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Pertronix troubeshooting and going back to points?

zray, I'm with you on the MSD parts, hard to beat their choices and I use them on any kind of real performance application. For a stocker or resto app where someone wants the upgrade to be invisible, or they just want to dump the points then the choices are limited to Pertronix and Crane. Also, the price is certainly cheaper on those so they have their place. If you want to make performance then go MSD. The requirements of the ignition system is directly proportionate to the compression ratio and RPM.
 
OK- time for an update. We're still not there yet.
  1. Replaced fuel tank and sender, 10 gallons of fresh gas.
  2. Installed points distributor and timed to 10 degrees BTDC. When rev'd to 3500 timing was 32*. (Recall that coil is brand new after old one was found to be leaking).
  3. Tuned carb with vacuum gauge, got vacuum to a slight stuttering between 18-19 inches. Idle is 850-900RPM.
  4. When reinstalling vacuum advance, timing went to 27*BTDC at idle. (Used manifold vacuum, not ported vacuum).
  5. Replaced FMX vacuum modulator that wouldn't hold vacuum.

For a minute or two I thought we had it licked. We got a much better idle than we could get before the above steps, and the popping out the exhaust slowly stopped as I tweaked both mixture screws on the front of the Edelbrock carb. HOWEVER, the car was stumbling under acceleration with an occasional pop as my son pulled away from the house. I wasn't driving but it sure didn't have the acceleration I thought it should. The car is still not running like it was before all of this... although it is idling quite good now.

Just throwing it out there to see if I've overlooked anything. An engine capable of a pretty decent idle at 850RPM, vacuum is as much as 18-19 inches, and a solid 165 PSI compression all seems to indicate the valve train is ok (to me, at least). It's too late and too cold now to try anything else, but I guess I could test drive without any vac advance and see if the stuttering was way too much timing?
 
OK. I had a stumbling on both cars. I took vacuum advance off and plugged both ends. The dizzy end is just for looks. The problem went away.

I have given this a lot of thought the last couple days. I think it is worth pulling the valve covers and checking the push rods. Also I am wondering if the lifters are hydraulic or solid? If hydraulic you may have a slightly collapsed lifter. It is common when an engine is over revved.

Both are easy to check. I think the things you have done are good and likely needed attention anyway but it is high time to examine the valve train.

Just thinking you may want to measure the valve adjustment at the tappet with a feeler gauge while the car is running. I use an old valve cover we cut up to keep oil from going everywhere. Then check the push rods. You may be able to pick it out just by the gap. It will have a larger gap. After the push rods measure you springs open and closed.

That's a lot so report back.

Mel

Sent from my DROID RAZR HD using Tapatalk 2
 
guruatbol said:
OK. I had a stumbling on both cars. I took vacuum advance off and plugged both ends. The dizzy end is just for looks. The problem went away.
I have given this a lot of thought the last couple days. I think it is worth pulling the valve covers and checking the push rods. Also I am wondering if the lifters are hydraulic or solid? If hydraulic you may have a slightly collapsed lifter. It is common when an engine is over revved.
Both are easy to check. I think the things you have done are good and likely needed attention anyway but it is high time to examine the valve train.
Just thinking you may want to measure the valve adjustment at the tappet with a feeler gauge while the car is running. I use an old valve cover we cut up to keep oil from going everywhere. Then check the push rods. You may be able to pick it out just by the gap. It will have a larger gap. After the push rods measure you springs open and closed.
That's a lot so report back.
Mel
Click to expand...

Thanks for following along and for the ideas. I did pull one of the valve covers early on and cranked the engine to verify (visually only) that all of the rockers were at least operating and that no pushrods were flopping around in there. I didn't measure anything or pull the other cover, but I can easily enough if that makes sense. We have the other unused valve cover gasket as they come in pairs.
By the way, I was surprised to see some sort of aftermarket roller tip rocker. Here's a pic I took. I don't know the brand. I also don't know if the lifters are solid or hydraulic, but would assume based on the mild idle and the lack of any solid lifter ticking that it is hydraulic.
2015_%2B1_%2B6_23_%2B3.jpg


Going to disconnect that vac advance and plug one other suspect vac line for now and take one more attempt at test drive. But failing that, I do agree with you that it's worth looking at the other side too.
Thanks again Mel (and others)!
 
