My engine stopped running. 86 258 CJ7 stock. I knew the timing chain was going. so I replaced it. Still couldn't get it running, turned out I put the cam gear in 180 degrees the wrong way. Fipped that around, put it back together. Cranked it again and no explosion. Smelling fuel, getting fuel, checked the spark, was weak. Replaced the coil, cap, rotor, plugs, and wires. Still no start, checked the rotor position it was out of position at TDC, it was about at postion 2 on a 1, 5, 3, 6, 2, 4 firing pattern. So I pulled the distributor out and repositioned it to the #1 position at TDC. Still no explosion.
I have fuel, spark, and presumably air. What else can I check or do?? My brain is tapped as far as knowledge. Would the ignition module have anything to do with this? Am I getting to much fuel? Any ideas????
Also any web pages on proper timing. I'm only 87% sure I have the cam and crankshaft in the right postions.
Last edited by jonesmatty; 09-04-2002 at 03:16 PM..
The gears for the timing chain only go on one way. As long as the two dots on each gear are lined up with each other you have the cam and crank lined up correctly. Are you sure that the #1 cylinder was at TDC on the compression stroke and not on the exhaust stroke?
The only thing I'm sure of is that I had the two dots lined up. The cam gear has 36 gears on it and the crank has 18, which means that twice around on the crank the dots line up again.
How can I be sure that the #1 cylinder was at TDC on the compression stroke and not on the exhaust stroke? And how much of difference would that make? Would that cause it to be so out of time that I would get no explosion or anything significant enough to notice?
As the previous letter stated.....make sure you are on compression stroke.
The easiest way to do it is to rotate the engine with the plugs removed and place your finger over the spark plug hole of #1 cylinder.
As you feel the push against your finger note the position of the timing pointer on the balancer. Bring it up to TDC and check your rotor position. You seem to have all the other necessities!
Computerized Marine Diesel, IPS Systems
'06 Rubicon Unlimited
Originally posted by jonesmatty How can I be sure that the #1 cylinder was at TDC on the compression stroke and not on the exhaust stroke? And how much of difference would that make? Would that cause it to be so out of time that I would get no explosion or anything significant enough to notice?
Uhh yeah, that would cause a problem. Setting the distributor must be done so that the no. 1 cylinder is at the top of the compression stroke. There are four strokes. Intake (down) has the intake valve open and the air/fuel mixture enters the cylinder. Compression (up) is the compression of that air/fuel mixture to a more volatile state. Power (down) is what happens as the spark plug ignites and the explosion forces the piston down. Exhaust (up) is the expulsion of the burned gases with the exhaust valve open. If the spark is sent to the no. 1 cylinder on the exhaust stroke, there is nothing in the cylinder for the spark to ignite! Also, the exhaust valve is open so no compressed air/fuel mixture is there to fire. The whole idea of timing is "timing" the spark going to each individual cylinder with the related cylinder's compression stroke.
I finally got that all set. I now know where TDC is, (didn't read this and took the valve cover off, need a new gasket anyway.) Put #1 on TDC and re-re-realigned the distributor and rotor so it's pointing at #1 spark plug wire. Now if I only hadn't killed my battery or had something better than a trickle charger, I could test it.
Thanks for the advice, I fill y'all in later with the results.
Still didn't work. Have plenty of fuel, (plugs are wet with gas), quadruple checked spark, and air has to be flowing. I didn't adjust anything on the carter carb. I noticed that I have the ECM bypass. I wonder if that has anything to do with it? Any ideas whatsoever would be helpful.
I am now the proud owner of the "******* of the Month" award.
Note to self: when putting timing gears in use better light to find the "real" punch hole on the cam gear.
Yes I was out of time, I was using the little hole opposite the dowel coming out of the cam shaft as my timing mark. I pulled the cover off yet again to find THAT "little" mind blurp. It only cost my 3 days of work and 1 migrain headache.
Thanks to all for the help. She purs like a kitten now. I don't even have to shut off my engine at drive thrus anymore!!