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Showing results for tags '4.2l'.
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For finding TDC on the compression stroke without the starter functioning, a time-honored approach is a whistle that fits into the spark plug hole for #1 piston. Spark plugs removed to ease crankshaft rotation, this device allows rotating the crankshaft by hand in the normal direction of rotation while listening for the whistle as the piston rises on the compression stroke. Note: If you have brazing or soldering equipment, you can make this tool using an old spark plug shell with the porcelain, electrode and ground strap removed. Braze or solder a metal whistle to the metal plug shell. Remove any burrs or debris from the "tool", then thread it into the spark plug hole for #1 plug in this case. For a pre-made type, here's a popular and inexpensive example that uses a rubber stopper instead of a threaded base. You'll get the idea: https://www.amazon.com/Innovative-Products-7894-Flexible-Compression/dp/B000TQ16HG. An alternative is to use a compression gauge installed in #1 cylinder spark plug hole. Plugs removed, rotate the crankshaft and watch for the bump in compression as the piston rises on the #1 compression stroke. Simultaneously watch the crankshaft damper timing mark to make sure you're rising to #1 TDC. Once the piston is at TDC (look down the #1 spark plug opening and confirm that the piston is at its peak with the TDC mark aligned on the crank pulley/damper), you can decide where you want to place the #1 spark plug wire in the cap rotation. Allow enough room for the distributor's vacuum canister to rotate back and forth without interference when you set the spark timing. Lift the distributor away from the camshaft drive to align the distributor shaft and rotor with a selected distributor cap position for the #1 spark lead. Then you can hook up the remaining spark leads in clockwise rotation, following the firing order: 1-5-3-6-2-4. There is a preferred position for #1 wire in the cap, traditionally around the 5:30 to 6-o'clock position on a CJ Jeep inline six. Without EFI and using a conventional HEI/DUI distributor like you're doing, you can select whatever cap position you want for #1 wire lead. Just make sure the rotor points to that position at TDC for #1 piston on the compression stroke. Allow enough room for distributor movement to fine tune the spark timing. Install spark leads following the 1-5-3-6-2-4 Jeep inline six firing order. Moses -
Hi, I've been dealing with an overheating behavior in my YJ 1989 Wrangler (4.2L with all emissions control hooked up except pulse air system, Carter BBD, Auto Trans). Long time ago I've replaced cooling fluid, It was 100% tap water that is the worst choice due to corrosion; so I decided to replace it by an ethylene glycol mix as you can find them ready to pour into your cooling system. I don't know if the coolant was poor quality but immediately after replacing the fluid I was getting the engine overheated. Perhaps it was air trapped in the system as the guy replacing the coolant did all the procedure really quick with the engine still warm... Well I had to go back to water again and the issue was solved. No more overheating during next days. Then I went wheeling several months after, when stopped the vehicle heared something like a pressurized air leak, it was the hose from the thermostat housing to the intake manifold, was cracked and ended up blown after I pulled it. So I shortened the hose and reinstall it again. Got home with overheating issues again. Bought all new hoses, including upper and lower radiator hoses. Heater was disabled so former owner plug the nipple coming from the water pump and the one on the back of the intake manifold as well, I didn't enable the heater yet but I have connected a hose between those two points to keep coolant flow through the manifold and cylinder head. Found that there was no thermostat installed, so installed one. Inspected water pump, a little bit of corrosion but the rotor and impeller was good, no play at the shaft. Refilled all the system with 50/50 mix and have to add some distilled water as I got short of coolant to top up the radiator. Fan clutch was replaced as well. I've been having random overheating, it is worst when A/C is turned on, obviously because the condenser is in front of the radiator. But sometimes runs good and the needle does not go above 210. I do not know where the needle it is supposed to be when the cooling system is working as it should. There are sometimes that random misfiring is happening, not too critical but I'm sure I'm not getting a perfect tuned engine. I've replaced the radiator cap just to discard this is the troublemaker. (13lb new one installed) Does the water to coolant swap have something to do with making debris and metal corrosion to become loose and start building a sediment inside the engine's block?
