Pertronix Woes, is it 1.5 or 3 ohm?

[wild70stang]

Eh, another problem with the stang (not surprised). Ok I believe that a faulty pertronix flame coil is the culprit of my latest snafu. I came across a similar question from this site: MGB: Possible Pertronix Problems
MY QUESTION is how can I identify whether or not I have a 1.5 or 3 ohm coil? Or does it not matter because the coil should be receiving 3 ohms irregardless? I plan to make a trip to the local parts store to rent a multimeter and test my coil to see if its still working. Thanks!

*Just in case I wasnt clear* I just want to make sure which ohm coil I have so I know if the 1.5 or 3 so when I measure if its lower than what it should be operating at.

 

[wild70stang]

Ok I feel a little stupid. Turns out when I first looked at the coil I didn't see any identification, but the second time I wiped off the face and found "1.5" ohm on the top left of the sticker. I used my gf's fathers TPI 120 multimeter and tested the coil (off the car) which registered at .002. I know a multimeter should be set to zero when reading ohms, but this one says 1. (number 1 and a decimal point). (If I am reading it right) I am surprised my car ran at all with that low of a reading.

Is there any coil I can use instead of the Flame thrower? I have heard if you use a different combo it will cause problems.
Well hope this will help future people, since I couldn't find anyone with the symptoms I had I will go a head and do a write up.

It began after 2 minutes of driving because at the first stop light the car began to shake hard enough to knock your socks off. Brought the car back and it sat for a week before I started her up and the car ran fine . Then a few days later after driving about 2 minutes again it started again . Thought it was a carb issue since it only happened while the car was idling (ran smooth above 1000 rpm), but I had recently dunked the carb in a gallon of parts cleaner. I even blew out the idle screw ports in case any trash in the lines clogged it up. The symptoms sounded like an ignition miss and shortly after researching on some random site, bingo.

Sorry for spamming everyone with Q's, just trying to learn. Loved all the feedback I have received in the past!

Also want to say that the PO installed pertronix crap in the car, just kept it going. Plan to install MSD or more RELIABLE ignition sources later on

:SNSign:

 

[67GTFB]

VOM and Pertronix coil ...

you didn't mention the ohm scale of the VOM, so it *could* be that the meter was reading kiloohms where .002 Kohm = (approx) 1.5 ohm .... try the meter at the lowest ohm range as possible ..... also, make sure the meter reads "0" with the leads shorted (but you knew that) .... FBOW, I have a Per 1 and it works fine with the 1.5 ohm Flamer coil .... with Per's you do need to ensure that full battery voltage is supplied to the "+" side of the coil and bypass any in-line resistor or resitance wire from the orig harness .... low supply voltage at the Per coil can cause poor ign performance - another thing to examine .... btw, the Per 2 unit needs the 1/2 ohm coil and won't work with the 1.5 .... assume that's not your problem though .....

good luck ....

67GTFB

 

[wild70stang]

update

you didn't mention the ohm scale of the VOM, so it *could* be that the meter was reading kiloohms where .002 Kohm = (approx) 1.5 ohm .... try the meter at the lowest ohm range as possible ..... also, make sure the meter reads "0" with the leads shorted (but you knew that) .... FBOW, I have a Per 1 and it works fine with the 1.5 ohm Flamer coil .... with Per's you do need to ensure that full battery voltage is supplied to the "+" side of the coil and bypass any in-line resistor or resitance wire from the orig harness .... low supply voltage at the Per coil can cause poor ign performance - another thing to examine .... btw, the Per 2 unit needs the 1/2 ohm coil and won't work with the 1.5 .... assume that's not your problem though .....

good luck ....

67GTFB

*update*
The first multimeter was wierd. Yes I do know about touching the wires, though that one read 1.0. So got a diff multimeter and made sure it worked (which it does). Turns out that my ignitor module is fried. I tested it per pertronix instructions. It was suppose to read a fluctuating current, but it read a constant 11.5 which = fried like KFC chicken. Hope this can help someone else.

 

[66GT305PS]

Not sure about the electronic challenges, but I installed the Petronic system as directed in both the wife's 1968 (289 ci) and the dual point in my 1966 GT350 and have had no problems. The cars start right up once fuel gets to the carb (if they have been sitting for a few weeks), usually on the scond crank. Got rid of the MSD system because self and friends found too many problems with starting the car, especially if the system got hot. I am now thinking of upgrading to the Petronix II system.

