advances.

 

[Jprevat]

I did not adjust my carb at all from my previous engine.

bruceb, I didnt know to pull the shunt after I have killed the engine.

My procedure went,
Start engine, allow to warm above 140, plug in shunt and connect to pos jumper (at this point the engine slows), adjust timing, remove shunt (engine then speeds up)

Could this possibly be spark quench? I set a plug on the block, and even though I was hearing a healthy pop, I was only seeing a yellow orange spark.

My distributor cap has bad looking internal points so I have new vp unit on the way, along with a new rotor.

 

[bruceb58]

What plug are you using?

 

[Jprevat]

Im using the recommended ACDelco MR43LTS plugs. Thats what is listed above my engine harness plug so thats what I replaced the autolites that were in there with.

 

[bruceb58]

Yep...those are correct.

 

[Jprevat]

Hmm... Im thinking I may have a misfire that is causing it to stumble so I will chime back in once the cap and rotor are installed and see if anything changes. Looks like Friday will be my delivery date.

 

[Jprevat]

I have been getting strange readings and random pegging out from my rpm gauge too. Could that be a sign of a bad coil?

 

[bruceb58]

I have been getting strange readings and random pegging out from my rpm gauge too. Could that be a sign of a bad coil?

It's possible but I have the same issue with my tach and its definitely the tach itself.

 

[Jprevat]

My fuel gauge just bit the dust so I wouldnt be too surprised if my Tach s on the way out too. I was reading that the coil on these engines isnt the problem 99.9% of the time so I will just have to see where I am after the new parts and go from there.

 

[Jprevat]

Ok so I have the new cap and rotor on there and I was able to time it down to 1* so it looks like I got that managed.

 

[Jprevat]

I do have a new issue though. I can not start the engine without giving it some throttle in neutral. Im guessing i need to adjust the carb somehow? But Im not sure what to do. One day I will have this thing right. lol

 

[RCSConstruction]

I do have a new issue though. I can not start the engine without giving it some throttle in neutral. Im guessing i need to adjust the carb somehow? But Im not sure what to do. One day I will have this thing right. lol

On just a cold start, or all the time?

 

[Sunken Ship]

What year?

 

[Jprevat]

It looks like on a cold start. Its a 1997 but I think I have it figured out. I just need to advance the throttle down a couple of times and back to neutral before I turn it over and it seems to fire right up.