Ok, so my 318 only has 300 miles on it since rebuild.

Passes emissions with flying colors; smooth running and steady power.

It ran great last week. Now suddenly it runs like crap.

As the RPM’s go up (3/4 throttle –full throttle) it acts like it has a bad miss or like it’s throwing random spark everywhere.

Low RPM’s it’s ok.

It almost sounds like it has a rev limiter when the RPM’s go up.

This is the stock distributor with a pertonix ignitor electronic ignition conversion kit in it.

I have another distributor with points I may just throw on there to see if it cleans up.

Any ideas? Anything else I should look for here? I disassembled the carb before break in and I cleaned it all out. New fuel filter…..

Bad plugs

bad plug/plug wire/Pertronix/rotor phasing/reluctor gap. EDIT rotor phasing may have been on the edge of misfiring but that would not have changed unless something drastic changed with the vac advance & not likely. I'd WAG it's the Pertronix if the plugs/wires are OK. Good visual on the plugs. Might ohm the wires but check the ign on a scope if you could or just sub in another set from another vehicle if available & it wouldn't cost you anything. Yes putting the points back in would tell you if it is the Pertronix. Holler how it goes.

Post deleted by eightlitermopar

Update, I installed my points distributor and it seems to start better, but after the motor is warmed up it is still doing the same thing.

In first gear I'll rev the motor up (1/2 - 3/4 throttle) and it starts to sputter again.

So maybe the distributor is partly the issue, but I am wondering if it's fuel related. clogged fuel line, etc.

I have a new fuel filter on the car, 1 month old.

So here is my list. I am going to

1)fatten up the jets on the carb and then

2) replace all plugs

I checked the fuel pressure and it holds steady from the pump. I am just wonering if I have junk in the line and it's starving at higher RPM....

Any other thoughts?

eightlitermopar

If it was running fine before you messed with the dist, why would you richen up the carb?

Did you happen to get a couple of wires crossed??

Id check the wires for bad/burned spots or the plugs for being fouled. What kind of plugs are you running??

DO THE EASY STUFF FIRST!

If it was running good before, and suddenly is not, and changing the distributor didn't work, stop and back up.
Test the ignition by putting an inductive pickup on each ignition lead and watching the flashes at idle and through the rev range. Non-firing makes gaps in the flashes.
Fuel filter is the easiest to check. Junk in the carb or fuel line is #2. Fuel pump is #3.
Car has been sitting a long time without driving...How about the strainer on the fuel pickup line in the tank? Blow some air backwards through the line to see if your problems go away for a while.
Grounds to distributor and coil need to be checked also. If you are running a ballast resistor it could be failing. Or the coil could be on the fritz.

I had a Holley carb suddenly start to act up, it was a piece of crud in a jet. I have an old ford pickup that has so much rust in the tank that it occasionally plugs up the in-tank strainer.

Neither of these require changing the mixture.

R.

is this a points car or a elect car converted to points?

does it have a points style coil on it?

do you have the BR hooked up?

are they cheap made in china points&cond?

are the points gaped correctly?

is this a re-maned dist or used?

I’m scratching my head here trying to figure it out too…..

So, to answer the questions….

The carb runs good and clean, but it is VERY lean. I am talking like 12%. However, it wasn’t cutting out like this before, it just lacked power at WOT.

The gas tank is clean. Two years ago I was chasing a similar problem and had the tank redone: Meaning I removed it, had it cleaned by a professional shop and the inside coated. I had the tank out in May to reseal the fuel sending unit (it had a small leak). I drained it then and there was no crud in it from what I could see.

I haven’t checked the ballast resistor, and I know the coil is stock. It still has the factory marks on it.

I do have a MSD blaster, Accel, and another 2 stock coils if I need to replace that too.

The wires are 2 years old from napa. I have been careful not to get them crossed. I was double checked 5 and 7 because I have crossed them before. I will inspect every wire again when I check the plugs this evening.

The plugs are also 2 years old, but they are champions. Maybe that’s my problem.

*PLUGS CHANGED UPDATE*

Thanks for the input guys, sorry for the repeat answers, but I wanted to answer everyone’s questions before I gave the update (within the last 20 minutes)

I waited for the motor to cool and changed from my champion plugs to Autolite. I think it runs smoother.

With everything I have done, it runs better when cold.

When the motor gets hot and then I step on the gas, that’s when it starts to sputter and cut out as the RPM’s climb.

I know my carb is lean, and I am running a 195 degree stat in it.

I also don’t have a spacer on the intake, so the carb is right on the manifold.

Maybe its just running too hot and lean?

Maybe the coil or something is cutting out when it gets hot?

Update

So as of today I have done the following:

1) replaced champion plugs with autolite = no change
2) ensured fuel filters not plugged, removed one filter = no change
3) Replaced distributor with another spare one I have, now has points = no change.
4) Tried another coil off another running motor = no change.

However, coming home from one of my test drives, one of my acceleration tests was smoothe and had no stumble

So what's next? I have another carb off our other 318 (has fatter jets in it too)?

I can also rob the spark plug wires off it also.

Any other thoughts at this point?

eightlitermopar

Well, I think I figured it out. I swapped carbs and I have eliminated the problem. When I get some free time I'll have to take the old carb apart and see if there is any crud in it.

I also need to swap back all my original ignition stuff and give them back to my dad's car that I robbed it off of.

Thanks for the help guys, I really appreciate it.

eightlitermopar

So it was fuel not ign . Yeah holler at a later date when you find what was wrong with the carb