Coughing 360

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Craigo

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Traverse City, Michigan
Have a '77 360..80k in a sportsman B series van camper.. Just replaced the right bank exhaust gasket.. noticed lots of anti freeze coming from the last rear bolt hole on head when I removed it..is this normal? Secondly..this old beast ran great before I changed this gasket. It still starts fine..but coughs under load now. I completely warmed it up before hitting the road. Here is my list..check gas line, accelerator pump diaphragm, vacuum leak, firing order and timing... Wonder how to test fuel pump. Other than that..dash lights quit..cab overhead light quit. Love the old school stuff..my 16 year old son is diggin it too..
 
Normal on all four corner exhaust studs/bolts for coolant to come out because they are threaded into the water jacket.
Those should be put back in with a sealant on the threads.
"Coughing" has nothing to do with changing exhaust gaskets.
You probably have a cracked vacuum line somewhere, or a carb issue like you posted above.
If it coughs when you are accelerating it could be a bad accelerator pump.
Plugging up filters can cause low fuel levels in the carb and do the same thing.
 
Don't know TB, it IS vaguely possible that the stud is leaking on shutdown, getting coolant down that adjacent exhaust port into a cylinder and fouling a plug, etc

As you say........sealer on the corner bolts/ studs
 
TrailBeast said:
Normal on all four corner exhaust studs/bolts for coolant to come out because they are threaded into the water jacket.
Those should be put back in with a sealant on the threads.
"Coughing" has nothing to do with changing exhaust gaskets.
You probably have a cracked vacuum line somewhere, or a carb issue like you posted above.
If it coughs when you are accelerating it could be a bad accelerator pump.
Plugging up filters can cause low fuel levels in the carb and do the same thing.
Click to expand...
 
Hey TB..thank you for suggestions..just jostling those hoses can crack them..old..will replace. I think there is a rubber lead from the gas line to the tank also. Someone also said rotors are short lived on this engine..thinking about going through the distributor sometime hare..will do your suggestion tonight..will report back..cheers
 
Craigo said:
Hey TB..thank you for suggestions..just jostling those hoses can crack them..old..will replace. I think there is a rubber lead from the gas line to the tank also. Someone also said rotors are short lived on this engine..thinking about going through the distributor sometime hare..will do your suggestion tonight..will report back..cheers
Click to expand...

Whoever said that about the rotors is full of it. :D



67Dart273 said:
Don't know TB, it IS vaguely possible that the stud is leaking on shutdown, getting coolant down that adjacent exhaust port into a cylinder and fouling a plug, etc

As you say........sealer on the corner bolts/ studs
Click to expand...

It's also vaguely possible a golf ball from the nearest golf course bounced in there and plugged the exhaust port when he wasn't looking causing the burned fuel to revert back into the intake, but I doubt it. :D
Feeling particularly smartassist today.LOL
 
Did you pull the plug wires off when you changed the gasket? Possible a couple got swtched around.
 
Wouldn't that be more than 'coughing under load' when the firing order of two plugs was messed up?
 
A buddy's 340 acted the same way after he put headers on. Ran ok but popped and coughed a little under load. Sure enough, 5 and 7 were accidently switched. Glad you got it figured out
 
AJ/FormS said:
You will probably never do that again,lol
Click to expand...
No..I won't.. Like to share something..my son just turned 16.. I include him on repairs..and he loves learning about how old school works.. I tell him..buy an older car..pre processors..carburated..a driver. Cheap to fix..do it yourself. Care for it and it can actually go up or maintain value. Also.. Want to thank everyone who replied..funny how simple it can be.
 
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