 

[zookeeper]

I have a Pertronix II in my car and love it. It fires right up and runs smoothly, but the part I like best is that if you accidently leave the key on, it doens't hurt it. I did this not onece, but twice while tuning the carbs, and left it on long enough to drain the battery, yet the ignition module is still fine. Before you get too worked up about labeling Pertronix "crap" you should know I've had factory GM modules fail in nearly new cars, yet I don't hear anyone calling their ignitions crap.

 

[wild70stang]

Pertonix is OK, its just I would rather have MSD or something that is a little more reliable.

 

[wild70stang]

*What is the best sealant that you guys use for the gaskets for the carb? I think my issue is a vacuum leak even though i did spray for it, but I will get a bottle and check again. Since the problem didn't rear its ugly head until I tried to swap the Carter with the Autolite.

So.. after I changed out the pertronix Ignition (I did test it thoroughly and IT WAS FRIED!) started the car AND.............the symptoms were back .... I changed the Carter AFB out with the Autolite 4100. After the swap I started her up and she ran fine...until I turned off the igntion and started her back up and noticed that the symptoms were BACK !!! Initially, before I changed the Ignitor out, it couldnt start and now after replacing it it can start but it idles like crap (yes the previous module was broken). Again the car runs perfectly fine above 1000 rpm.

I replaced the spark plugs and spark plug wires four years ago, and If I get the time (drowning in Graphic Design projects as usual) I will examine the plugs. I have not checked the valve lash (I obtained the procedure courtesy of D.Hearne ) since I bought the car, of course I had to listen to my brother (ex army mechani, he said dont worry about it). The car had the engine rebuilt by the previous owners (about 7 years ago saw the bill for it).

I rebuilt both carbs, I even took apart the autolite one last time before I slapped it on the car. I have brand new gaskets from the top of the manifold to the airhorn.

with Per's you do need to ensure that full battery voltage is supplied to the "+" side of the coil and bypass any in-line resistor or resitance wire from the orig harness ....

67GTFB

Yes I do have 12 volts running from ignition module on the steering column. I did this when I purchased the flame thrower coil.

One last thing...It just dawned on me that I forgot to plug the choke housing... So when I get back around with fiddling with the car I will plug that up first.

 

[wild70stang]

*UPDATE*
Still not working. I bought a gasoline/oil resistant sealant (same stuff I have been using for a while) and waited 48 hours since it has been about 50-75*. I pulled the plugs, they were slightly dark only because after switching to the autolite the secondary float is having issues and dumped a large amount of fuel into the engine (I checked three plugs before this incident and they were tan). I did notice however as I held the throttle open my hand felt similar vibrations as it does when it idles. The ignition timing has not moved in the last 2 years. My thoughts are now leading towards the valves. I uploaded two videos, first one is the vacuum gauge reading (fluctuates between 11-12psi) and second (if you can hear) is the sound out the tail end. I do want to mention that the car does idle alot lower than with the carter (with the carter the symptoms are much more noticeable). From the tail pipe end it sounds like many miniature puffs vs the regular solid few puffs. Again I apologize if I am being an inconvenience and I appreciate any help.

*Went back and checked the valves...yea they are all loose. Only 3-4 I could really spin without any resistance, others had slight drag. If these valves are not my problem and no one can help me I am going to rip out my hair and take the car to a mechanic

YouTube - Car troubles

*edit* if you need the sound clip to help diagnose the issue I will send you the link for the exhaust clip (stupid me got the license plate in the shot).

 

[wild70stang]

So have I stumped everyone or are you guys just tired of me ?

 

[zookeeper]

You've gone through so many variables, it's tough to even venture a guess at this point, but here goes: electronic ignitions don't get weak, they either work, or they don't. Having said that, I suspect your ignition is fine. What was it that made you suspect valve problems? Hydraulic lifters are generally a "set it and forget it" proposition, unless you're pulling studs out or the valves have begun sinking into the seats, but then they'd be tight, not loose. Either way, I don't think the valves are your problem. That leaves the carb. The fact that you're using any kind of sealant at all on your carb says it all. Never, ever, ever under any circumstances whatsoever should any sort of sealant be used on the carb. If you have a vacuum leak, either the manifold surface isn't flat, or the carb base isn't flat, or the carb isn't tight. If you need to use sealant of any kind somewhere on the carb, you did something wrong. Gas is sealed by gaskets and o-rings. Air is sealed by gaskets, dry gaskets. If I were you, I'd buy a brand new carb. Not rebuilt by a friend, but brand new. You need to establish a baseline in tuning and any carb that's had sealant on it, likely has sealant IN it as well. I'd bet on it.

