My Willys 3A and 3B Community
TECH FAQ SECTIONS => Engine compartment => Topic started by: BillT on February 17, 2019, 09:18:21 PM
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I have one cylinder not firing correctly. When I pull ignition wires, one at a time, 1,2, and 4 the engine nearly dies. When I pull wire no. 3 there is no change in engine sound, and the spark is weak. Pulled the plug, heavy carbon on it but that isn�t unusual for this engine. Installed a new plug and swapped ignition wires, still missing. Checked the distributor, everything looks good, points at .020�. No tracking or carbon in there. The PO had installed a IAT-4405 vacuum advance distributor,� but the vacuum was never connected, engine seemed to run ok.
Next I checked compression, have 117 dry and 127 wet. Engine intake manifold pressure is 19.5� at an idle of 700 rpm
The engine has an intake manifold leak, detected by carb spray, on the section of the manifold in front of cylinder #3.Could this be the problem?
The carb has been changed from a Solex to a Carter WO 636SA freshly rebuilt by Old Jeep Carbs.
The ignition wires are the new style, not copper, they will be changed. As well as a IAD-4008 distributor will be installed.
So what am I missing here? Sure could use some ideas or thoughts.
Added info- this is a 1952 CJ3A with the standard L-134 engine. I have owned since this past spring. The engine has been in the Jeep since 1955 at least, probably the original engine. I have no history of any kind on this Jeep.[reason]Add info[/reason]
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"The engine has an intake manifold leak, detected by carb spray, on the section of the manifold in front of cylinder #3. Could this be the problem?"
Yes.
"The PO had installed an IAT-4405 vacuum advance distributor, but the vacuum was never connected, the engine seemed to run ok."
Won't hurt to connect to vacuum at the base of the carb.
Start there.
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Thanks Rick, I have about given up on the manifold on this engine. I have a spare engine and will pull the manifold from it and give it a try.
I also have a spare distributor and will try it if no favorable results with the manifold.
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If the spark is week try a different distributor cap and the spark plug wire from cap to plug. Easy things first.
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Thanks Rick, I have about given up on the manifold on this engine. I have a spare engine and will pull the manifold from it and give it a try.
I also have a spare distributor and will try it if no favorable results with the manifold.
Easier if both manifolds are off. Mate the two on the bench, stretch a straight edge across the length of the pair from ear to ear to check for mismatched gaps that may need some machining to make them all straight and level.
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64cj5 thanks for the help but I tried that Saturday, no change. More thoughts are welcome.
Rick I had done that with the current manifold, machined and all. After that failed I pulled it back off and sprayed copper sealant on the manifold to block gasket and the gasket between the two manifolds. No change
I have ordered a set of copper core plug wires and a new gasket kit. Probably be here by the end of the week.
I may go ahead and stick the other distributor in to see what change that makes. I'm thinking about a new coil but I hate to just throw parts at it for a repair, I didn't do that when I got paid for working and don't want to do it now.
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Thursday I pulled the manifold from the donor engine. This is some kind of a commercial engine, welder, or compressor, etc. Soaked it a good 24 hrs in diesel fuel. Due to the condition of the four bolts securing the two manifolds I did not separate them to change the gasket. Changed everything out and guess what? No more leak!!! Cylinder no.3 is firing, exhaust no longer putt putts. Yea! Time for a cold beer, or four, after all it�s Saturday.
But all is not good. The exhaust pipe to manifold, the blind bolt hole, stripped out. It�s not leaking for now but it�s only a matter of time. Only in a Jeep...... oh hell ..... I luv�em.