Coloeman 2500--- no spark to plug,, plenty oil

Not sure if you mean engine will not turn at all (locked) or engine will not start. The engine may have been on its side causing this condition. Clean carb and filter of excess oil. Remove spark plug and clean cylinder and plug of oil that may have entered causing locked condition. Replace oil lost from crankcase. With spark plug removed and kill swith on off, pull rope to blow out oil and verify that motor will now turn. If it still does not turn could be lock rod to crank or faulty pump. If engine had very little or no oil in crank and was run, suspect locked crank, however if your engine has oil senser, this condition would have prevented engine from starting. If you mean that engine will not start, low oil senser most likely preventing start due to low oil. Good luck

Engine Cranks But Will Not Start Basic Checks:
A. Test Fuses. Test both under hood power distribution center and the fuse panel under dash. This is done with a test light tool. The test light should illuminate on both sides of the fuse, if not the fuse has failed and needs to be replaced.

B. Testing Fuel Pressure Test for proper fuel pressure with a test gauge on the fuel rail, most throttle body injection cars (TBI) are between 13 psi and 17 psi. and most (DPI) direct port inject systems are between 40 psi and 55 psi. If no or little fuel pressure is observed and there is 12 volt power present the fuel pump, the fuel pump needs replacing.

C. Checking Timing Belt Test for compression by removing a spark plug and insert a compression gauge. Crank the engine over about 5 seconds the gauge should read between 125 psi and 165 psi, if no compression is observed remove front engine cover to inspect timing belt or chain. Crank engine to observe cam rotation, if the cam does not rotate the timing belt or chain has failed. (note: if the timing belt drives the water pump it is best to replace the water pump at this time)

D. Test for Injector Pulse Remove injector connector to insert injector test light (node) or volt meter. Observe light flash or gauge pulse while cranking. If light/voltmeter doesn't respond, an ignition distributor/crank angle sensor (CKS) or an ignition module is most likely your problem.

E. Test for Ignition Spark Remove spark plug wire, insert an extra spark plug into end of wire, rest spark plug next to a ground source then crank engine. You should observe a blue spark between the spark plug gap and ground source. If no spark is observed, an ignition coil, ignition rotor or spark plug wires might have failed. (always keep hands away from engine when cranking)


The ENGINE CROSS-SECTION below (typical 'V-8' ENGINE) shows all main ENGINE components and indicates the exact location of the most HEAT DAMAGE PRONE PARTS - THE HEAD GASKETS.

remove the spark plug and wile holding with a pair of pliers
ground the metal side of the plug against the top of the motor on a bare spot
set the run switch to run and crank the engine look for a spark if theirs a spark
re install the plug.
check the gas line at the carb by removing the
hose and turning on the gas valve under the tank.
if gas flows then replace the hose back.
if theirs no gas then you have a plugged fuel line or gas valve
their is also a screen in the tank attached to the valve remove it and install a in line filter
it will be easier to replace later if it happens again.
remove the air filter and crank engine with the choke closed
check for a gas smell in the carb hole by smell after cranking engine.
if wile checking for a smell of gas at the carb and their was none then you can have a stuck float or
gummed up carb remove and dissemble clean and at that point rebuild the kits are only around $20.00 and a float $6.00+.
if ok remove the spark plug again and set run switch to off
place a finger over the plug hole crank finger should be blow-en from the hole
and a wosh of air if ok. go to next step.
if the pressure did not blow your finger off you may have a stuck valve or a bent one
this will require removing the head for repairs.
take in for service.
if there is no spark with plug removed remove wires from the run switch and connect
together and remove wire from the low oil sensor crank. if spark replace the wire back
on low oil sensor crank if no spark replace the low oil sensor reassemble run.
if the is no spark with the wire on the sensor then replace the run switch.
re assemble run. if their is no spark with oil sensor disconnected and run switch wires
connected to each other remove the front air flow cover to expose the coil check wires for any
bare spots repair as needed. on the top on the flywheel theirs a coil their will be a spade plug
or a wire small that is a kill wire disconnect and crank check spark if spark then that wire is shorted
in the loop and you have to trace it it will go to a wire stud mounted to a plate under
the carb with a plastic mount this can be cracked and shorting bypass and try again still
no spark use a match book cover and lower the coil to the flywheel with the match book cover
in be tween and disconnect the small wire crank if no spark the coil unit is the issue replace
some people will say sand clean the tops of the magnets built in to the flywheel this is a myth
it don't matter but feel free to clean anyways it don't hurt.
this seams allot but it is a complete diagnoses the fuel,spark and air system if all this is ok and still don't run you have a serious internal issue the engine will either need
major work or replacement. i hope this all helps you.

if it turns very freely then it can be a stuck opened valve as well check for spark by removing the plug and wile still with the wire plugged in ground against the case wear gloves or use insulated pliers crank the engine look for a spark have the kill switch turned to the run setting in so then check the gas make sure the carb is getting gas if been sitting it may need to be cleaned do to old gas shalac or stuck if there is no spark you may have a bad coil or a kill wire grounding out witch will not allow a spark remove the front pull starter cover to expose the flywheel and check the wires for shorting or a bare one tape or wire crimp for a repair older engines had a points there under the fly wheel and then it will have to be removed for servicing you can check for compression as well by pluging spark plug hole with finger just cover it and crank it should blow your finger off the hole and make a load air wish sound if not you have ether a hole in piston or bad or stuck valve if all this is ok you might have a low oil sensor that's bad check oil and fill as needed if low if good then it should be a 1 wire sensor remove the wire and crank see if there is a spark if there is then that unit needs replacing you can run the engine with out that low oil sensor but you must check it often and tape up the wire so it is not grounding out hope this helps

