1966 Ford Mustang 200 inline 6 t5. Missfire problem

[whazup8003]

Got my mustang on the recently, and everything seemed to be going good other than the face of a small what seems to be like a missfire once in a while. After driving it for a couple weeks things have just gotten worse and worse.

Here's the setup:
new rebuilt 200 inline 6 bored 30 over
Autolite 1100
New original style distributor cardone (autozone)
T5 transmission out of a 1987 4 cyl mustang


So I finally had all the leaks buttoned up and everything running smoothly
Except a slight missfire through the Rpms. It would miss at idle a little bit too.

I was driving it the other day and it started bucking very violently which is the first time in weeks of short drives it has done this. Almost like enough gas wasn't being given to it off the clutch release. Reminded me of when I was first learning to drive stick and it would buck on unsmooth clutch releases. But I'm kinda ruling out clutch because after this incident it runs real roughag idle to. It will runs smooth and a few seconds later just feel like its misses pretty heavy.

Also on another note I put a new pcv valve on for good measure and it opens and closes to fast and at such a pressure that its makes a ticking noise similar to a knock or a ping noise but I can hear it from inside the car an it's definatly the pcv.
Could this be a cause of the problems I am having?

Been trying to figure this out for quite a bit. Had a few questions that maybe Somone hear could answer that could help me try to solve this problem.

1. What kind of oil is everyone using in there rebuilds?

2. What timing is standard in a rebuilt 200 with a t5? I've heard 12 degrees and 6 degrees.

3. Is there a good way to test a new fuel pump under load? I got a reading of about 6 or 7 at idle. Fuel like is brand new from tank to pump.

4. I have to replace the exhaust gasket donut between manifold and stock pipe. It's leaking pretty bad and was wondering if this could cause my rough running.

5. Have a open hole ahead of distributor in the middle of an emboss. Did a little research and this hole is where a oil draft tube used to go. I plugged it with a freeze plug like is recommended but have a fear it maybe leaking around it still. Would this cause a problem?

6. There is 2 bolts holes underneath the exhaust manifold on passanger side of engine and I don't remember anything going there. Does anyone know what these 2 holes belong too?

I know this is a lot to take in but I wanted to get as much as I could think of out there while it was fresh on my mind. I am probably forgetting something. Any help or comments would be greatly appreciated.

I did quite a bit of searching the forum for this problem in other posts but really couldn't find my exact dilemma spin hope I'm not reporting something someone has already covered.

Thanks in advance Scott

 

[FalconSedanDelivery]

Sadly , most Points equipped vehicles require periodic resetting ( clean and re gap ) on the points , its something that doesn't register with people , I use to do it 2-3 times a year , , Its the first thing I would check , AND , get a dwell meter , NOT a feeler gauge !

 

[bmbm40]

Sounds like a nice Mustang. I am not too good with diagnostic but plenty of smart people on here like FSD. I do know that everyone seems to agree that one of the best upgrades for the money is DSII but your carb is a factor for the swap. It can add 10 horsepower approx and just run way better overall. Look into getting the Falcon Performance Manual available on classicinlines.com, it is all about the six. Did you install the t5 when you rebuilt the engine? How does it drive with the 5 speed ?

 

[powerband]

sounds like early teething problems for the new build...

ignition and fuel problems on new rebuild experience :roll: , leads me to fuel/carb problems , carb/float/needle contamination and ignition basics checked - points,cap,rotor... . Points ignition while not top performance choice, is low on problems once working. PCV rattle and idle problem symptoms could use simple intake Vacuum guage test to see if any hidden vac/valve problems .

if car's been sitting' , clear inline filters before pump and carb has helped . Nominal igniton setting between 6-12 degrees should have adequate drivability'. LOM type distributor works with carb vacuum if equipped, pull and eyeball the plugs,

> I had a week of headaches with a defective DSII before swapping in smooth running original Points system firing up new build 8)



> tight 200 with a T5 makes a sporty package,,,

have fun

 

[rbohm]

8) start with how much vacuum are you getting at idle? if it is low then likely you have a vacuum leak that needs to be corrected. next check your plugs for fouling. it is possible that the inner plugs are very black and in need of cleaning. next check the point gap as already indicated, as well as the condition of the points themselves. if these are good to go and you still have a miss, then advance the ignition timing a few degrees and see if that helps, if it does then go more until you get detonation, then back off a few degrees until it stops. that should keep you busy for a while. let us know how these work out for you.

 

[whazup8003]

checked and reset timing, checked point gap with feeler gauge then dwell meter, reset idle speed screw and idle mixture screw and got her driving again to what I thought was decent. Put the old motorcraft original pcv valve back in cause it still worked just figured newer one for the new engine would be better.

Seemed a little under power but not bad. Drove it for about 10 mins down the road and it started acting up again violently bucking if I gave it gas. As if the fuel or spark was cutting out so I pulled over and waited for the idle to stop jumping then it drove fine for a little longer. But about every 10 to 15 mins I had to pull over to let it settle down when it started jumping.

A friend of mine works at an older garage with a guy who's pretty handy with a carb and set of points so I might have him tow it there and have the old man take a look.

I really don't know what else to do. And the colder weather is on its way, I'd really like to get a nice day to drive her worry free before it comes.

I appreciate all the ideas everyone have given to me. At least I can move it around now

 

[Soldmy66]

Please check your fuel filter.

 

[bubba22349]

How's the gas tank was the car sitting for years? If so it should be cleaned out from your description it sounds like you have crud that's plugging up the fuel pickup. Good luck

 

[thesameguy]

I'd also consider the coil - especially if it gets worse as the car gets warmer. Pretty typical signs of coil failure.

 

[FalconSedanDelivery]

Just found a Bad Condenser in a customers Dist , the problem would come and go , then got real bad , like I said b4 A points system although simple can cause problems

 

[78merKri6]

Whazup,

Careful follow-through on these prior replys should get you fixed. also consider that arcing can happen from around top of the coil to fuel pump/line since its close by.

Sounds like negative lead from coil is broken inside distributor. When advance moves the breaker plate, wire opens-----on/off
circuit, bucking----!!!???

Good luck, have fun.

Gary

 

[chad]

Also been pretty rainy round here, not sure what that would hurt for him, just a thought...