 

[wild70stang]

Sorry about sounding frustrated. Just figured I nagged people to death, as I have a tendency to do that.

I do understand that electrical parts can suddenly give out and have no warning symptoms.

Before I used sealant around the carb I did test it with a spray bottle with water/soap...no luck. The gaskets were brand new from the rebuild kit I received from Carburetor.ca and rebuilt the autolite so I just though I might as well try and eliminate the possibility of a leak. The carter was working fine and even after the symptoms I tore it down and inspected it and it seemed fine.

I was going through my Chilton and read about valves being loose or not seating that can cause poor idle. They were really loose and I plan to adjust them soon, but I wont know if it made a difference or not since the cork gaskets tore :mad, which of course are not meant to come off as nicely as the rubber 1's.

If I end up buying a new carb I almost want to either send the autolite to Pony Carbs or just buy another Autolite since I love its simplicity and my car sounds/feels alot smoother with it (the carter was a bit aggressive and killen me with gas mileage).

Thanks for the help Zoo.

 

[mustangman1974]

yeah bad valves can cause problems when the car warms up. So can weak springs. I would adjust the valves. Just out of curiosity have you tried plugging you PVC valve. I had one go out that mad my car idle like ****.

 

[wild70stang]

I did change the PCV out last december, though the gasket that holds it in place is crap, I can pull the valve out like nothing. I will try and clean that part. Also, do I need to clean out the oil filler cap?

 

[zookeeper]

The filler cap is designed to keep dirt out and not much else. If it's drooling oil, it's a sign of blowby, but unless it's severe, it's normal. The loose PCV can be a problem. Since it attaches to the intake, if it's loose it's a vacuum leak, so get a new grommet or hose (or both) just for the peace of mind. Other places for a tough-to-spot vacuum leak are the vacuum advance hose on the distrubuter, the vacuum hose going the transmission shift modulator and any possible power brake vacuum supply hoses. These all need to be tight and soft. Just one other thing that I've seen in the past: is your engine using a bit more oil than usual? I once had a vacuum leak under the intake manifold. It was sucking air (and oil) into the intake from the lifter valley, causing symptoms a lot like you're describing. Just a thought.

 

[wild70stang]

When I pull the plugs there is oil on the threads, and I do notice a bit of oil consumption, but since I haven't been driving it much (before the symptoms) I can't tell exactly how much is being swallowed. So is there any other way to test that theory? Icky. Well I am probably going to order the gaskets as I think there might have been a internal leak building for sometime (just a hunch). Any other gaskets for the intake manifold that I need to be aware of before I purchase them? Thanks

*edit* Oops, had a brain fart. Why don't I do a compression check. DUH! lol.
Also, I probably will change the head gasket if I change the intake gasket since the engine was rebuilt about almost 9 years ago.
Also what type of sealant do you guys use for the intake (want to do the job right the first time).

 

[zookeeper]

Don't pull the heads off unless there's something really wrong. Exploratory surgery rarely goes well. The intake gasket is a quick job, but again, make sure that's the problem beforehand. The symptoms will be one or two extra dark or oil-fouled plugs, likely right next to one another, oil smoke or consumption and an erratic idle. If you do swap out the intake gsakets, I prefer Permatex Ultra black sealant. I use a genrerous bead in front and back instead of the cork end gaskets and a thin coat around the water passages. That method hasn't failed yet, but lots of people have their own way that works for them as well. Also, how new are your plug wires? A burned or crossed wire can drive you nuts, as can carbon tracking in the distributer cap.

 

[wild70stang]

The wires are three years old, not cracked or burnt. I checked the line for the transmission and it looked good, no cracks. I took a picture of two spark plugs (including the one I said was a little darker) and the dizzy cap. The wire that leads to the coil looks like its pretty worn, should I replace the cap? When I tackle the valve adjustment its going to be a pain! I'm going to jack up the car and wiggle my wrench past the transmission line that leads into the radiator.

So as a recap I have a dirty spark plug, loose valves, float issue with the autolite (part on the way), and a giant headache

The images can be viewed here:
Wild70mustang

 

[zookeeper]

Did I miss something? Why are you doing a valve adjustment from under the car? That plug in question looks just fine for a carburated car, they won't all be equal.

 

[wild70stang]

My plan was to remove all 8 plugs and turn the pulley manually, what I said earlier was my backup plan since I dont want to remove the p/s bracket and water pump to turn the motor. I know the plugs look fine, I was just pointing it out. I figured that cylinder picked up a little more fuel during my float problem. When I am done adjusting the valves I will report back