remove the spark plug and wile holding with a pair of pliers
ground the metal side of the plug against the top of the motor on a bare spot
set the run switch to run and crank the engine look for a spark if theirs a spark
re install the plug.
check the gas line at the carb by removing the
hose and turning on the gas valve under the tank.
if gas flows then replace the hose back.
if theirs no gas then you have a plugged fuel line or gas valve
their is also a screen in the tank attached to the valve remove it and install a in line filter
it will be easier to replace later if it happens again.
remove the air filter and crank engine with the choke closed
check for a gas smell in the carb hole by smell after cranking engine.
if wile checking for a smell of gas at the carb and their was none then you can have a stuck float or
gummed up carb remove and dissemble clean and at that point rebuild the kits are only around $20.00 and a float $6.00+.
if ok remove the spark plug again and set run switch to off
place a finger over the plug hole crank finger should be blow-en from the hole
and a wosh of air if ok. go to next step.
if the pressure did not blow your finger off you may have a stuck valve or a bent one
this will require removing the head for repairs.
take in for service.
if there is no spark with plug removed remove wires from the run switch and connect
together and remove wire from the low oil sensor crank. if spark replace the wire back
on low oil sensor crank if no spark replace the low oil sensor reassemble run.
if the is no spark with the wire on the sensor then replace the run switch.
re assemble run. if their is no spark with oil sensor disconnected and run switch wires
connected to each other remove the front air flow cover to expose the coil check wires for any
bare spots repair as needed. on the top on the flywheel theirs a coil their will be a spade plug
or a wire small that is a kill wire disconnect and crank check spark if spark then that wire is shorted
in the loop and you have to trace it it will go to a wire stud mounted to a plate under
the carb with a plastic mount this can be cracked and shorting bypass and try again still
no spark use a match book cover and lower the coil to the flywheel with the match book cover
in be tween and disconnect the small wire crank if no spark the coil unit is the issue replace
some people will say sand clean the tops of the magnets built in to the flywheel this is a myth
it don't matter but feel free to clean anyways it don't hurt.
this seams allot but it is a complete diagnoses the fuel,spark and air system if all this is ok and still don't run you have a serious internal issue the engine will either need
major work or replacement. i hope this all helps you. re-post your outcome please.

If it sat for 2 years, particularly in humid environment, try removing one of the wires on the back of the OFF / Shutdown switch. If you get spark then, the switch is defective. Also check the wiring closely as a pest may have been gnawing on the wire itself.

The oil alert will also cause the ignition to be disabled. Removing the wire from the sensor will temporarily defeat its intended purpose of shutting down the engine due to no / low oil. If the engine runs afterwards, then you may have a bad sensor if the crank case has adequate oil.

Check for spark at the spark plugs. If no spark, remove distributor cap and inspect the inside of the cap and the rotor for obvious signs of wear or damage. Check for spark at the coil wire by removing the coil wire from the center of the distibutor cap, and, holding the end of it close to the engine block, have someone crank the engine. There should be a very strong spark. If there was spark at the coil but not at the plugs, replace the distributor cap and rotor. If there is no spark at the coil, you either have no power or ground at the coil, or the coil is bad. With the ignition ON, there should be 12v at the red wire for the ignition coil. if not, check the fuses. Check for the pulsing ground signal of the ignition coil at the other wire ( I think a white wire) using a test light clipped to battery + while the engine is being cranked. If there is no light, the problem is likely the ignition module or pick-up coil, which is located in the distributor. Make sure that the wiring and connections are in good shape for these items before condemning them.
Pick-up coil should have about 1500 ω of resistance.
Good Luck

Hi disconect all wires going to the coil that feeds the plug ( oil switch & stop switch.
With plug grounded turn engine over to see does the plug spark.
If not try again with new plug.
If it still does not spark replace the coil unit as it either has a faulty coil lead or coil itself is faulty.

Engine Cranks But Will Not Start

For an engine to run, you need three things to happen inside the engine. Compression, fuel and ignition, without any one of these components the engine will not run.
Basic Checks:

A. Test Fuses. Test both under hood power distribution center and the fuse panel under dash. This is done with a test light tool. The test light should illuminate on both sides of the fuse, if not the fuse has failed and needs to be replaced.
B. Testing Fuel Pressure Test for proper fuel pressure with a test gauge on the fuel rail, most throttle body injection cars (TBI) are between 13 psi and 17 psi. and most (DPI) direct port inject systems are between 40 psi and 55 psi. If no or little fuel pressure is observed and there is 12 volt power present the fuel pump, the fuel pump needs replacing.
C. Checking Timing Belt Test for compression by removing a spark plug and insert a compression gauge. Crank the engine over about 5 seconds the gauge should read between 125 psi and 165 psi, if no compression is observed remove front engine cover to inspect timing belt or chain. Crank engine to observe cam rotation, if the cam does not rotate the timing belt or chain has failed. (note: if the timing belt drives the water pump it is best to replace the water pump at this time)
D. Test for Injector Pulse Remove injector connector to insert injector test light (node) or volt meter. Observe light flash or gauge pulse while cranking. If light/voltmeter doesn't respond, an ignition distributor/crank angle sensor (CKS) or an ignition module is most likely your problem.
E. Test for Ignition Spark Remove spark plug wire, insert an extra spark plug into end of wire, rest spark plug next to a ground source then crank engine. You should observe a blue spark between the spark plug gap and ground source. If no spark is observed, an ignition coil, ignition rotor or spark plug wires might have failed. (always keep hands away from engine when cranking)