Timing problems

[Tim Brewer]

I have a MSD pro billit and a 6al box. The other day I had to remove my dist. to fix a stripped out T. housing bolt. I carefully marked my dist. location and the rotor location as well. I carefully put everything back together, just like it was. So I started her up and noticed the engine sounded quieter than normal. I set the initial at 16, hopped in and went for a test drive. It had no power and would backfire if I gave it too much gas. So I figured the timing to be all wrong somehow and pulled the #1 plug, had my wife turn the engine over until I felt compression. I then hand turned the engine over to 0 deg.( it landed on 8) and made sure the rotor pointed to #1 which it was. So, I started the engine again and no improvement. I noticed that all the headers were hot except for #4 and #8. I then pulled one at a time the #4 and #8 plug wires, put in an old plug, grounded it and started the engine. Both 4 and 8 were sparking, but it seems these two cylinders are not fireing. I've gone through this procedure twice now, what am I missing?? Any ideas?
Thanks,
Tim

[millennium200]

Tim,
Just a guess is that you did not get to TDC on the number one cylinder. I am sure you know that you will feel air coming out twice on any cylinder for each crankshaft revolution. The best way I have found to find true TDC on the compression stroke is to take the passenger side valve cover off and watch the number one cylinder intake valve rocker. When the intake valve on the number one cylinder opens and then closes watch for 0 on the harmonic balancer to come up to the pointer and that will be TDC on the compression stroke.

Just my best guess,

[392cobra]

A weak or bad wire/plug can fire when not under the high pressure of the cylinder.The high pressure/compression in the engine can prevent a weak spark from jumping the spark plug gap.

Put an ohm meter on the wires and watch the reading as you moved the wire and terminals around.

I betting on bad wires or terminals.

[Dwight]

With the engine running hot I think the timing is off. Pulling the value cover is the better way to find TDC. Some plug wires are copper core and have little or no resistance. The newer ( carbon core ) have a resistance from 100 ohms to 1100 ohms. The 100 ohm wires are better. Dwight

[Tim Brewer]

Thanks guys for your replys. I had a buddy of mine come over to take a look at my problem. The car would start,(but on six cylinders), so he just reved the engine and turned the dist. until it came to life and sounded good to his ears. I wanted to get the timing light out and he said not to worry about it. This guy was a ford master tech. for many years. The car would miss slightly on lower RPM's but really run good over 3 grand. But it didn't want to start easily ever, so I knew it must have been advanced alot. So today I put a light on it and it was set at about 50 deg. TDC! I brought it back to an initial of about 18 deg. and now it of course it starts better. But, annother problem is that I don't seem to have any advance, and my engine still runs hot. I think maybe I need to put my dist. on one of those machines that checks your advance, if I only knew where one was. Any thoughts?
Thanks, Tim

[Excaliber]

The MSD distributors ship from the factory with TWO heavy silver springs. These 'stock' springs do not allow much mechanical advance until you reach pretty high rpm. Perhaps as much as 4000 or so.

On the MSD web site you will find 'charts' and 'graphs' that show you WHAT springs to use to get advance at varying rpms. It also shows what 'stop bushing' to use to limit the max advance allowed. Typically there is a BLUE and a BLACK 'stop bushing'. One allows something like 25 degrees max advance, the other only about 18 degrees.

HOW FAST and at WHAT RPM the advance BEGINS and finally reaches MAX is determined by the various springs or combination of springs. For instance I would recommend the black stop bushing with ONE heavy silver spring and ONE light silver spring. This will give you about 18 degrees total and max advance will be reached around 2800-3000 rpm. Advance will BEGIN around 1500.

BASE timing of 18 PLUS mechanical advance of 18 equals a TOTAL advance of around 36. Possibly a bit to much, but it's almost impossible to 'dial it in' to exact numbers without sacraficing something some where. Like poor idle because the base timing is to low, or a lag in throttle response at lower rpm, but runs great at high rpm. Always a trade off some where.

