Hi all,
I have what appears to me to be a really strange ignition problem on my TR3.
It's been running like a top for the last few years with a Pertronix ignitor
in place of the points. Just this year I was having this strange experience
where it would start up and run beautifully for varying amounts of time
usually at least half an hour. Long after warm up. Then it would start missing
on a couple of cylinders as if I was running out of gas. If I was close enough
to home I could usually nurse it home with my fingers crossed. A few times it
would just stop altogether and I'd manage to get it off the road...wait around
a few minutes (maybe 5 at most) think about what a drag it was going to be to
leave the car here and get a tow truck. Try to start one last time and it
would start up? Get it home safe in the garage and tell myself I would clean
out the gas tank and lines, replace my two filters because this had to be a
fuel starvation problem. I've made some progress at least in that I now know
that it is definitely not a fuel problem. I have a Facet electric pump and you
can hear it about a mile away ticking. It is pumping plenty of gas to my
carbs. My float bowls are pristine and not stuck. My spark plugs are wet when
I look at them.
Finally had to get a tow the other day when it went through the same series of
symptoms except that this time it didn't start up again. Since then its been
in the garage and I have replaced these parts:
Plugs, wires, distributor cap, Petronix positive ground ignitor unit, coil and
I have replaced the white ignition wire that runs from the ignition key to the
fuse box and then the wire that runs from there to my Petronix box instead of
the coil as I believe it would if I still had points. I measure between 6 and
7 volts at the negative side of the coil when I am cranking the engine (from
the solenoid switch in the engine compartment). I measure very close to the
full voltage of the battery when I turn the ignition on at the ignition wire
that attaches to the black wire on my ignitor. If I remove the wire that comes
from the coil to the distributor and hold it within a half an inch of my valve
cover I can see a small blue spark but nothing very dramatic. I used to be
able to detect voltage with a timing gun that I have on one (only one) of the
plug wires but now I don't detect any voltage anywhere in the plug wires or
the distributor wire...unless I completely remove it as above described and
ground it to the valve cover. If I remove a spark plug with the lead attached
and crank the engine with it grounded against the engine no spark at all.
Nothing.
I replaced the ignition wire from the key switch because when I first
installed the new Petronix Ignitor there was a wire burning, the black wire
that goes to the ignition white wire of the car when I first turned on the
ignition before I even had a chance to get up front and turn it over. It
heated up as if I had connected the Petronix wires backwards but they were
attached just as I had my original Petronix Ignitor. Black/white wire to the
negative side of the coil, black wire to the ignition wire. It does this heat
up deal once....then I rush over and turn off the key...blow the smoke
away...wonder what the hell is going on....turn the key on again and no
smoking. I replaced the ignition wire because I was thinking that I must have
a shorted ignition wire. I guess not because the very same thing happened
after I replace the ignition wire. In any case what I am planning on doing
tomorrow is getting some new points and condenser and go back to the
points....which I have never used on this car. From what I have heard 6-7
volts ain't enough for the coil to get the proper voltage up. Remember this is
a brand new coil, and I have switched between the two with the same results.
My current hypothesis is that I have fried two Petronix Ignitors, my original
and the new one but I have no idea why. And they work no differently now then
they worked before they each heated up and started smoking. Same exact voltage
to the negative side of the coil on cranking. What kind of voltage do you all
get at the negative post of your coil when you are cranking your tr3? Am I
correct in thinking that 7 volts isn't enough?
I am absolutely stumped why one Petronix Ignitor that has served me well for
years would stop working in the weird way that it did, if it did. Has anyone
had an aftermarket ignition module imitate running out of gas on the road and
then start up again? I thought that they either worked or did not. That could
still be the case but I haven't a clue as to what else is involved if the coil
is good, the wires are good, the cap, rotor.....all this stuff was running
like a top except for the aforementioned strange experiences on the side of
the road and finally the tow.
I am wondering what else is in the Ignition system that I have missed or what
else could be affecting the system in that the plugs are not getting any spark
at all?
There has to be something really simple I am missing here.
I'm just glad it's not running at all though as oppossed to running like a
champ for half an hour and leaving me out on the side of the road.
Any ideas would be most appreciated.
Thanks very much,
Jim Lee
|