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A friend of mine has a '89 Ford F250 2WD with a F.I. 302. He had replaced the Ignition Module (attached to the distributor). To replace the module he had to loosen the distributor hold-down bolt and moved the distributor. He asked me to set the ignition timing with a timing light. When i tried to set the timing with the timing light connected to the #1 spark plug wire i couldn't get the timing mark (on the harmonic balancer) to show up. Come to find out after i removed the #1 spark plug and brought the piston up to Top Dead Center, the timing mark on the harmonic balancer was 180 degrees from the timing pointer on the block. Thus the mark on the balancer would refer to Bottom Dead Center when it is aligned with the pointer. I don't understand why the mark would be located opposite of TDC. I was able to set the timing by scribing a new mark on the balancer, measure the circumference of the balancer and divide that measurement by 360 and multiply that measurement by 10 (10 degrees of advance) to get his truck running right for now. But now i'm puzzled about that balancer being the way it was....can anyone explain why?
the distributor could be 180 degrees out but the spark plugs wires to the cap would also have to be installed 180 degrees off.
firing order 1-5-4-2-6-3-7-8 http://www.geocities.com/MotorCity/F...ringOrder.html
It could also be the new module
If its a simple case of just repositioning the distributor and plug wires on the distributor cap, then i would assume i would move the distributor 90 degrees considering that the distributor rotates one degree for every two degrees of crankshaft rotation. Or on the other hand...i could try hooking up the timing light to the #4 or #7 spark plug wire and see if the mark on the harmonic balancer line up with the pointer on the block. I was just wondering if it was a common practice for Ford to index the timing mark on the harmonic balancer at #1 piston Bottom Dead Center.
Last edited by stevieweevie; Oct 21, 2003 at 12:19 AM.
The timing mark is aligned with #1 Top Dead Center. It would probably be much easier to yank out the dizzy put it in the right way. Would save a lot of headaches in case the truck ever gets sold to someone else.
That's what puzzeling me...the timing mark on the harmonic balancer is not aligned with #1 Top Dead Center. I verified that by pulling out the #1 spark plug and inserted a phillips tip screwdriver into the spark plug hole to feel the top of the piston as it rises up to the top of the cylinder while my friend turns the crank by hand using a socket wrench on the crank bolt. When the piston reached it maximum height i checked to see where the timing mark on the harmonic balancer is in relation to the pointer on the block. The mark was 180 degrees away from the pointer.
It's supposed to be TDC on the compression stroke. Someone else already mentioned that you probably got TDC on the exhaust stroke, so it would make sense that it's 180 degrees off. Check again for TDC with the spark plug out, but this time put your thumb over the plug hole and when you start feeling pressure on your thumb, then check with the screwdriver for max height. I'm fairly certain that you will be right on with the timing marks then.
You could also do as previously suggested and just flip the dizzy 180 degrees. You don't even have to worry about rewiring the cap. Just pull the cap off, with wires attached, position it outta the way, pull dizzy, rotate it, and then slap the cap back on.
Top Dead Center, whether it's the TDC on the compression stroke or TDC on the exhaust stroke, will always be the same TDC location on the crank's harmonic balancer for a specific piston. You cannot scribe two different TDC markings on the balancer for the same piston...there can only be one TDC (at the crank). Although i didn't mention it in my original post....yes i did check for TDC with the spark plug out and my thumb over the plug hole feeling for compression....i only did this because my friend wanted to see where the distributor rotor was pointing after i had scribed a new mark on the harmonic balancer for TDC...and yes the rotor was pointed correctly towards the #1 spark plug wire tower on the cap.
Last edited by stevieweevie; Oct 21, 2003 at 12:46 PM.
Most aftermarket cranks have multiple (two) keyways on the crank snout. I don't know whether a 89 Ford does or not. If they do someone, either the factory or later, probably put the balancer on 180 out by using the wrong keyway. The installation of the distributor or whether the engine is on the compression or exhaust stroke has nothing to do with the alignment of the balancer.
It is possible for the rubber ring to allow the outer shell to slip but usually this is only a few degrees. If it has slipped 180 I hope your friend doesn't plan on running any high rpms or the next time you see the balancer may be when it exits the car through the hood or fender.
I just got back from my friend's house today. Out-of-curiousity i tried hooking up the timing light to the #4 spark plug wire (and the #7 spark plug wire). The factory timing mark on the harmonic balancer aligned with the pointer when i did it this way. In fact it was exactly at the 10 degrees mark on the pointer...meaning that the timing mark was a perfect 180 degrees from TDC of the #1 cylinder. I would find it hard to believe that the harmonic balancer could have slipped a perfect 180 degrees, but it would make sense if the crankshaft had two keyways on the crank snout and the balancer had been put on the wrong keyway.
im in the same situation old and fresh engine crank is at top dead center only has one key on crankshaft so if you turn either engine 180 degrees the key is up the groove on balancer is 180 off no matter how times you turn the engine over is a 95 5.0 and 80's fresh 5.0 lifters are in the closed position for the valves
agravating as hell and if i just remark #1 on balancer i have tming tape but wouldnt this through counter weight off? yes crankshaft gear is 2 degrees advanced better low end built a motor this way before curve for cam comes in about 500 -800 rpm earlier and runs out about 500-800 before peak rpm
Last edited by fordman2642; Oct 7, 2022 at 01:48 PM.