The distributor must be removed and partially disassembled to replace the 'stop bushing'. Your in pretty deep here if you don't understand 'distributor basics'. You don't really need a distributor machine, you DO need to understand HOW the MSD springs, weights and stop bushings work. Without that a machine would be a waste of time anyway.

Shoot for (feel free to chime in here guys):
Begin advance at 1800 - 2000 rpm, end max advance at 3000 - 3200 rpm. Replace bushings and springs as required to hit that target, GRAPHED on the MSD web site.

[392cobra]

What type timing light are you using ? A digitial and a dial back can give you bad readings.

With the rotor off does the advance move freely ?

[Excaliber]

Heres a link to the MSD web site, click on "Top Ten Questions" and a PDF will load with the graphs for spring\rpm selection.

http://www.msdignition.com/1support.htm

[Jerry Clayton]

Ernie

Once you do enough bushing changes, you can develope the ability to not only do them without taking the distributor apart, but can do them without removing the unit from the engine--

I generally end up with the black bushing, middle springs on the hotter cammed engines with around 14 initial which keeps the total below 35-36 --we have cheaper gas here than in Hawaii--don't know if the quality is equal but I definitly stay below 38(generally)

What do you do now that the race tracks have closed??????street race???

Jerry

[Excaliber]

Well since the track closed and street racing was highly 'feared' as a reality by the police they just passed some VERY tough laws concerning it.

25 mph over the posted speed or 80 mph at any time is mandatory license suspension, 30 days I think, possible JAIL time and a HEFTY fine as well. A 'race' ticket could cost you your car!

[rdorman]

Sounds like the dist is off a tooth to me. Exact same simptom cured many times by getting it right. I use a remote starter to bump the engine until is is coming up on compression (you will feel the difference from the exhaust stroke) and them turn the motor by hand (be sure it you are turning the correct direction) until it at the initial timing. Index the the cap to the dist and then drop it in so the rotor points dead on the terminal, if in doubt, drill a hole in the cap and you can plug it later (often do that but that is another story). Put a volt meter on the the coil, turn ignition on and carefully turn dist until voltage drops. Double check rotor to cap relationship (You can turn it either way to get this to work but what you want to end up with is the best cap to rotor relationship). Start car, recheck timing. Works every time...... unless of course something is broke!

[392cobra]

Great tip Rick.

[ByronRACE]

Useful tool:


http://www.northerntool.com/webapp/w...rfno=200312010

[rdorman]

I was thinking about this on the way home and I don't think I was clear about what I meant when I said 'index'. I am not talking about removing the locating tab from the cap, drilling a hole between the number one terminal and the coil terminal (I do this from the inside so I can make sure it is perfectly in line between the two and I also drill the hole the same diameter at the terminal on the inside of the cap) and then positively locating the cap in the perfect position...

All I meant is to bolt, clamp, screw the cap to the distributor and using a straight edge, mark the cap and distributor directly in line with the number one terminal. Ideally, the rotor will point dead center of the cap terminal in the middle of the advance range. So say you run 36 degrees total, the rotor will be dead center of the terminal at 18 degrees. Remember that the dist fires every 45 degree and with 20-30 degrees of advance, if it is off a little bit you can see that it may easily fire the wrong cylinder or two at once (particuarly on the small caps, why do you think many have such big caps!). Whenever you pull a dist and get a bad miss at say idle and it runs fine at speed (or the other way around) and/or you have to set the timing way out of whack, this is probably what you have going on.

I like to go through the whole deal with any new combination and use a little silicone plug to fill the hole in the cap. When I replace the cap, I compare the two and if it looks good, just bolt it down (lazy!)

Of course if he pulled wires, be sure they are in the right location!

ALWAYS use the procedure above when firing a new motor (and of course five minutes or so of good pre-lube and a know carb full of gas)... your cam will thank you