4 Cylinder Gas Engine No Spark- Help, Please

[MossRoad]

I have a 4 cylnder gas engine in my IH2500b. I am getting no spark at the plugs.

I pulled the plug wire that goes between the distributor and the coil off the distributor end and layed it near some bare metal and cranked the engine. Nothing.

I measure 12V from the + terminal on the coil to ground and on the - terminal to ground when the key is in the on position.

I have the ignition side wire going to the + terminal on the coil.

I have the - coil wire going to the distributor.

I've changed the coil and still have no spark coming out of the coil and all the same measurements as listed above.

Any suggestions would be greatly appreciated. Thanks in advance.

 

[Richard]

I'm not a mechanic but if I understand you correctly, you have juice TO the coil and no spark. You then swapped coils, and STILL no spark.

Have you checked your wires to see if you have an internal break in the center coil wire? (coil to dist)

Frustrating I know. Good luck

 

[teddydo]

I am no mechnic, can't even spell it. The input to the coil must pusate via the points or electronics inside the distubter as the cam rotates, meaning you must be trying to start the machine while checking. As for your check, you need to leave the spark plug wire connected to the distrubter cap and hold the other end close to ground to check for spark out of the coil. I'ts very simple and you will get the understanding if you just keep on trying....Luck be yours and please keep us posted teddy

 

[AMP762]

take the dist. cap off,with ign. on spin it over. should have a spark at the points. if not its most likly points

 

[RustyJones]

I'm assuming your spark plugs aren't all fouled up and are in working order...

Since you replaced the coil, then you know it's not bad.

First thing I would do is inspect the points (pop off distributor cap & rotor). Are the points scorched, or burnt looking? If so, replace. Place a business card in between the points and crank the engine over a few revolutions while sliding the card back & forth. Put it back together (rotor and distributor cap back on) & try it.

Still no start?

Replace the condensor (round looking thing with a wire coming out of one end that hooks up to the distributor primary terminal). If you replace the condensor, I would just get an ignition tune-up kit which should include the condensor, a set of points, a rotor, & maybe a few other things.

Other things to check: distributor cap (cracked, cracks or burnt areas?), spark plug wires (in good shape or old, cracked, corroded).

I'm sure it will end up being something easy. It usually is, but it can a PITA to figure out...

 

[MossRoad]

Maybe the points aren't opening. I'll pull the cap and rotor tomorrow and see. Thanks for the suggestions. It's been many years since I've dealt with points, so I forgot about them /forums/images/graemlins/blush.gif. I went over to How Stuff Works .com and read a tutorial on ignition systems. It was like a slap in the face wake up call.... points, condenser... UNDER the rotor. DUH! I had the cap off and watched to rotor turn around and around and it never occurred to me to check the points. /forums/images/graemlins/tongue.gif

 

[hobbyfarm]

MossRoad,
Don't forget to set the gap on the points too. You should be able to find the spec somewhere.

 

[MossRoad]

I installed new plugs this morning and gapped them to .025.

The point gap is .017 to .022 according to the manual. I will check them tomorrow.

I have a pretty good set of manuals for this thing. I just need to figure out which sections apply to my tractor VS the other variations covered in the books.

 

[Keoke]

Moss Road, with ignition on you should have 12v on plus side of coil but 0 volts on the minus side of coil IF points are closed.
With points open you should have 12 volts on both sides of coil since no current is flowing and thus there will be no voltage drop across coil.
A comon fault when gaping points is that an oil film on the feeler gauge blade will rub off on contacts and act as a insulator preventing the movable contact from finding ground as it should. This gives a mechanical close but electrical open condition, bad news. Clean off film with a none oil based cleaner, acetone, carb cleaner, etc.
Also, a 12 volt test light hooked from the negative side of coil to engine ground should blink on and off while you crank on the starter if all is well with the primary (low voltage) side of circuit.
All 12 volt ign systems have a ballast resistor on the plus side of coil either external mounted or included inside of the coil.
Without this resistor an ignition system running on the full 12 volts would burn up a set of points in short order.

good luck,

 

[_RaT_]

I was going to post you check the points since on every car(s) I have had with points VW bugs to a Datsun pickup, that was the culprit. Bad gap, pitted points were standard problems on the bug.