Been a while since I posted.. I'm not really sure when the problem developed since I go easy on me car in the winter but since things have warmed up, my '73 has run like crap. It was sputtering, stalling and on occasion, dying. The problem seemed to mostly happen under load. In fact it idles okay - not great, but okay - and revs pretty good too.

I noticed it was running a bit hot (I think my aluminum radiator may have sprung a small leak ) so I topped off the oil and coolant. It seemed to help a little.

Today, I gave the carbs a scratch tune, and got it running seemingly okay. I set the float levels, I set the throttle stops, I set the mixture -everything. It seemed alright, so I took it for a drive, but It was still happening, although not as bad.

I also noticed that when stationary, If I rev, it maxes out at 5K RPM, where it stays. After a few seconds, it will begin to afterfire from the exhaust. Makes me think there's something more than a fuel issue there. Spark plugs look fine. Points were installed maybe 6 months ago, along with a new rotor and dizzy cap and ballast resistor.

Any ideas on what it might be?

My first impression is lean mixture. Round tops or flat tops?

Something with distributor and timing? What is your timing light showing at idle and at 3500rpm

I'm with Blue, check your basics before getting too far. Timing is easy to check and very important. Check static timing and mechanical as suggested, and disconnect the vacuum advance and check its operation if you're using it. While you're there make sure that the new parts you installed didn't come loose and the points aren't pitted. Recheck all of your settings.

If something bad happens within a short time of doing some work I always look at the recent stuff first.

Helps to keep a notebook in the car, write down float setting, mix settings, idle speed, timing at idle and 3000 rpm, dwell, plug condition etc. with the date.

Also vacuum, fuel pressure, and compression if you have the gauges, alternator voltage and anything else that might help.

If you have a stopwatch, you can write down zero to sixty, sixty to ninety, etc. after each adjustment.

Just have to remember where I put the notebook.

I bought a Z a couple of weeks ago and it revs fine but would sputter on the road. Bought 4 Fram G-2 fuel filters and threw them in the tool storage with a palm electric screwdriver. I'm on the 3rd one as of last night. I'm hoping I'll get all the crap out of the tank through those filters, I mount them where the OE one goes by the fuel pump for a quicker swap. I have a finer screen glass one right before the pump but it stays clean. Slow fuel flow leans them out when under load.

  Mark Maras said:

My first impression is lean mixture. Round tops or flat tops?

Round tops. Seems to do it no matter where I putt the mix. Choking it has no change.

  Blue said:

Something with distributor and timing? What is your timing light showing at idle and at 3500rpm

Possible. I won't have a chance to check the timing till Monday at best, but I'll report back when I do.

  Stanley said:

Helps to keep a notebook in the car, write down float setting, mix settings, idle speed, timing at idle and 3000 rpm, dwell, plug condition etc. with the date.

Good idea.

  siteunseen said:

I bought a Z a couple of weeks ago and it revs fine but would sputter on the road. Bought 4 Fram G-2 fuel filters and threw them in the tool storage with a palm electric screwdriver. I'm on the 3rd one as of last night. ... I have a finer screen glass one right before the pump but it stays clean. Slow fuel flow leans them out when under load.

Fuel filter is maybe 6 months old, it looks pretty clear.

I drove it this morning, outside temperate of 81 degrees. It wouldn't start up without some choke, so maybe a little lean (yet it still afterfires, so not really sure on that one). Like before, in first gear it revved up to about 5k. Shifted into second and it made it to 6.5k or so before having issues. I had a similar problem when I switched to electronic ignition, and putting points back in fixed that. It may be the points after all.

The sputtering did not happen. So maybe that only comes into play once the engine has warmed up fully.

Edited May 30, 201410 yr by ninjazombiemaster

Solved. It was the points. They were in horrible shape. They haven't been in there that long. Dropped a new set in today, and its running like a champ. Idles a little high, but probably just needs a re-tune now that the ignition is sorted.

When I first saw the this thread title I expected it to be another Viagra spam. Sure glad it wasn't that kind of problem!

Glad you found the car's problem and it wasn't anything serious.

If your points have worn that quickly, you probably should replace the condensers.

Will you go back to the ZX distributor? I went ahead and got a re-manufactured from Cardone after my junkyard find was JUNK, imagine that. I'm a little nervous putting it in a 240 and the tach still working.

  jfa.series1 said:

When I first saw the this thread title I expected it to be another Viagra spam. Sure glad it wasn't that kind of problem!

Glad you found the car's problem and it wasn't anything serious.

Heh, nope. Just my stubborn car.

  djwarner said:

If your points have worn that quickly, you probably should replace the condensers.

I bought a condenser, too, but haven't put it on. To be perfectly honest I'm not sure they the right one, it looks different than mine and was listed as "Condenser (w/ Dual Points)" which doesnt make sense, but that was the only thing in the system. Makes me a little hesitant to put it in.

  siteunseen said:

Will you go back to the ZX distributor? I went ahead and got a re-manufactured from Cardone after my junkyard find was JUNK, imagine that. I'm a little nervous putting it in a 240 and the tach still working.

Honestly I don't plan on going back to electronic ignition.