I think I know those rockers, they have no rails for the valve tip, right? If that's what they are they absolutely require either pushrod guide plates or use on early heads with the slotted pushrod holes. If this is what they are then you have rocker arms that are randomly floating around over the valve tips. Pull the other valve cover, Ill bet you have popped a rocker off the valve tip and dumped a pushrod.
 
gsxrken said:
OK- time for an update.
  1. When reinstalling vacuum advance, timing went to 27*BTDC at idle. (Used manifold vacuum, not ported vacuum).
Click to expand...
??
I don't think thats normal. Did you use the proper vac port on the carb ??
Manifold vac drops when pushing the acc pedal , but at that time you need vac to have more advance.IMO.
 
If you measure the voltage at the coil with the wire off the coil and the black wire to ground you will always read battery voltage even though the resistor wire is fine. The reason is you've put the volt meter in series with the resistor wire and in a series circuit, what ever has the most resistance, drops the most voltage. The internal resistance in the meter is so high, it's like that resistor wire is a buss bar. Meters have high internal resistance so they won't "meter load" the circuit. Basically it means it won't change the characteristics of the circuit when measuring a circuit With the wire connected to the coil, you'll get what you're looking for.
 
Figured I should update this thread and thank you all for the sounding board and ideas you provided. We encountered a handful of little things that, all taken together, have the car ripping away now and nice steady idle vacuum of 20".
  1. 2 (two) of his spark plugs were cracked. I had to recalibrate him on necessary spark plug torque.
  2. Big time vacuum leak on the two lines that feed his Cougar's vacuum operated hideaway headlights and something under the dash, probably HVAC related
  3. New cap and rotor
  4. New negative battery cable
  5. Ran new section of engine wiring harness from plug near firewall to hot side of coil
Turned the key and this cat purred. It's his girlfriend's 17th birthday this evening, so he was really hoping to get it square away and we did.
Thanks again!
 
That's great to hear, Thanks for updating us.

From infinity and beyond.

Never argue with a Moron, they'll just drag you down to their level and beat you with experience.

If the women don't find you handsome, they should at least find you handy.
 
Few shots of the car, since we all love pics, right?
You can probably guess there isn't another one in most parking lots...

2015_%2B2_%2B7_22_49.jpg

2015_%2B2_%2B7_22_49.jpg

2015_%2B2_%2B7_22_49.jpg
 
Nice car! Always loved the Cougars. My best buddy in high school drove the wheels off his....good times!
 
Nice looking cat. My Dad's friend from work when i was in high school used to do a lot of dealing with those. If i remember correctly he had a 67 vert and a 68 xr7g bith fully restored. Then ended up loosing them in a divorce.
 
What you gain in a divorce is usually more important than what you lose.

Willie Nelson quote: "why is divorce so expensive ?" Answer: "because it's worth it."

Z
 
whisperer said:
I think I know those rockers, they have no rails for the valve tip, right? If that's what they are they absolutely require either pushrod guide plates or use on early heads with the slotted pushrod holes. If this is what they are then you have rocker arms that are randomly floating around over the valve tips. Pull the other valve cover, Ill bet you have popped a rocker off the valve tip and dumped a pushrod.
Click to expand...

Actually, I not only have a Pertronix I on my convertible and have had for 17 uneventful years, but I also had those self same roller tip rockers on it until I went to GT40P heads and Motorsport full roller rockers about ten years ago. I guess I just didn't understand the dangers of all of those undependable products on one car. Gee, do I ever feel lucky that the whole thing didn't just wheeze and die on me on the spot. Of course I only drag raced it and drove it to L.A. from S.F. about five times and to San Diego once. I can't claim the trip to Birmingham, AL for the roller tips because they were operating on someone else's Mustang by that time still attached to my old stock heads. I've never spun donuts with it but, then, I never quite understood what the point of that was anyway.
 
Grabber70Mach said:
Nice looking cat. My Dad's friend from work when i was in high school used to do a lot of dealing with those. If i remember correctly he had a 67 vert and a 68 xr7g bith fully restored. Then ended up loosing them in a divorce.
Click to expand...
I don't think the Cougar offered a convertible until 69. Thought I read that someplace, but I could be wrong.
 
RagTop said:
I don't think the Cougar offered a convertible until 69. Thought I read that someplace, but I could be wrong.
Click to expand...
Yup. No factory convertibles until the '69 model year. Some 67/68's that have been creatively modified and they do look nice......
 
I am probably wrong on the years it may have been a 67 xr7g and a 69 vert, it's been about 30 years ago. But I do know they were factory cars, he bought parted out and kept the really good ones for himself as a side business.
 
I just replaced the Pertronix with Accel's equivalent in an attempt to get my car running. While I can't confirm the Pertronix is failed, I see a much different spark (better) from the Accel product.

Swap it out if you wish and see what the results provide.
 
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