["70" Cougar]

My 351C gets to about 4500 rpm and then starts acting up.... the only common denominator is the new "ready to run ford msd" distributer. What inside the dist. would let the motor get to 4500 then .. starts popping and making noise and semi cutting out, without cutting out. If it does have a rev limiter built inside would it be so violent?

Thanks alot..

OH I hope i fix it soon... only three more street legal drags left in the season !!!!!

[78novaman]

As far as I know, only the higher up MSD boxes have adjustable rev limiters.

It sounds to me like your timing is advancing too far in the upper RPM's. If you have access to a timing light, I would check your base and advanced timing first. Sorry I don't know fords well enough to know what to set it too.

["70" Cougar]

Hey nova man... well how would the shade tree mechanic do this... im not really sure... Would i just move the distrubuter slightly retarded.. an try from there.. cause i tryed to do that.. and all i got was a sluggish throttle responce .. felt like it was a little delay'd.

thanks
bill

[onovakind67]

Do you have a full 12v to your distributor power terminal, i.e. no resistance wire or ballast resistor?

["70" Cougar]

oh she's right full of 12V... .. could my distributer be out a tooth... ? i know its got to do something with my distributer /timing !

[78novaman]

If you have a vacuum gauge it is easy to check your engine's health. If you don't they are like $20 at Sears or most any hardware store.

Find a place to measure manifold vacuum and follow this: http://www.earlycuda.org/tech/vacuum2.htm

First set your base timing. Leave the vacuum advance connected to your distributor or you will over advance the motor with this method! Hook up the vacuum gauge and place it so you can see it at the same time as your tach. Make sure to either use a free vacuum port on your carb, or use a 'T' so that nothing is unplugged and no ports are open. Start the car and let it idle up to operating temp. If the timing is correct, you should see a steady reading of about 20in. (1st figure) If not, adjust the distributor until you have a steady reading. I suggest the most advanced timing you can get with a smooth idle and perfectly steady vacuum. Pull and release the throttle quick and verify your vacuum drops to just a couple of inches, increases to 25in, then settles back to 20in. (2nd figure). Now pull the throttle slowly, increasing RPM until your miss/stutter comes back. Note what the gauge reads and whether it's jumping around. I would think if your timing is too high the gauge would jump up a hair and fluctuate. Hopefully you will be able to see it in the vacuum gauge before you could tell by hearing/feeling it.


Ah here is the link I was really looking for!
http://www.users.bigpond.com/ergoff/vac1.htm

It's an animated version. If you look on the bottom of the page there is a link to the second page.

["70" Cougar]

Well i may try this... just because..but... i think for some reason that the little vacuum diaphragm that pulls the "Rod" that in-turn rotate's and advances the distributer.. i believe that this rod isn't working right.. could i have a bunk vacuum actuator.. or diaphragm? .. im not sure what its called

thanks man

bill C