New plugs and wires, engine keeps POPping
 

1973.5T

Had a spark jump from the lead into the distributor cap causing a misfire and a stuttering car at part throttle. Changed the plugs and wires today. The spark is gone, but the car is making intermittent popping sounds at idle. You can even feel the exhaust pulse get stronger with each pop. To make things worse, the car feels like it's running on half power.

I replaced one cable at a time to avoid confusion of what goes where. Then again, the Hynes manual does not have a diagram showing exactly which tip on the cap goes to which cylinder, so I can't even double check my work. The cap itself is not labeled either.

I have two more things to go over, maybe a new cap and rotor, and then those infamous points... but I'm not entirely sure what to do to them... Does anyone have any ideas of what may be some possible causes of the pops or what to look for?

Thanks,
Dave.

Check the timing and point dwell (point gap). Adjust as required.

double and triple check your firing order....

Let us know what happens!

Popping can (not always) be a result of a leak in the exhaust system some where between the exhaust port and muffler tip. You should be able to hear the leak.

Re-check the connections at each wire-- sometimes they don't seat in the boots.

Your problem really sounds like a bad ground to the motor. Are your ground straps in good shape? I added a second one from the motor mount to the port chain cover, worked great. Ron has grounded everything to everything else. . . it's that marine experience :)

Pull your dist cap off and you'll see a small line cut into the rim of the distributor. That tells you where #1 wire goes. Proceed clockwise with the firing order.

Cheers,

Joe

Joe,

Thanks. That is exactly the info I've been looking for. Not sure why, but I was having a real tough time finding a diagram that numerically labelled all the nipples on the cap. Thanks to you I have a reference point.

Ahhh... sweet sound of smooth idle. Thanks to all with your patience to deal with same old issues. Turns out after all that even though I changed the wires and plugs one at a time (to avoid a mishap) I managed to swap #3 wire with #5 wire on the cap.

All is well now, but does anyone know whether a conservative (limp mode) 30 mile drive with swapped wires could cause any problems?

Thanks again.

Nah, you're probably OK. Doesn't do any good, of course, but you're not the first.

30 miles is no big deal

Dave, you won't believe how many times I swapped wires while trying to be so careful, that's why I know.

I always end sleeping on it, thinking about it the next day, then going back to basics taking it one step at a time, that is, after getting over my frustration and feeling like an idiot. Amazing how quickly it all gets resolved with a little rest and a clear head.

Cheers,

Joe

Joe,

That's exactly how I felt. An hour's job turned into more like two or three and lasted into the evening. By that time the mosquitos were having their way with me. Consequently I ended driving home and double checking the line up the next day. Guess you learn a bit more each day.