Compression Test with Transistor Ignition
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,691
Likes: 206
From: Loveland, CO
Compression Test with Transistor Ignition
I want to run a compression test on my '69 435 horse engine. I remember reading somewhere about how to ground the coil or spark plug wires so as not to damage the system while doing a compression test. I have a TI system and am particularly concerned.
What is the proper method of cranking the engine with all plugs removed? Can you just pull the coil wire and ground it? Or, am I being paranoid and there is nothing to worry about cranking away?
Thanks, Ralph.
PS: I hydraulic locked my engine due to faulty float seats and am hoping for no engine damage.
What is the proper method of cranking the engine with all plugs removed? Can you just pull the coil wire and ground it? Or, am I being paranoid and there is nothing to worry about cranking away?
Thanks, Ralph.
PS: I hydraulic locked my engine due to faulty float seats and am hoping for no engine damage.
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,691
Likes: 206
From: Loveland, CO
Thanks Lars. A leak down test is certainly an option. I feel a lot better because this afternoon I finally got all the gas out of the cylinders and it started up just fine. Seems to run like it always has. So I don't think I did any damage. I can even get the idle to be more adjustable with the new carbs. Secondarys are still unhooked pending adjustment of the linkage.
Gary, thanks for the comment. I guess unplugging the module should work.
Ralph.
Gary, thanks for the comment. I guess unplugging the module should work.
Ralph.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by rponfick
Wally, thanks for the affirmation. I think I dodged the bullet. I will not store car with full tank of gas.
Ralph.
Ralph.
Thread Starter
Drifting
Joined: Nov 2002
Posts: 1,691
Likes: 206
From: Loveland, CO
Bob, I am as confused as you are. On another post relating to this subject, I have had conflicting comments saying the fuel pump can let fuel through and another saying it has a check valve.
All I know is that I stored the Vette in the garage for about a month with a full tank of gas and somehow the cylinders filled up with gas, causing hydraulic lock. The amounts of gas greatly exceeded the fuel bowl capacity, so a large amount of gas got there somehow.
My garage floor has the usual slope toward the door for drainage and I backed the Vette in. It appeared to me that the top of the gas tank could be higher than the carb fuel inlets. Adding to my theory was that gas continued to dribble out of the fuel line after I had disconnected it from the carbs. I thought the dribble was just residual fuel draining from the lines, but it continued. It only stopped after I jacked up the front of the car.
From now on I will drive in the garage front first and not store with a full tank of gas. I do not want to go through this again.
Ralph.
All I know is that I stored the Vette in the garage for about a month with a full tank of gas and somehow the cylinders filled up with gas, causing hydraulic lock. The amounts of gas greatly exceeded the fuel bowl capacity, so a large amount of gas got there somehow.
My garage floor has the usual slope toward the door for drainage and I backed the Vette in. It appeared to me that the top of the gas tank could be higher than the carb fuel inlets. Adding to my theory was that gas continued to dribble out of the fuel line after I had disconnected it from the carbs. I thought the dribble was just residual fuel draining from the lines, but it continued. It only stopped after I jacked up the front of the car.
From now on I will drive in the garage front first and not store with a full tank of gas. I do not want to go through this again.
Ralph.
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