Firing Order Has Me Fired Up.....

[JRHARRIS24]

Hello everyone!
Just like a lot of people on this forum, I need help.

I have a 1989 MGM 5.0. It's a great car, near new condition just rolled back over to 00000 miles.
Now for the problem, I just did a tune up on it because EVERYTHING is original 1989 and it felt like the plugs were fouled out.
Anyways I put on new: plugs and wires, new coil, and a whole new distributor because I found a crack in the base/stalk.
So after re-installing everything and using the 1-5 firing pattern for the non-HO 302's it wouldn't fire.
I thought maybe I had the dizzy a little off from my install, so I brought it up to tdc and then to the 10 degree mark on the crank. set the dizzy to #1..... and still no start. You could hear it pop in the exhaust like the timing was off. I was stumped, but I remembered seeing H.O. stamped on the original dizzy, so I set it to the 351/H.O. firing order just for s**t's and giggles, and Bam it started. WTF. Granted it ran like total dog crap, missing on like 3 or 4 cylinders (because I dont think its the right firing order), but it gave me enough time to get the timing set with the light. (10 degrees btdc). I cannot get the car to fire off when it is set to the 1-5 firing order though.... and I know that is what it was at when I parked the car, I marked the wires.

My question is HOW will the car run on the wrong firing order, but not the correct one? Has this ever happened to anyone else? I have searched and searched but cannot find where this is posted previously. If anyone can help it will be so greatly appreciated.

[JRHARRIS24]

Ockham's razor suggests that this is simply a bad distributor, I'm and idiot, or its actually a 351/H.O. with a 5.0 plate on the intake, but I put the old distributor back in, and it would only run on the 351/H.O. firing order, like crap, just like I described, and wouldn't start on the 1-5 firing order. So I am at a loss. ��

[friskyfrankie]

It HAS happened before but you will eventually need to verify the correct engine to ensure the proper firing order. Until you do that, you'll simply be chasing your tail.

[JRHARRIS24]

okay, let me see how to identify this and I'll go from there. Thanks

[sly]

Double check the vacuum lines to make sure you didn't accidently break something. If there's enough of a vacuum leak, it won't run either.

[JRHARRIS24]

First thing I did lol. Oh how I love Vacuum.

[87gtVIC]

Pull number one plug out and turn over by hand and feel for compression. Re set distributor so rotor points to where number 1 is on the cap.

Follow this diagram for the 15426378 firing order.




You do not have a 351. Far to much would have to be changed to retain stock appearance...sefi. I also highly doubt it was converted to HO.

[JRHARRIS24]

I will give it a shot again..... Maybe I'm 1 plug off on the cap where I set the distributor. I know those things have to be pretty much spot on to work correctly. Am I right?

[friskyfrankie]

Sometime they will start when off but will certainly NOT run well. Spot on, no vacuum leaks and proper timing will all work together to produce the result you need.

[JRHARRIS24]

I've been working non stop. So I haven't got a chance to check to see if that was the problem. I will check it this weekend and see if I can get 'er fired up. I did see that she is a 302 and I'm not crazy lol

[Kodachrome Wolf]

Just a dumb question, when setting the timing, were you on the BTDC side or ATDC side of the balancer?

[JRHARRIS24]

So, the I found the Timing marks, and I used the straight timing bracket to set the timing.... Now that I think about it there was a circle that was on the timing bracket as well. Is that what I should have used? This is only my second Ford that I've really worked on. My last had a 4.9 I6 and that is the closest ford engine that is like working on a Chevrolet. I like these cars, but I have been working on Chevy and Dodge, and a whole slew of newer computerized crap all my life.

[VicCrownVic]

The circle, if I'm not mistaken, was for mounting some special tool. The point of the timing indicator is what you want to line up with the timing mark on the balancer, as long as that little bracket hasn't somehow been moved, twisted, or tweaked.

I was thinking the same as Kwolf, there are ATDC and BTDC marks on these balancer. BTDC is where you want to be. Also when checking timing you need to pull the spout connector.

[JRHARRIS24]

Yes! the wonderful spout connector, a headache of the recent past. I figured that one out pretty fast lol. Most of the pre-obd II have some sort of disconnect for the ignition timing.

So I set it by the correct timing mark, at least i think so. The balancer was pretty rusty. I will double check for the btdc and atdc timing marks.

[kishy]

Something to consider as well: the balancer ring might have slipped if the rubber is really dried out/missing chunks. I'll suggest verifying TDC on cylinder 1 roughly matches the balancer (and keep in mind that Ford numbers cylinders differently than everyone else - which I'm sure you already know, but just in case you don't...).

I've done this in the past by sticking a wire (might have been a piece of household Romex-type stuff) in the plug hole and guesstimating when it felt like the piston was all the way up.

Unscientific and inexact, but as long as you're within a bunch of degrees and not crazy far off, it should be good enough to work and then adjust from there.