1997 Ford Ranger 4.0 liter OHV cylinder leak down test. Help, please?

[seanagins]

I am working on a 1997 Ford Ranger XLT 4.0 liter OHV engine and trying to perform a cylinder leak down test on each cylinder. I have the firing order for my engine as, 1-4-2-5-3-6.

Compression readings from the compression test were the following:

Cylinder 1 175psi
Cylinder 2 170 psi
Cylinder 3 165 psi
Cylinder 4 150 psi
Cylinder 5 175 psi
Cylinder 6 165 psi

I am just trying to run a cylinder leak down test on each cylinder. I believe I can find cylinder one TDC, easily, but I get lost from there... Should I just simply count four notches on the harmonic balancer to get to cylinder 4 TDC from TDC of cylinder 1?


Suggestions? Thoughts? Recommendations?

 

[franklin2]

Mark the balancer off in thirds. 3 marks evenly all around the balancer.

Turn the engine to #1 TDC compression stroke. Then turn the engine 1/3 turn, that will be 4. 1/3 more is #2. 1/3 more you will be back on the TDC mark, but that will NOT be #1 firing, it is now #5. 1/3 more is #3. 1/3 more is #6. 1/3 more and you are back to #1 TDC.

 

[seanagins]

Mark the balancer off in thirds. 3 marks evenly all around the balancer.

Turn the engine to #1 TDC compression stroke. Then turn the engine 1/3 turn, that will be 4. 1/3 more is #2. 1/3 more you will be back on the TDC mark, but that will NOT be #1 firing, it is now #5. 1/3 more is #3. 1/3 more is #6. 1/3 more and you are back to #1 TDC.

How do I know which is which if I am just using the 0 mark on the harmonic balancer for finding cylinder 1 TDC versus cylinder 5 TDC?

 

[franklin2]

How do I know which is which if I am just using the 0 mark on the harmonic balancer for finding cylinder 1 TDC versus cylinder 5 TDC?

You take #1 sparkplug out. Then while you get someone to slowly turn the engine by hand the proper direction, have your thumb over the #1 sparkplug hole. When air starts trying to blow your finger off the hole, look down at the balancer, the 0 mark coming up will be the correct one. If it comes around and it doesn't blow your finger off the hole, that is the exhaust stroke and the exhaust valve will be open when TDC comes around.

 

[seanagins]

You take #1 sparkplug out. Then while you get someone to slowly turn the engine by hand the proper direction, have your thumb over the #1 sparkplug hole. When air starts trying to blow your finger off the hole, look down at the balancer, the 0 mark coming up will be the correct one. If it comes around and it doesn't blow your finger off the hole, that is the exhaust stroke and the exhaust valve will be open when TDC comes around.

Thank you!

 

[alwaysFlOoReD]

You take #1 sparkplug out. Then while you get someone to slowly turn the engine by hand the proper direction, have your thumb over the #1 sparkplug hole. When air starts trying to blow your finger off the hole, look down at the balancer, the 0 mark coming up will be the correct one. If it comes around and it doesn't blow your finger off the hole, that is the exhaust stroke and the exhaust valve will be open when TDC comes around.

^^^ yes.
You'll be pulling all the sparkplugs anyway, you an use the thumb system on each cylinder to be sure its at tdc.

 

[seanagins]

^^^ yes.
You'll be pulling all the sparkplugs anyway, you an use the thumb system on each cylinder to be sure its at tdc.

Have all spark plugs removed for cylinder leak down test?

 

[seanagins]

^^^ yes.
You'll be pulling all the sparkplugs anyway, you an use the thumb system on each cylinder to be sure its at tdc.

You take #1 sparkplug out. Then while you get someone to slowly turn the engine by hand the proper direction, have your thumb over the #1 sparkplug hole. When air starts trying to blow your finger off the hole, look down at the balancer, the 0 mark coming up will be the correct one. If it comes around and it doesn't blow your finger off the hole, that is the exhaust stroke and the exhaust valve will be open when TDC comes around.

I am a one man operation, currently. Is there a way I rig up my compression gauge without the schrader valve in to signify when I am at TDC by psi reading on gauge?

 

[alwaysFlOoReD]

You can do one at a time, or all at once.

 

[alwaysFlOoReD]

I am a one man operation, currently. Is there a way I rig up my compression gauge without the schrader valve in to signify when I am at TDC by psi reading on gauge?

You should be able to, but finger is quicker. Also, a momentary switch from battery positive to the solenoid (relay) small terminal will work for bumping the motor. Pull the fuel fuse. Key off.

 

[Josh B]

How about a wood dowel in the spark plug hole, would that stop it at top?

 

[RonD]

I am a one man operation, currently. Is there a way I rig up my compression gauge without the schrader valve in to signify when I am at TDC by psi reading on gauge?

Don't need to change anything on the pressure gauge, or even use the pressure gauge
Remove all 6 spark plugs so engine is easy to turn manually
Put gauge in spark plug hole of the cylinder you want to find TDC compression stroke

Turn engine/crank shaft clockwise(facing front of engine) until gauge starts to register and YOU FEEL resistance, turn it about 1/4 turn more, both valves are now closed
If you want exact TDC then pull out the gauge and put a screw driver/stick down the hole and move the crank back and forth until piston is at TDC by feel

Without the gauge just put a spark plug back in the hole, finger tight
Turn crank until you FEEL the resistance, its obvious, 1/4 turn more, then "fine tune" with screwdriver or stick

 

[franklin2]

How about a wood dowel in the spark plug hole, would that stop it at top?

You haven't had the Eureka moment yet. These are 4 cycle engines, the piston comes to the top twice during one complete cycle. So yes, you can use a wooden dowel to see if the piston is at the top, but you have a 50% chance of being wrong, since it also comes to the top on the exhaust stroke. You can pull a valve cover and look at the valves and make sure they are closed when the piston comes to the top, that would be firing tdc, but on these engines it's such a pain to pull the valve cover, it's easier to do it the other way.

I would thing the compression gauge idea would work.